ISFM Consensus Guidelines on the Diagnosis and Management of Hypertension in Cats

Effect of oral administration of pregabalin on physiological and echocardiographic variables in healthy cats

OBJECTIVES

The aim of this study was to evaluate the efficacy of a single dose of oral pregabalin (PGB) for sedation and its impact on physiological and echocardiographic variables in healthy cats.

METHODS

This study was a randomised, blinded, crossover trial. Eight cats were randomly assigned to receive PGB or placebo, with a 1-week washout period between each administration. Cats in the treatment group received oral PGB at varying doses (low dose: 2.5 mg/kg, medium dose: 5 mg/kg, high dose: 10 mg/kg). Systolic blood pressure (SBP), pulse rate (PR), respiratory rate (RR) and sedation score were measured at intervals of 30 mins after administration. Echocardiography was performed 120 mins after administration.

RESULTS

Oral administration of PGB 2.5 mg/kg and 5 mg/kg significantly increased sedation scores starting at 150 mins, while 10 mg/kg PGB showed a significant increase in sedation scores starting at 120 mins compared with placebo. PGB 5 mg/kg and 10 mg/kg resulted in a significant reduction in SBP compared with placebo, with minimal impact on PR and RR. In addition, PGB 10 mg/kg resulted in significant changes in the peak velocity of late diastolic transmitral flow (A) and the ratio of peak velocity of early diastolic transmitral flow and A; however, these changes were of marginal clinical significance.

CONCLUSIONS AND RELEVANCE

A single dose of oral PGB could cause mild to moderate sedation. Hypotension was more prevalent in the PGB 5 mg/kg and 10 mg/kg groups among the majority of cats, but it was less frequently observed in the PGB 2.5 mg/kg group.

Blood pressure in hyperthyroid cats before and after radioiodine treatment

BACKGROUND

Hyperthyroid cats commonly have systemic hypertension, with a reported prevalence of 7% to 48%. Although hypertension might be expected to resolve once treatment restores euthyroidism, it can persist or only first develop after treatment.

OBJECTIVES

To determine the proportion of hyperthyroid cats with hypertension (systolic blood pressure [SBP] ≥160 mm Hg), persistence or first development of hypertension after successful radioiodine treatment, and correlation of post-treatment hypertension with azotemia or hypothyroidism.

ANIMALS

Four hundred one hyperthyroid nonazotemic cats were included in the study.

METHODS

Prospective, cross-sectional and before-and-after studies. All hyperthyroid cats had SBP measured by Doppler; 255 had SBP rechecked 6 months after successful radioiodine (131I) treatment.

RESULTS

Of untreated hyperthyroid cats, 108/401 (27%) were hypertensive. A higher proportion of hypertensive cats were nervous/excited compared with normotensive cats (47% vs 12%; P < .001). Of the initially hypertensive cats, 87/108 cats were reexamined after 131I treatment; 43/87 (49%) cats normalized SBP, whereas 44/87 (51%) remained hypertensive. Of the initially normotensive cats, 16/168 (9.5%) first developed hypertension after successful 131I treatment. 7/60 (12%) of the 131I-treated hypertensive cats were azotemic and 9/60 (15%) were hypothyroid. A higher proportion of cats remaining hypertensive had nervous/excited demeanor than did normotensive cats (50% vs 17%; P < .001).

CONCLUSIONS/CLINICAL IMPORTANCE

Hypertension, when present, resolves in many hyperthyroid cats after successful treatment. Hyperthyroid cats uncommonly develop new hypertension after treatment. Persistent or newly detected hypertension was unrelated to azotemia or iatrogenic hypothyroidism. More frequently perceived nervousness/anxiety in radioiodine-treated hypertensive cats suggests that many of these cats might have "situational" hypertension, as hyperthyroid-induced hypertension should resolve after treatment.

Assessment of hemostasis in hyperthyroid and euthyroid cats using two viscoelastic assays and platelet aggregometry

BACKGROUND

Hyperthyroidism in humans is associated with a hypercoagulable state and an increased risk of thromboembolism.

OBJECTIVE

To evaluate hemostatic variables in hyperthyroid and euthyroid cats with the hypothesis that hyperthyroid cats will have evidence of altered hemostasis consistent with a potential hypercoagulable state.

ANIMALS

Client-owned hyperthyroid (n = 16) and euthyroid (n = 15) cats over 8 years of age.

METHODS

Prospective observational study. Hyperthyroid and euthyroid cats were enrolled. Rotational thromboelastometry (ROTEM), whole-blood platelet impedance aggregometry (WBPIA) and a point-of-care viscoelastic coagulation monitor (VCM-Vet) were performed immediately after minimally traumatic venipuncture under sedation.

RESULTS

Hyperthyroid cats had significantly higher values for variables as assessed by VCM-Vet: A10 (34 [17-47] vs 25 [17-38], P = .003); A20 (39.5 [23-55] vs 31 [21-45], P = .003); and MCF (41 [24-58] vs 35 [22-49], P = .03). Hyperthyroid cats had significantly different values versus the euthyroid cohort as assessed by different ROTEM channels: increased A10, INTEM (61.5 [39-75] vs 54 [23-66], P = .007) and FIBTEM (18 [10-35] vs 13 [2-27], P = .01); increased A20, INTEM (68 [45-78] vs 61 [30-70], P = .006) and FIBTEM (17 [10-34] vs 11 [2-25], P = .002); increased MCF, EXTEM (72 [65-81] vs 69 [34-78], P = .04), INTEM (70 [45-85] vs 62 [35-71], P = .01) and FIBTEM (18 [13-37] vs 14 [3-27], P = .02); increased alpha angle, EXTEM (80 [68-85] vs 76 [41-84], P = .01); shortened CT, EXTEM (52.5 [29-73] vs 60 [52-92], P = .003) and FIBTEM (52.5 [16-75] vs 65 [53-165], P = .001); and decreased ML, FIBTEM (20 [1-36] vs 33 [19-59], P <.001). No significant differences were found with WBPIA.

CONCLUSIONS AND CLINICAL IMPORTANCE

The hyperthyroid cats in this study had evidence of altered hemostasis as assessed by 2 viscoelastic methodologies, and characterized by increased clot amplitude, firmness, and faster coagulation times vs euthyroid controls.

2024 ISFM and AAFP consensus guidelines on the long-term use of NSAIDs in cats

PRACTICAL RELEVANCE

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used and are effective for the management of pain in cats. These Guidelines will support veterinarians in decision-making around prescribing NSAIDs in situations of chronic pain, to minimise adverse effects and optimise pain management. Information is provided on mechanism of action, indications for use, screening prior to prescription, use in the presence of comorbidities, monitoring of efficacy, and avoidance and management of adverse effects.

CLINICAL CHALLENGES

The cat's unique metabolism should be considered when prescribing any medications, including NSAIDs. Chronic pain may be challenging to detect in this species and comorbidities, particularly chronic kidney disease, are common in senior cats. Management of chronic pain may be complicated by prescription of other drugs with the potential for interactions with NSAIDs.

EVIDENCE BASE

These Guidelines have been created by a panel of experts brought together by the International Society of Feline Medicine (ISFM) and American Association of Feline Practitioners (AAFP). Information is based on the available literature, expert opinion and the panel members' experience.

Body Condition Scores in Cats and Associations with Systolic Blood Pressure, Glucose Homeostasis, and Systemic Inflammation

BACKGROUND

Feline obesity is the most common nutritional disease in cats. This study aimed to investigate the differences between systolic blood pressure (SBP) and circulating concentrations of glucose, fructosamine, and serum amyloid-A (SAA) in ideal-weight, overweight, and obese cats.

METHODS

The animals were divided into three groups: ideal-weight (BCS 5, N = 20), overweight (BCS 6, N = 20), and obese cats (BCS ≥ 7, N = 20). SBP, circulating concentrations of glucose, fructosamine, and SAA were evaluated.

RESULTS

The SBP values of the ideal-weight, overweight, and obese cats were 140.0 mmHg, 160.0 mmHg, and 160.0 mmHg, respectively. The blood glucose and fructosamine levels for the ideal, overweight, and obese cats were 104.0 mg/dL and 245.0 µmol/L, 123.0 mg/dL and 289.0 µmol/L, and 133.0 mg/dL and 275.0 µmol/L, respectively, for each group. The SAA values were <5 ug/mL in all the groups. The SBP values of the cats with ideal BCS were significantly lower compared to overweight (p = 0.019) and obese (p = 0.001) cats. The blood glucose values of obese cats were higher than those of ideal-weight cats (p = 0.029). There was no statistical difference between the groups for fructosamine and SAA.

CONCLUSIONS

Obese cats had significantly higher SBP and blood glucose concentrations than ideal-weight cats, showing the effect of BSC on these parameters.

Comparison of Doppler ultrasonic sphygmomanometry, oscillometry and high-definition oscillometry for non-invasive blood pressure measurement in conscious cats

OBJECTIVES

Systemic arterial hypertension is a common occurrence and can have serious adverse consequences in cats. Therefore, measuring blood pressure is very important. There are many indirect blood pressure measurement devices available. This study compared Doppler, oscillometric (petMAP Graphic II, SunTech Vet20, the Cardell Insight-X0000) and high-definition oscillometry devices for the non-invasive measurement of blood pressure in conscious cats.

METHODS

In this prospective study, blood pressure was measured in 32 cats using the different devices according to the recommendations of the American College of Veterinary Internal Medicine Consensus Statement. Blood pressures (systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP]), time to complete measurements, number of attempts needed, coefficient of variation (CV) between the blood pressure measurements of the different devices, ease of completing measurements and apparent stress level of the cat were assessed.

RESULTS

There was a significant difference between devices in the time taken to obtain blood pressure readings and the number of attempts necessary to obtain six reliable measurements. The CV of the Doppler device was significantly smaller than that of the rest of the devices, but there were no other differences between the devices. The mean SBP, DBP and MAP measured by the petMAP device were significantly higher than the measurements from the other devices. The perceived ease of measurement was not significantly different between the various machines. The perceived level of stress of measurement with the Doppler device was significantly higher compared with the other devices but did not lead to an increased SBP.

CONCLUSIONS AND RELEVANCE

Using a Doppler device to measure blood pressure in conscious cats is fast, relatively easy and gives reliable results. A disadvantage is that the Doppler device can only measure SBP, while oscillometric devices also provide DBP and MAP. However, in veterinary medicine, systolic hypertension is considered the most relevant.

Long-term safety of dietary salt: A 5-year ProspEctive rAndomized bliNded and controlled stUdy in healThy aged cats (PEANUT study)

BACKGROUND

High-salt diets promote urine dilution and decrease urolithiasis risk.

OBJECTIVE

Prospectively evaluate the safety of chronic high dietary salt intake (randomized controlled trial).

ANIMALS

Twenty research colony neutered, healthy aged cats (11.5 years [10.0-11.6], median [interquartile range]).

METHODS

Healthy cats were randomized to control or high-salt dry diets (sodium: 1.02 ± 0.16 [mean, SD] and 3.26 ± 0.30 g/Mcal metabolizable energy [ME], respectively; chloride: 2.26 ± 0.33 and 5.71 ± 0.28 g/Mcal ME, respectively), fed for up to 60 months. Assessments included CBC, plasma biochemistry, urinalysis, glomerular filtration rate (GFR), blood pressure, renal and cardiac (conventional Doppler and 2-dimensional color tissue Doppler) imaging, annually. Cats that died or were euthanized underwent necropsy. Diet effects over time were evaluated with linear mixed models.

RESULTS

Follow-up duration (median [Interquartile range]) was similar between the control (38.7 months [28.6-48.2]) and high-salt group (51.4 months [45.7-59.0]). Diet had no significant effect on changes in GFR, blood pressure, plasma creatinine concentration, end-diastolic left ventricular (LV) wall thicknesses, LV internal diameters, LV systolic function, left atrial size, or systolic and diastolic Doppler variables. One control cat developed hypertension. One high-salt group cat developed persistent azotemia. Serial plasma biochemistry and urine specific gravity suggested early chronic kidney disease in 4 nonazotemic cats (2 per group), consistent with necropsy findings.

CONCLUSIONS AND CLINICAL IMPORTANCE

In healthy aged cats, a commercial veterinary diet containing 3.26 ± 0.30 g/Mcal ME sodium was safe with regard to renal and cardiac function for up to 5 years.

Clinical management of feline chronic kidney disease in Portugal: a questionnaire-based study

OBJECTIVES

The aim of the study was to characterise the clinical management of feline chronic kidney disease (CKD) by veterinary practitioners in Portugal.

METHODS

A questionnaire-based study was designed to be completed by all veterinarians who had diagnosed and treated at least one case of feline CKD in the previous year.

RESULTS

A total of 409 veterinary practitioners responded to the questionnaire, with approximately half of them diagnosing 2-5 cases of feline CKD per month (n = 219, 53.5%). Although a high proportion of these reported using the guidelines published by the International Renal Interest Society (n = 379, 92.7%), only 19.1% (n = 78) systematically performed systolic blood pressure (SBP) measurements in all of their patients. A renal diet was advised by almost all respondents (n = 406, 99.3%), but 36.9% (n = 150) of them considered that it represented less than 75% of the daily food intake for most of their patients. This dietary intervention was often prescribed regardless of stage (n = 298, 73.4%) and without a proper gradual diet transition. Appetite stimulants were frequently prescribed (n = 366, 89.5%), as well as a calcium channel blocker (n = 171, 41.8%) and an angiotensin-converting enzyme inhibitor (n = 245, 59.9%) to control systemic hypertension and proteinuria, respectively. Prescription of a phosphate binder was also common (n = 311, 76.0%). Regarding monitoring, 70.9% (n = 290) recommended that stable patients be reassessed every 2-3 months or more frequently, but only 35.7% (n = 146) were able to comply with this periodicity due to owners' constraints.

CONCLUSIONS AND RELEVANCE

The findings showed that although most survey respondents are aware of international guidelines for the clinical management of cats with CKD, the SBP measurement still needs to be more systematic to allow proper substaging and detection of systemic hypertension. The monitoring frequency was lower than recommended. Furthermore, the introduction of a renal therapeutic diet should be refined to improve its acceptance rate.

Cardiac Troponin I and Electrocardiographic Evaluation in Hospitalized Cats with Systemic Inflammatory Response Syndrome

Several studies conducted on humans demonstrate the increase in cardiac troponins and the onset of arrhythmias in the course of systemic inflammatory response syndrome (SIRS). The aim of the current study was to assess the blood concentration of cardiac troponin I (cTnI) and electrocardiographic findings in SIRS-affected cats. Seventeen shorthair cats hospitalized with SIRS were enrolled (Group 1). SIRS diagnosis was performed based on the detection of at least two of the four criteria such as abnormal body temperature, abnormal heart rate (i.e., tachycardia or bradycardia), abnormal respiratory rate (i.e., tachypnea or bradypnea), and alterations of white blood cell number (i.e., leukocytes or band neutrophils). Ten cats screened for elective surgery such as neutering or dental procedures were evaluated as a control population (Group 2). They were considered healthy based on history, physical examination, hematological and biochemical profile, urinalysis, coprological exam, thyroxine assay, blood pressure measurement, and echocardiography. A physical examination, complete blood cell count, biochemistry test (including an electrolyte panel), electrocardiographic examination, and cTnI assay were carried out in each cat enrolled. Traumatic events, gastrointestinal, neoplastic, respiratory, and neurological disorders were identified as causes of SIRS in Group 1. In Group 1, a significantly higher concentration of cTnI than that in Group 2 was recorded (p = 0.004). In 37.5% of cats with SIRS, ventricular premature complexes occurring in couplets with multiform configuration were detected. Similarly, to humans, data herein reported would indicate possible cardiac damage present in cats with SIRS diagnosis.

Effect of gabapentin on ambulatory, direct, systemic arterial blood pressure in apparently healthy cats in the at-home and in-clinic environments

OBJECTIVES

Situational increases in blood pressure (BP) frequently confound the accurate diagnosis of pathological systemic hypertension in cats. The objective of this study was to investigate the effect of gabapentin on direct, ambulatory systolic arterial BP (SBP) in cats in at-home and in-clinic environments.

METHODS

Six adult purpose-bred cats with surgically implanted femoral artery telemetric BP-sensing catheters were administered 100 mg of gabapentin or a placebo orally in two randomized, masked, crossover study phases. In the first, direct BP was measured continuously in undisturbed cats for 24 h before (at-home baseline) and 4 h after administration of study drug. The mean SBP after administration of the drug was compared between treatments. In the second study period, cats were administered gabapentin or placebo 90 mins before transport to a clinic, where direct BP was measured continuously during a simulated veterinary visit that included an indirect BP measurement session. Changes in mean direct SBP relative to the 24-h at-home pre-treatment period were calculated for each of one waiting room and two examination-room periods, and compared between treatments. Concurrent in-clinic direct and indirect SBP measurements were compared within-cat. Data were compared using linear mixed models.

RESULTS

Direct SBP data from one cat were excluded due to implant failure. There were no differences in at-home or in-clinic SBP between treatment groups, with large inter-individual variability. Cats in both treatment groups experienced in-clinic increases in direct SBP relative to at-home baseline (range 11-50 and 10-52 mmHg in placebo- and gabapentin-treated cats, respectively). Across all visits, direct SBP was 15.6 mmHg higher than indirect SBP (P <0.001). No effects of treatment on difference between direct and indirect SBP were identified.

CONCLUSIONS AND RELEVANCE

Significant effects of gabapentin on direct SBP were not identified, though a type II error is possible. Situational increases cannot be excluded in gabapentin-treated cats with high SBP.

Understanding the barriers to blood pressure assessment in cats

OBJECTIVES

A questionnaire was designed to survey veterinarians and veterinary nurses/technicians on blood pressure (BP) assessment in cats, including ocular examination, encompassing current methodology, indications, uptake and barriers.

METHODS

An online questionnaire was produced and promoted to more than 2000 veterinary professionals, of whom 545 answered all questions and 85 answered most questions.

RESULTS

Of the participants, 572 (90.8%) were based in the UK and almost all (n = 613, 97.3%) had access to a BP monitor. Of those that had a monitor, most (n = 550, 88.4%) participants had access to a Doppler monitor; 367 (59.0%) participants had access to multiparameter monitors; fewer (n = 202, 32.5%) had access to oscillometric BP monitors. Where applicable, Doppler monitors were most commonly chosen for conscious cat measurements (n = 337, 72.2%) due to the greater 'trust' and 'reliability' of these compared with oscillometric machines. Conscious BP measurement typically involved two members of staff (n = 391, 62.9%). Only 156 (29.1%) participants recommended BP assessment at least several times a week in their interactions with cat owners. BP assessment was routinely recommended in cats with ocular target organ damage (n = 365, 87.7%), chronic kidney disease (n = 346, 78.6%), proteinuria (n = 255, 63.0%) and hyperthyroidism (n = 266, 60.9%). Common equipment-related barriers included 'cuff frustration' and difficulties hearing the pulse signal for Doppler users (72.2% and 71.6%, respectively), and oscillometric machines failing to give a reading at least some of the time (52.8%). Situational hypertension concerns affected many (n = 507, 92.0%), as did lack of time to do the procedure (n = 402, 73.0%). Significant owner barriers included difficulties persuading the owner to bring their cat in for BP checks (n = 475, 86.2%) and concerns over costs (n = 445, 80.8%). Most participants had access to a direct ophthalmoscope (n = 527, 96.5%); however, 399 (73.1%) reported that they struggled to interpret ocular findings.

CONCLUSIONS AND RELEVANCE

Significant barriers exist to successful BP assessment in cats. Education and support of clinics should focus on improving confidence with equipment and eye examination.

Prevalence of persistent hypertension and situational hypertension in a population of elderly cats in The Netherlands

OBJECTIVES

Systemic arterial hypertension is increasingly recognised and can have serious adverse consequences in cats. Unfortunately, the act of measuring blood pressure itself may cause an increase in blood pressure, known as situational hypertension. It is currently unknown how often this phenomenon occurs. The aim of this study was to evaluate the prevalence of persistent hypertension and situational hypertension in an elderly population of cats in a first-opinion clinic and to assess which factors were associated with systolic hypertension.

METHODS

In this prospective study, systolic blood pressure was measured in 185 cats aged ⩾10 years using the Doppler sphygmomanometry method according to the recommendations of the American College of Veterinary Internal Medicine consensus statement. Age, sex, body weight, body condition score, position during blood pressure measurement and apparent stress level were assessed. If a systolic blood pressure >160 mmHg was found, measurements were repeated to evaluate if persistent hypertension or situational hypertension was present. The first set of blood pressure measurements were used for all the statistical analyses.

RESULTS

The median systolic blood pressure for this population was 140 mmHg. The prevalence of persistent hypertension was at least 14.6% and situational hypertension at least 5.4%. Factors significantly associated with hypertension were age, higher apparent stress levels and a sitting position during measurement. Sex, body weight or body condition score did not significantly influence systolic blood pressure.

CONCLUSIONS AND RELEVANCE

Both persistent hypertension and situational hypertension are common in elderly cats. There are no reliable parameters to distinguish between the two, underlining the importance of a standard protocol and repeating measurements during a follow-up visit when hypertension is found. Age, demeanour and body position during blood pressure measurement influenced blood pressure in this population of elderly cats.

Chemical immobilisation of lions: weighing up drug effectiveness versus clinical effects

Selection of an effective drug combination to immobilise African lions (Panthera leo) requires balancing immobilisation effectiveness with potential side effects. We compared the immobilisation effectiveness and changes to physiological variables induced by three drug combinations used for free-ranging African lions. The lions (12 animals per drug combination) were immobilised with tiletamine-zolazepam-medetomidine (TZM), ketamine-medetomidine (KM) or ketamine-butorphanol-medetomidine (KBM). Induction, immobilisation, and recovery were timed, evaluated using a scoring system, and physiological variables were monitored. The drugs used for immobilisation were antagonised with atipamezole and naltrexone. The quality of induction was rated as excellent for all drug combinations and induction times (mean ± SD) did not differ between the groups (10.54 ± 2.67 min for TZM, 10.49 ± 2.63 min for KM, and 11.11 ± 2.91 min for KBM). Immobilisation depth was similar over the immobilisation period in the TZM and KBM groups, and initially light, progressing to deeper in lions administered KM. Heart rate, respiratory rate and peripheral arterial haemoglobin saturation with oxygen were within the expected range for healthy, awake lions in all groups. All lions were severely hypertensive and hyperthermic throughout the immobilisation. Following antagonism of immobilising drugs, lions immobilised with KM and KBM recovered to walking sooner than those immobilised with TZM, at 15.29 ± 10.68 min, 10.88 ± 4.29 min and 29.73 ± 14.46 min, respectively. Only one lion in the KBM group exhibited ataxia during recovery compared to five and four lions in the TZM and KM groups, respectively. All three drug combinations provided smooth inductions and effective immobilisations but resulted in hypertension. KBM had an advantage of allowing for shorter, less ataxic recoveries.

Evaluation of cardiac troponin I as a predictor of death in critically ill cats

BACKGROUND

Abnormally high serum cardiac troponin I (cTnI) concentration, reflecting leakage from or necrosis of cardiomyocytes, is a negative prognosticator for death in dogs.

OBJECTIVES

To investigate in critically ill cats whether serum cTnI concentration is abnormally high, identify conditions associated with abnormally high cTnI concentrations, and evaluate cTnI as an independent prognosticator for death and a potential coprognosticator to the acute patient physiologic and laboratory evaluation (APPLE) score in cats.

ANIMALS

One hundred nineteen cats admitted to intensive care units (ICU) and 13 healthy cats at 2 university teaching hospitals.

METHODS

Prospective study. Clinical examinations were performed, APPLE scores calculated, and serum cTnI and serum amyloid A (SAA) measured within 24 hours after admission. Outcome was defined as death/euthanasia or survival to discharge, 28 and 90 days after ICU-admission. Prognostic capacity of cTnI, APPLE scores and models combining cTnI and scores were evaluated by receiver-operator-characteristic analyses.

RESULTS

Median (IQR) serum cTnI concentration was higher in ill (0.63 [0.18-2.65] ng/mL) compared to healthy (0.015 [0.005-0.041] ng/mL) cats (P < .001) and higher in subgroups with structural cardiac disease (2.05 [0.54-16.59] ng/mL; P < .001) or SAA >5 mg/L (0.84 [0.23-2.81] ng/mL; P = .009) than in cats without these characteristics (0.45 [0.12-1.70] and 0.35 [0.015-0.96] ng/mL). The in-hospital case fatality rate was 29%. Neither serum cTnI concentration for all critically ill cats (area-under-the-curve 0.567 [95% CI 0.454-0.680], n = 119) or subgroups (0.625 [0.387-0.863], n = 27; 0.506 [0.360-0.652], n = 86), nor APPLE scores (fast 0.568 [0.453-0.682], full 0.585 [0.470-0.699], n = 100), were significant prognosticators for death.

CONCLUSIONS AND CLINICAL IMPORTANCE

Abnormally high serum cTnI concentration was common in critically ill cats. Unlike in dogs, cTnI did not confer prognostic information regarding death.

Comparison of the cardiovascular effects of immobilization with three different drug combinations in free-ranging African lions

Thirty-six free-ranging lions (12 per group) were immobilized with tiletamine-zolazepam (Zoletil 0.6 mg/kg i.m.) plus medetomidine (0.036 mg/kg i.m.) (TZM), ketamine (3.0 mg/kg i.m.) plus medetomidine (0.036 mg/kg i.m.) (KM) or ketamine (1.2 mg/kg i.m.) plus butorphanol (0.24 mg/kg i.m.) plus medetomidine (0.036 mg/kg i.m.) (KBM). During immobilization cardiovascular variables were monitored at 5-minute intervals for a period of 30 minutes. Lions immobilized with all three drug combinations were severely hypertensive. Systolic arterial pressure was higher at initial sampling in lions immobilized with KM (237.3 ± 24.8 mmHg) than in those immobilized with TZM (221.0 ± 18.1 mmHg) or KBM (226.0 ± 20.6 mmHg) and decreased to 205.8 ± 19.4, 197.7 ± 23.7 and 196.3 ± 17.7 mmHg, respectively. Heart rates were within normal ranges for healthy, awake lions and decreased throughout the immobilization regardless of drug combination used. Lions immobilized with TZM had a higher occurrence (66%) of skipped heart beats than those immobilized with KBM (25%). The three drug combinations all caused negative cardiovascular effects, which were less when KBM was used, but adverse enough to warrant further investigations to determine if these effects can be reversed or prevented when these three combinations are used to immobilize free-living lions.

Feline Stress Management During air Travel: A Multimodal Approach

PRACTICAL RELEVANCE

More cats are travelling by air every year; however, air travel involves several common causes of stress for cats, such as environmental changes and a lack of control and predictability. The use of a multimodal stress management protocol for all stages of the relocation process, including appropriate and effective anxiolytic medication where necessary, is therefore important in order to safeguard the cat's welfare while travelling.

CLINICAL CHALLENGES

Cats may be presented to veterinarians for the purpose of preparing them and/or their documentation for air travel. Maintaining and protecting a cat's physical, mental and emotional health in a stressful environment, while subjected to likely unfamiliar sights, noises, smells and the movement of the aircraft, and additionally dealing with international legislation, regulations and documents, can pose a complex challenge to veterinarians.

AIMS

This review describes the importance of stress management during air travel for cats, aims to raise awareness about the often poorly understood challenges involved, and outlines effective and airline-compliant stress management modalities. While the discussion is focused on air travel specifically, the stress management methods described can be applied to all types of longer distance travel, such as a long road trip or a ferry crossing, as well as a stay in a holiday home.

EVIDENCE BASE

There are currently no studies specifically on air travel in cats and, similarly, there are also limited data on air travel in other species. Many of the recommendations made in this review are therefore based on the authors' extensive experience of preparing pets for travel, supported by published data when available.

Caudal vena cava measurements and fluid responsiveness in hospitalized cats with compromised hemodynamics and tissue hypoperfusion

OBJECTIVE

To evaluate the use of the caudal vena cava collapsibility index (CVCCI) and the inspiratory/minimum and expiratory/maximum diameters of the vena cava to predict fluid responsiveness in hospitalized, critically ill cats with hemodynamic and tissue perfusion abnormalities.

DESIGN

Diagnostic test study in a prospective cohort of hospitalized cats.

SETTING

Private practice referral hospital.

ANIMALS

Twenty-four hospitalized cats with spontaneous breathing and compromised hemodynamics and tissue hypoperfusion.

INTERVENTIONS

Ultrasonographic examination before and after fluid expansion with 10 ml/kg of lactated Ringer's solution.

MEASUREMENTS AND MAIN RESULTS

Fluid responsiveness was evaluated using the velocity-time integral (VTI) of the subaortic blood flow, by measuring it before and after a fluid load of 10 ml/kg of lactated Ringer's solution. The CVCCI was calculated using the following formula: (maximum diameter - minimum diameter / maximum diameter) × 100. Ten cats were fluid responders (42 %) and 14 were nonresponders (58 %). The area under the receiver operating characteristic curve (AUROC) with their 95% confidence interval for the predictors and the best cutoff values were as follows: CVCCI, AUROC = 0.83 (0.66-1.00) and cutoff = 31%; inspiratory/minimum diameter, AUROC = 0.86 (0.70-1.00) and cutoff = 0.24 cm; expiratory/maximum diameter, AUROC = 0.88 (0.74-1.00) and cutoff = 0.22 cm. A significant lineal correlation was observed between the percentage of increase in VTI after expansion and CVCCI (r_s  = 0.68, P < 0.001), expiratory/maximum diameter (r_s  = -0.72, P < 0.001), and inspiratory/minimum diameter (r_s  = -0.71, P < 0.001). The intraobserver and interobserver variability was low for VTI, and the expiratory/maximum diameter and inspiratory/minimum diameter were high for CVCCI.

CONCLUSIONS

Caudal vena cava measurements could be useful to predict the response to fluids in hospitalized cats with hemodynamic and tissue perfusion alterations. Additional studies are required to draw definitive conclusions about the role of these variables to guide fluid administration in cats.

Repurposing Drugs in Small Animal Oncology

Repurposing drugs in oncology consists of using off-label drugs that are licensed for various non-oncological medical conditions to treat cancer. Repurposing drugs has the advantage of using drugs that are already commercialized, with known mechanisms of action, proven safety profiles, and known toxicology, pharmacokinetics and pharmacodynamics, and posology. These drugs are usually cheaper than new anti-cancer drugs and thus more affordable, even in low-income countries. The interest in repurposed anti-cancer drugs has led to numerous in vivo and in vitro studies, with some promising results. Some randomized clinical trials have also been performed in humans, with certain drugs showing some degree of clinical efficacy, but the true clinical benefit for most of these drugs remains unknown. Repurposing drugs in veterinary oncology is a very new concept and only a few studies have been published so far. In this review, we summarize both the benefits and challenges of using repurposed anti-cancer drugs; we report and discuss the most relevant studies that have been previously published in small animal oncology, and we suggest potential drugs that could be clinically investigated for anti-cancer treatment in dogs and cats.

Evaluation of the effects of gabapentin on the physiologic and echocardiographic variables of healthy cats: a prospective, randomized and blinded study

OBJECTIVES

The aim of this study was to evaluate, using echocardiography, the effects of oral administration of a single dose of gabapentin on the physiologic variables (heart rate [HR], respiratory rate [RR] and systolic blood pressure [SBP]) and systolic and diastolic cardiac function of healthy cats.

METHODS

This was a prospective, randomized and blinded study with 40 healthy cats aged between 6 months and 2 years. The cats' health status was assessed on the first appointment (T1) when they underwent a physical examination, complete blood count, biochemical profile, assessment of physiologic variables and echocardiogram. The echocardiogram was used to measure the left ventricle's (LV) internal diameter during systole and diastole, isovolumic relaxation time, transmitral flow, E-wave deceleration time and HR. The cats were randomly divided into two groups: (1) a treatment group with 20 cats that received a single oral dose of gabapentin (100 mg/cat); and (2) a control group with 20 cats that received a single oral dose of placebo. All variables of the physiologic and echocardiographic variables were re-evaluated 1-3 weeks after T1 (T2), 90 mins after medication or placebo administration.

RESULTS

There was no difference in the physiologic variables evaluated in both groups. The proportion of cats in the treatment group that had their ventricular filling waves fused on T1 but did not have them fused on T2 was significantly higher (45%) compared with cats in the control group (15%; P = 0.0384).

CONCLUSIONS AND RELEVANCE

There was no difference between the groups in regard to SBP, HR, RR and echocardiographic variables. Gabapentin improved evaluation of diastolic function on echocardiogram because it reduced the fusion of ventricular filling waves during the evaluation of the diastolic function of the LV. Gabapentin did not cause adverse effects on the cardiovascular hemodynamics of young healthy cats.

Cross-sectional survey of non-invasive indirect blood pressure measurement practices in cats by veterinarians

OBJECTIVES

This survey of small animal veterinarians endeavored to: (1) determine current methods of indirect blood pressure measurement; (2) detail techniques used to reduce situational hypertension; and (3) better understand the obstacles to performing blood pressure measurement in cats.

METHODS

An online survey was produced and circulated to members of the Veterinary Information Network. A total of 733 veterinarians who saw cats in their practice and had access to at least one indirect blood pressure device completed the entirety of the survey.

RESULTS

Ninety-six percent (703/733) of veterinarians who completed the survey reported measuring indirect blood pressure in cats in their practice, with veterinary technicians conducting most (600/703; 85.3%) of these measurements. Few veterinarians (30/733; 4.1%) did not measure blood pressure, with these veterinarians citing several obstacles including: difficulty interpreting results with the occurrence of fear, anxiety and stress in cats (20/30; 66.7%); difficulty performing measurements in cats (17/30; 56.7%); and technical staff being uncomfortable performing measurements (12/30; 40.0%). Most veterinarians (300/435; 69.0%) in this survey preferred an ultrasonic Doppler flow detector with sphygmomanometry, with many (272/300; 90.7%) perceiving that the results obtained with this device were more trustworthy compared with results obtained with oscillometry. Ninety percent (633/703) of veterinarians employed techniques to reduce situational hypertension in cats. Techniques perceived to be most helpful among veterinarians included: using a quiet location (454/633; 71.7%); minimizing restraint (316/633; 49.9%); performing blood pressure prior to other procedures (eg, phlebotomy, cystocentesis) (302/633; 47.7%); avoiding other animals (219/633; 34.6%); and allowing time for acclimation (167/633; 26.4%).

CONCLUSIONS AND RELEVANCE

This survey study of veterinarians helps clarify obstacles to routine blood pressure measurement in conscious cats. Veterinarians reported several strategies that they felt reduced situational hypertension in cats. The data inform modifications of techniques to increase the frequency and perceived reliability of blood pressure measurement in at-risk cats.

2022 ISFM/AAFP Cat Friendly Veterinary Environment Guidelines

PRACTICAL RELEVANCE

The '2022 ISFM/AAFP Cat Friendly Veterinary Environment Guidelines' (hereafter the 'Cat Friendly Veterinary Environment Guidelines') describe how the veterinary clinic environment can be manipulated to minimise feline patient distress. Many components of a veterinary clinic visit or stay may result in negative experiences for cats. However, much can be done to improve a cat's experience by making the veterinary clinic more cat friendly. Exposure to other cats and other species can be reduced, and adjustments made with consideration of the feline senses and species-specific behaviour. Caregivers can prepare cats for a clinic visit with appropriate advice. Waiting rooms, examination rooms, hospital wards and other clinic areas can be designed and altered to reduce stress and hence encourage positive emotions. Changes need not be structural or expensive in order to be effective and make a difference to the cats and, in turn, to cat caregivers and the veterinary team. Moreover, by improving the all-round experience at the veterinary clinic, there are positive effects on preventive healthcare, identification of and recovery from illness, and compliance with treatment.

CLINICAL CHALLENGES

Good feline healthcare necessitates visiting the veterinary clinic, which, simply by being outside of a cat's territory and familiar surroundings, may lead to negative experiences. Such experiences can trigger negative (protective) emotions and associated physiological stress, which can result in misleading clinical findings, patient distress, prolonged recovery from illness, further difficulties with handling at subsequent visits and potential veterinary personnel injury. There may be a mistaken belief that veterinary clinics must undergo significant renovation or building work to become cat friendly, and that, if species cannot be separated, then clinics cannot improve their care of cats. These Guidelines aim to dispel any such misconceptions and provide detailed practical advice.

EVIDENCE BASE

These Guidelines have been created by a Task Force of experts convened by the International Society of Feline Medicine and American Association of Feline Practitioners, based on an extensive literature review and, where evidence is lacking, the authors' experience. Endorsements: These Guidelines have been endorsed by a number of groups and organisations, as detailed on page 1161 and at icatcare.org/cat-friendly-guidelines and catvets.com/environment.

2022 AAFP/ISFM Cat Friendly Veterinary Interaction Guidelines: Approach and Handling Techniques

PRACTICAL RELEVANCE

The '2022 AAFP/ISFM Cat Friendly Veterinary Interaction Guidelines: Approach and Handling Techniques' (hereafter the 'Cat Friendly Veterinary Interaction Guidelines') support veterinary professionals with feline interactions and handling to reduce the impact of fear and other protective (negative) emotions, in so doing enhancing feline welfare and In implementing these Guidelines, team satisfaction and cat caregiver confidence in the veterinary team will increase as the result of efficient examinations, better experience, more reliable diagnostic testing and improved feline wellbeing. Veterinary professionals will learn the importance of understanding and appropriately responding to the current emotional state of the cat and tailoring each visit to the individual.

CLINICAL CHALLENGES

Cats have evolved with emotions and behaviors that are necessary for their survival as both a predator and prey species. A clinical setting and the required examinations and procedures to meet their physical health needs can result in behavioral responses to protective emotions. Cat friendly interactions require understanding, interpreting and appropriately responding to cats' emotional states and giving them a perceived sense of control while performing the required assessment.

EVIDENCE BASE

These Guidelines have been created by a Task Force of experts convened by the American Association of Feline Practitioners and the International Society of Feline Medicine, based on an extensive literature review and, where evidence is lacking, the authors' experience.

ENDORSEMENTS

These Guidelines have been endorsed by a number of groups and organizations, as detailed on page 1127 and at catvets.com/interactions and icatcare.org/cat-friendly-guidelines.

'The Mercury Challenge': feline systolic blood pressure in primary care practice - a European survey

OBJECTIVES

The aim of this study was to collect data from a substantial number of older cats having their systolic blood pressure (SBP) measured in a variety of clinical practices, to describe the findings and assess variables that affected the duration of assessment and the values obtained.

METHODS

An international (European-based) multicentre convenience sample survey of cats ⩾7 years of age attending veterinary clinics and having SBP measured as part of their clinical assessment. Information gathered included details of the cat, concomitant disease(s) or therapies, SBP results, device used, time taken to assess SBP and the demeanor of the cat.

RESULTS

Useable data were available from 8884 cats aged 7-26 years, from 811 clinics across 16 countries. The device used to measure SBP was Doppler in 47.4% and oscillometry in 48.5%. The demeanor of the cat was reported to be calm in 45.7%, anxious in 41.9% and nervous in 8.9%; and the duration of assessment was reported to be <5 mins in 50.4%, 5-10 minutes in 41.7% and >10 mins in 7.9%. Concomitant chronic kidney disease (CKD) was reported in 21.8%, hyperthyroidism in 12.0% or both in 3.1%. The median SBP was 150 mmHg (range 80-310), with 18.6% classified as hypertensive (SBP 160-179 mmHg) and 21.1% as severely hypertensive (SBP ⩾180 mmHg). The measured SBP was significantly affected by the cat's demeanor, duration of SBP assessment, presence of CKD and/or hyperthyroidism, the cat's sex and age, and the presence of concomitant therapy. The duration of SBP assessment was significantly affected by the cat's demeanor.

CONCLUSIONS AND RELEVANCE

In veterinary clinics, SBP can be measured in most cats within a short period of time using either Doppler or oscillometric equipment. The presence of CKD or hyperthyroidism was associated with significantly higher SBP values, and anxious or nervous cats had higher SBP values and took longer to obtain SBP assessments.

Feline Comorbidities: Balancing hyperthyroidism and concurrent chronic kidney disease

PRACTICAL RELEVANCE

Both hyperthyroidism and chronic kidney disease (CKD) are common long-term conditions in older cats, which might be diagnosed concurrently or develop at different times. Hyperthyroidism may mask the presence of CKD, and vice versa, by various mechanisms that are described in this review. Hyperthyroidism treatment options should be carefully considered when CKD has also been diagnosed.

CLINICAL CHALLENGES

Although it can be difficult to diagnose hyperthyroidism and CKD simultaneously, given that one condition may mask the other, it is important to consider the presence of both diseases when examining an older cat presenting with vomiting, weight loss, polyuria/ polydipsia, anorexia or sarcopenia. The concurrent presence of hyperthyroidism and CKD requires careful monitoring of glomerular filtration rate biomarkers, and adequate and prompt support of kidney function when normal thyroid function is re-established. Iatrogenic hypothyroidism is a recognised complication of all of the treatment options for hyperthyroidism, and increases the risk of azotaemia. Therapy with levothyroxine is recommended for cats that are hypothyroid and azotaemic.

EVIDENCE BASE

The information in this review draws on current literature and guidelines related to the pathophysiology, diagnosis and treatment recommendations for feline hyperthyroidism and CKD.

Use of a human wrist blood pressure monitor for arterial blood pressure measurements in normotensive conscious dogs in comparison to veterinary high-definition oscillometry

Background

The gold standard in canine blood pressure (BP) measurement is the invasive method; however, non‐invasive blood pressure measurement techniques (NIBP) are more commonly used. The lack of small, lightweight, cheap, fast and portable NIBP still remains a point to improve in the emergency setting.

Key Findings

A human wrist blood pressure (WBP) device was evaluated in comparison with the veterinary high‐definition oscillometry (HDO) in conscious normotensive dogs. Systolic and diastolic BPs were evaluated in two groups of dogs. The bias, the limits of agreement and correlation between variables were calculated. Twenty‐five and 36 dogs were, respectively, included in Study No. 1 (dogs weighting ≥10 kg) and 2 (dogs weighting ≥20 kg). In both studies, correlation between the two devices was moderate. A better agreement was displayed for diastolic pressure and poor precision for both systolic and diastolic pressures measurements (as determined by wide limits of agreement). The WBP method underestimated both the systolic and diastolic BP with respect to the HDO method. The inclusion of bigger dogs (Study No. 2) with limb circumference more like to human limb dimension did not improve the agreement between considered methods.

Significance

The human WBP monitor considered is not suitable to replace the commonly used veterinary HDO for in‐clinic BP monitoring in normotensive conscious dogs.

Aging in Cats: Owner Observations and Clinical Finding in 206 Mature Cats at Enrolment to the Cat Prospective Aging and Welfare Study

Two hundred and six cats, aged between 7 and 10 years, from the North-west of the UK, were enrolled in a cat aging and welfare study to determine the frequency of age-related conditions and associations with husbandry, owner observations of physical appearance, activity and behavior. This is the largest study to date of mature cats that includes data from an owner questionnaire and clinical examinations. At enrolment, owners frequently reported physical changes (53%), behavioral changes (47%), changes to eating patterns (41%), and activity changes (40%) in their mature cats. On physical examination, 45% cats were in overweight condition and 12% were obese. A heart murmur was detected in 29% cats, whilst indirect systolic blood pressure (SBP) was >160 mmHg in 5% cats. Dental disease was present in 54% cats and was associated with a matted hair coat (P = 0.01), increased sleeping (P = 0.02), absence of gray hairs (P = 0.03), and increased irritability to other pets (P = 0.04). Abnormalities were evident in 58% of cats that allowed an orthopedic examination (OE) to be performed. These cats were older than cats with a normal OE (P = 0.01), and abnormal OE findings were associated with a matted coat (P = 0.03) and increased grooming (P = 0.04). Aazotaemia was present in 10% cats, and this was associated with cats being observed to “sniff their food and then walk away” (P = 0.04). Hyperthyroidism was diagnosed in 3% cats, who were older (P = 0.02), had a leaner BCS (P = 0.02) and lesser blood creatinine concentrations (P = 0.01). Hyperthyroid cats were also more likely to have increased liver enzyme activity and increased SBP (P = <0.001) compared with non-hyperthyroid cats. Of the 176 cats where all clinical assessments were conducted, only 12% had no evidence of any disease. Clinical abnormalities are commonly identified when thorough, clinical assessments are performed in mature pet cats visiting primary care practice.

Circulating renin‐angiotensin‐aldosterone system activity in cats with systemic hypertension or cardiomyopathy

Background

Activity of the circulating renin‐angiotensin‐aldosterone system (RAAS) has not been comprehensively characterized in cats with systemic hypertension (SH) or cardiomyopathy (CM), and the effects of furosemide or amlodipine treatment on the RAAS have not been fully evaluated in cats.

Hypothesis/Objectives

To document RAAS activity in cats with SH or CM compared to healthy cats and determine how RAAS profiles change with furosemide or amlodipine treatment.

Animals

Sixty‐six client‐owned cats: 15 with SH (7 amlodipine‐treated, 8 untreated), 17 with advanced CM (7 furosemide‐treated, 10 not furosemide‐treated), and 34 healthy cats.

Methods

Equilibrium concentrations of RAAS peptides and aldosterone were quantified in serum samples by liquid chromatography‐mass spectrometry. Variables were compared between groups using Kruskal‐Wallis analysis with post hoc Holms‐corrected Dunn's testing.

Results

Compared with healthy cats, cats with CM had higher concentrations of angiotensin I, aldosterone, and plasma renin activity (all P < .01), and these differences remained significant (P < .03) after considering subgroups of untreated or furosemide‐treated cats. Compared with healthy cats, untreated cats with SH showed no differences in RAAS biomarkers, whereas amlodipine‐treated cats had higher concentrations of angiotensins I, II, III, IV, and 1‐7, aldosterone, and plasma renin activity (all P < .03). Multivariable analysis determined that furosemide and amlodipine treatments were independent predictors of increased RAAS biomarker concentrations.

Conclusions and Clinical Importance

Cats with CM had increased RAAS activity, whereas cats with untreated SH did not. Furosemide and amlodipine both led to nonspecific activation of both classical and alternative RAAS pathways in cats.

Drug-Dosing Adjustment in Dogs and Cats with Chronic Kidney Disease

Chronic kidney disease is a common kidney disorder in adult and aged dogs and cats; the management of associated complications and comorbidities generally requires a life-long medical treatment to ensure a good quality of life of affected patients. However, indications and the literature on drug dosing in dogs and cats with chronic kidney disease are often lacking. The aim of this review is to revise the current literature on drug dosing in canine and feline patients with renal impairment, with a special focus on the most commonly used medications to manage chronic kidney disease and possible comorbidities.

Natural history of hypertrophic cardiomyopathy in cats from rehoming centers: The CatScan II study

BACKGROUND

The natural history of hypertrophic cardiomyopathy (HCM) in cats has been mainly studied in cats referred for suspected heart disease, which can skew the results towards cats with clinical signs. Few data are available on factors associated with development of HCM in cats.

HYPOTHESES

(1) Clinical variables can predict which cats will develop HCM; (2) HCM in cats not referred for suspected heart disease is associated with a low rate of cardiovascular events.

ANIMALS

One hundred seven cats from rehoming centers without a history of clinical signs of cardiac or systemic disease at the time of adoption.

METHODS

Prospective longitudinal study. After rehoming, shelter cats were reexamined for serial echocardiograms. Cox regression analysis was used to identify predictors of development of HCM in cats that were normal at baseline. Adverse cardiovascular events including heart failure, thromboembolism, or sudden death were recorded.

RESULTS

Cats were monitored for a median of 5.6 [1.2-9.2] years. At baseline, 68/107 cats were normal, 18/107 were equivocal and 21/107 had HCM. Nineteen cats developed HCM during the study period. The factors at baseline associated with increased hazard of developing HCM were lower left atrial fractional shortening, higher left ventricular fractional shortening, and higher body weight. Cardiovascular events were observed in 21% of cats with HCM.

CONCLUSIONS AND CLINICAL IMPORTANCE

Cardiovascular events were common in cats with HCM from a rehoming center study sample. Lower left atrial systolic function appears to precede overt HCM.

Reliability of detecting fundus abnormalities associated with systemic hypertension in cats assessed by veterinarians with and without ophthalmology specialty training

OBJECTIVES

Systemic hypertension (SHT) causes severe target organ damage (TOD) and blood pressure (BP) measurement should be routine in at-risk populations. Fundoscopy is a tool to corroborate acute clinical relevance of high BP results and to decide on immediate therapy. Not every cat with a high BP result can be examined by an ophthalmologist. The study objective was to determine the reliability of fundoscopy in cats with SHT performed by a veterinarian without ophthalmology specialty training.

METHODS

Cats with suspicion of hypertensive TOD or belonging to an at-risk population for SHT with a first measurement of elevated BP >160 mmHg were enrolled. Indirect ophthalmoscopy was performed by a recent graduate veterinarian followed by a veterinary ophthalmologist. Confirmation of SHT was based on two additional sets of systolic BP measurements >160 mmHg by Doppler sphygmomanometry.

RESULTS

Thirty-three cats were included. SHT was confirmed in 27 cats. SHT was detected on routine examinations in 12/27 cats; fundoscopic lesions were observed in 9/12 by the non-trained veterinarian and in 11/12 by an ophthalmologist. Nine of 27 cats were neurological patients; fundoscopic lesions were detected in 4/9 by the non-trained veterinarian and in 7/9 by an ophthalmologist. Six of 27 cats were presented for acute blindness; fundus lesions were detected in all six cats by the non-trained veterinarian and ophthalmologist. SHT was not confirmed and fundoscopic lesions were not detected by either examiner in 6/33 cats. Compared with a veterinary ophthalmologist, reliability of detecting fundus abnormalities by the non-trained veterinarian was 72% (13/18) for cats with, and 100% (6/6) for cats without, vision.

CONCLUSIONS AND RELEVANCE

Fundus examination by a non-specialty trained veterinarian has reasonably high reliability for the detection of ocular TOD. Private practice veterinarians are encouraged to perform an initial fundic examination in suspected hypertensive cats.

Management of Feline Hyperthyroidism and the Need to Prevent Oxidative Stress: What Can We Learn from Human Research?

Feline hyperthyroidism is a clinical syndrome related to an excessive production of thyroid hormones, and it is considered as a spontaneous animal model for human thyrotoxicosis. Many shared features between the feline and the human disease have been identified so far, including pathogenesis, clinical signs, and treatment options. Although methimazole is considered the first-choice drug in both species, several side effects have been described. Furthermore, methimazole could interfere with the oxidative status, already perturbated by the disease. It has been reported in humans that dietary management, mainly through antioxidant supplementation, could mitigate this oxidative burden. The purpose of the review is to describe current therapeutic options in the course of feline hyperthyroidism and to summarize the state of the art relationship between dietary antioxidants administration and the reduction of methimazole side-effects in humans to support the use of this approach also in cats.

Evaluation of coccygeal and radial artery Doppler blood pressure measurements in sick cats with and without abnormalities in tissue perfusion

OBJECTIVE

To compare systolic blood pressure measured by Doppler (SBP) taken from the coccygeal artery versus common digital branch of the radial artery in cats with normal and poor perfusion parameters.

DESIGN

Prospective, observational study.

SETTING

University Teaching Hospital.

ANIMALS

Eighty-five cats presenting to the emergency service for which prior emergency treatment was not received and a blood pressure was indicated on triage.

INTERVENTIONS

Systolic blood pressure was measured by Doppler using the radial and coccygeal arteries. Cats were categorized as having normal or poor tissue perfusion based on physical examination.

MEASUREMENTS AND MAIN RESULTS

Agreement was poor between coccygeal and radial SBP overall with absolute and relative bias (95% limits of agreement) of 23 (-51 to 96) mm Hg and 16% (-38% to 69%), respectively. In cats with poor perfusion, the agreement was absolute bias = 28 mm Hg and relative bias = 22% and with normal perfusion absolute bias = 22 mm Hg, and relative bias = 12%. The median (interquartile range) coccygeal SBP was significantly different from the radial SBP 141 (50) mm Hg versus 120 (45) mm Hg, P < 0.001. In multivariate linear regression, heart rate was negatively associated with coccygeal SBP (r²  = 0.088, P = 0.049), and pale mucous membrane color (P = 0.034) and poor pulse quality (P = 0.007) were independently associated with lower radial SBP (r²  = 0.18).

CONCLUSIONS

Median coccygeal SBP is significantly greater than radial SBP in sick cats with both normal perfusion and hypoperfusion. Agreement between coccygeal and radial SBP is poor in cats and cannot be used interchangeably. As clinically significant differences exist between sites, the authors recommend obtaining SBP from both sites initially and choosing to monitor and trend changes with the one site that correlates most with physical examination findings.

2021 AAFP Feline Senior Care Guidelines

The '2021 AAFP Feline Senior Care Guidelines' are authored by a Task Force of experts in feline clinical medicine and serve as an update and extension of those published in 2009. They emphasize the individual patient evaluation and the process of aging, with references to other feline practice guidelines for a more complete discussion of specific diseases. Focusing on each cat encourages and empowers the owner to become a part of the cat's care every step of the way. A comprehensive discussion during the physical examination and history taking allows for tailoring the approach to both the cat and the family involved in the care. Videos and analysis of serial historical measurements are brought into the assessment of each patient. These Guidelines introduce the emerging concept of frailty, with a description and methods of its incorporation into the senior cat assessment. Minimum database diagnostics are discussed, along with recommendations for additional investigative considerations. For example, blood pressure assessment is included as a minimum diagnostic procedure in both apparently healthy and ill cats. Cats age at a much faster rate than humans, so practical timelines for testing frequency are included and suggest an increased frequency of diagnostics with advancing age. The importance of nutrition, as well as senior cat nutritional needs and deficiencies, is considered. Pain is highlighted as its own syndrome, with an emphasis on consideration in every senior cat. The Task Force discusses anesthesia, along with strategies to allow aging cats to be safely anesthetized well into their senior years. The medical concept of quality of life is addressed with the latest information available in veterinary medicine. This includes end of life considerations like palliative and hospice care, as well as recommendations on the establishment of 'budgets of care', which greatly influence what can be done for the individual cat. Acknowledgement is given that each cat owner will be different in this regard; and establishing what is reasonable and practical for the individual owner is important. A discussion on euthanasia offers some recommendations to help the owner make a decision that reflects the best interests of the individual cat.

Kidney function and glucose metabolism in overweight and obese cats

Background: In people, obesity and prediabetes mellitus might predispose to chronic kidney disease (CKD).Aims: To assess the association of overweight [Body condition score (BCS) >5] and glucose metabolism alterations, with established or potential markers of CKD. In addition, fructosamine and fasted blood glucose were compared as predictors of early abnormal glucose metabolism.Methods: 54 clinically healthy cats were included in a cross-sectional study comprising 25 neutered males and 29 (28 neutered) females aged 7.2 (5.5-9.4) years. Two potential markers of CKD, namely urinary free active transforming growth factor-β1-creatinine ratio and urinary retinol binding protein-creatinine ratio were measured along with other parameters to assess CKD. A receiver operating curve was used to identify the best sensitivity and specificity of fructosamine to identify cats with fasting glucose >6.5 mmol/L.Results: No association was found between BCS and markers of CKD. Fructosamine was greater in cats with fasting glucose >6.5 mmol/L compared to those with fasting glucose ≤6.5 mmol/L. A fructosamine concentration ≥250 µmol/L was able to detect cats with hyperglycemia with a sensitivity of 77% and a specificity of 65%. Furthermore, fructosamine was more strongly correlated with fasting glucose than albumin-corrected fructosamine (r = 0.43, p = 0.002 vs r = 0.32, p = 0.026). Cats with higher fructosamine had lower serum symmetric dimethylarginine concentrations.Conclusion: The present study does not suggest an effect of obesity on renal function in domestic cats.Clinical relevance: Fructosamine might be of value for the diagnosis of prediabetes mellitus in cats.

Influence of clinical setting and cat characteristics on indirectly measured blood pressure and pulse rate in healthy Birman, Norwegian Forest, and Domestic Shorthair cats

BACKGROUND

Measured indirect blood pressure (BP) results in cats in a clinical environment might be affected by stress and characteristics of the cats.

HYPOTHESIS

To investigate the influence of clinical setting, cat characteristics, and life situation on BP and pulse rate (PR) in healthy cats.

ANIMALS

Ninety-four healthy Domestic Shorthair, Birman and Norwegian Forest cats.

METHODS

Blood pressure measured by high-definition oscillometry in 3 settings: cat placed in its own carrier with veterinarian present; cat placed in carrier with owner alone present; and cat placed on table with veterinarian present. Statistical analyses were performed using mixed linear models.

RESULTS

Systolic BP (SBP) did not differ among settings. Higher mean arterial pressure (MAP), diastolic BP (DBP), and PR were found when measurements were performed with cat placed on table, rather than in carrier. Coefficients of variation (CVs) higher for SBP, MAP, DBP, and PR when measured with cat placed on table than in carrier. Birman cats had lower BP than other breeds. Systolic BP, MAP, DBP, and PR increased with age. Cats allowed outdoors had lower PR than cats living strictly indoors.

CONCLUSION AND CLINICAL IMPORTANCE

No difference in SBP was found among settings, but measuring BP with the cat placed on the examination table gave higher MAP, DBP, PR, and CV than measuring BP with the cat in its carrier. Breed affected BP, with lower BP in Birman cats than other breeds. Blood pressure increased with age. Pulse rate was lower in cats allowed outdoors than cats living strictly indoors.

Effects of Waiting Room and Feline Facial Pheromone Experience on Blood Pressure in Cats

Obtaining accurate blood pressure measurements in cats is challenging due to the stressful nature of clinic visits. The objective of this study was to evaluate the effects of veterinary clinic waiting experiences and a feline pheromone spray on blood pressure in the cat. We hypothesized that reduced stress associated with bypassing the waiting room and use of synthetic feline facial pheromone (FFP) spray would result in lower blood pressure. A 2 × 2 factorial design involved two rooms and two FFP treatments. Thirty-nine healthy adult cats were recruited and were systematically assigned to four treatment combinations administered over four visits in 2016 and 2017. Cats were kept in the hospital waiting room or were taken directly to the exam room, with or without FFP treatment. All cats were then acclimated to the exam room for an additional 10 min, where vocalizations were recorded manually, before blood pressure measurements were collected using Doppler ultrasonography. Data were analyzed using generalized linear mixed models, with room × FFP interaction, visit, sex, and trial year in the model. There was no significant effect of waiting room by FFP interaction on blood pressure (n = 0.95). Mean blood pressure was significantly higher at visit 1 than visits 2 and 4 (P < 0.01), but higher at visit 3 than visit 2 (n = 0.02). Mean blood pressure was higher in males (n = 0.01), and males were more likely to be categorized as borderline hypertensive/hypertensive or severely hypertensive (n = 0.01). Number of vocalizations was significantly associated with waiting room by FFP interactions (P < 0.01), with fewer vocalizations associated with bypassing the waiting room and when FFP was provided. In conclusion, although we found some behavioral evidence supporting stress reduction when feline patients bypass the waiting room and are provided with FFP, these interventions did not result in lower blood pressure in a clinical setting.

2021 AAHA/AAFP Feline Life Stage Guidelines

The guidelines, authored by a Task Force of experts in feline clinical medicine, are an update and extension of the AAFP-AAHA Feline Life Stage Guidelines published in 2010. The guidelines are published simultaneously in the Journal of Feline Medicine and Surgery (volume 23, issue 3, pages 211-233, DOI: 10.1177/1098612X21993657) and the Journal of the American Animal Hospital Association (volume 57, issue 2, pages 51-72, DOI: 10.5326/JAAHA-MS-7189). A noteworthy change from the earlier guidelines is the division of the cat's lifespan into a five-stage grouping with four distinct age-related stages (kitten, young adult, mature adult, and senior) as well as an end-of-life stage, instead of the previous six. This simplified grouping is consistent with how pet owners generally perceive their cat's maturation and aging process, and provides a readily understood basis for an evolving, individualized, lifelong feline healthcare strategy. The guidelines include a comprehensive table on the components of a feline wellness visit that provides a framework for systematically implementing an individualized life stage approach to feline healthcare. Included are recommendations for managing the most critical health-related factors in relation to a cat's life stage. These recommendations are further explained in the following categories: behavior and environmental needs; elimination; life stage nutrition and weight management; oral health; parasite control; vaccination; zoonoses and human safety; and recommended diagnostics based on life stage. A discussion on overcoming barriers to veterinary visits by cat owners offers practical advice on one of the most challenging aspects of delivering regular feline healthcare.

2021 AAHA/AAFP Feline Life Stage Guidelines

The guidelines, authored by a Task Force of experts in feline clinical medicine, are an update and extension of the AAFP-AAHA Feline Life Stage Guidelines published in 2010. The guidelines are published simultaneously in the Journal of Feline Medicine and Surgery (volume 23, issue 3, pages 211-233, DOI: 10.1177/1098612X21993657) and the Journal of the American Animal Hospital Association (volume 57, issue 2, pages 51-72, DOI: 10.5326/JAAHA-MS-7189). A noteworthy change from the earlier guidelines is the division of the cat's lifespan into a five-stage grouping with four distinct age-related stages (kitten, young adult, mature adult, and senior) as well as an end-of-life stage, instead of the previous six. This simplified grouping is consistent with how pet owners generally perceive their cat's maturation and aging process, and provides a readily understood basis for an evolving, individualized, lifelong feline healthcare strategy. The guidelines include a comprehensive table on the components of a feline wellness visit that provides a framework for systematically implementing an individualized life stage approach to feline healthcare. Included are recommendations for managing the most critical health-related factors in relation to a cat's life stage. These recommendations are further explained in the following categories: behavior and environmental needs; elimination; life stage nutrition and weight management; oral health; parasite control; vaccination; zoonoses and human safety; and recommended diagnostics based on life stage. A discussion on overcoming barriers to veterinary visits by cat owners offers practical advice on one of the most challenging aspects of delivering regular feline healthcare.

Comparison of Doppler ultrasonic and oscillometric devices (with or without proprietary optimisations) for non-invasive blood pressure measurement in conscious cats

Objectives

This study compared Doppler and oscillometric (PetMAP+) devices (with or without proprietary optimisations) for the non-invasive measurement of blood pressure in conscious cats.

Methods

Twenty-three cats were enrolled; however, five were excluded as fewer than five measurements were obtained for each assessment. All measurements were obtained according to American College of Veterinary Internal Medicine consensus guidelines. Oscillometric device modes A and B were operated according to the manufacturer’s guidelines. Doppler and oscillometric devices were used alternately as the first device.

Results

Systolic arterial blood pressure (SAP) measurements were obtained by Doppler (SAPd) and oscillometry; the mean of each set of five values was used for statistical analysis. There was a significant difference between SAPd and SAP measurements in oscillometric modes A (P <0.001) and B (P <0.001). While both modes measured SAP higher than SAPd, B had a smaller bias (+15.72 mmHg) and narrower limits of agreement (LOA). There was also a significant difference between SAPd and mean arterial pressure (MAP) on oscillometric modes A (P = 0.002) and B (P <0.001). Both modes’ MAP readings were lower than SAPd and oscillometric A MAP was closer to SAPd (–14.94 mmHg), with a smaller bias and narrower LOA.

Conclusions and relevance

The findings support that Doppler and oscillometric devices cannot be used interchangeably, with or without proprietary optimisations. Methodology should always be taken into account and reference intervals (RIs) need to be defined for the different methodologies. Until methodology-specific RIs are published, definitive diagnosis of hypertension and sub-staging of patients with kidney disease according to the International Renal Interest Society guidelines remains challenging.

Hypertension: Why Is It Critical?

Hypertension is a common problem, particularly in older cats. Hypertension secondary to a concurrent disease is the most common form of hypertension in cats, particularly in association with chronic kidney disease or hyperthyroidism. However, idiopathic hypertension may account for up to 24% of cases. Any form of persistent hypertension risks target organ damage (TOD), therefore measurement of blood pressure is vital in at-risk cats to identify occult hypertension before TOD occurs. This article addresses when and how to perform blood pressure measurement in cats, TOD that has been documented in this species, and our evidence basis for treating hypertension.

Assessment of serum symmetric dimethylarginine and creatinine concentrations in hyperthyroid cats before and after a fixed dose of orally administered radioiodine

Background

Serum symmetric dimethylarginine (SDMA) is a sensitive renal biomarker for detecting early chronic kidney disease (CKD) in nonhyperthyroid cats, but knowledge regarding its performance in hyperthyroid cats remains limited.

Objectives

To determine the relationship between serum SDMA, creatinine and total thyroxine (TT4) concentrations in hyperthyroid cats before (T0) and 3 months after (T1) receiving a PO fixed dose of radioiodine.

Animals

Eighty client‐owned hyperthyroid cats.

Methods

Prospective cohort study. Serum TT4, and SDMA, creatinine concentrations, and urine specific gravity were measured at T0 and T1. Nonparametric tests were used to determine the relationship among SDMA, and creatinine and TT4 concentrations. Agreement between SDMA and creatinine regarding CKD staging at both time points was assessed using Goodman and Kruskal's gamma statistic.

Results

Mean serum SDMA concentration increased after treatment of hyperthyroidism. However, 21 of 75 cats experienced a decrease in SDMA between T0 and T1, whereas creatinine decreased in only 2 cats. A moderate correlation between SDMA and creatinine was seen at T1 (r = 0.53; P < .001) but not at T0 (r = 0.13; P = .25). Where assessable at T1, poor agreement was observed between SDMA and creatinine and CKD stage (Goodman and Kruskal's gamma 0.20; P = .29).

Conclusions and clinical importance

Discordant outcomes between SDMA and creatinine after radioiodine treatment in cats with hyperthyroidism suggest extrarenal factors may interfere with the reliability of SDMA to adequately reflect renal function. As a result, SDMA should not be interpreted in isolation in hyperthyroid cats treated with radioiodine.

Early Renal Involvement in Cats with Natural Feline Morbillivirus Infection

Simple Summary

Feline morbillivirus is a newly discovered paramyxovirus infecting domestic cats. Its pathogenetic role in domestic cats is still debated, however some evidences suggest a potential involvement of this novel feline virus in the pathogenesis of feline chronic kidney disease. In this study, clinical data of cats infected by morbillivirus were retrospectively reviewed and compared with data obtained from healthy cats and cats affected by chronic kidney disease. The results of the present study suggest that this infection can be associated with the presence of a sub-clinical kidney damage and with different grades of renal dysfunction in cats younger than those typically affected by chronic kidney disease.

Abstract

Feline morbillivirus (FeMV) is a newly discovered paramyxovirus infecting domestic cats and its role in the pathogenesis of feline chronic kidney disease (CKD) has been suggested, however not confirmed. The primary aim of the study was to evaluate the renal damage associated with FeMV infection in cats. In this retrospective study, clinical and clinicopathological data were compared among 14 FeMV naturally infected, 21 CKD and 22 healthy cats. FeMV positive cats had serum chemistry analytes and main urine chemistry results similar to the healthy subjects. FeMV positive cats had significantly decreased urine specific gravity (median 1054, range 1022–1065) and urine creatinine (median 227.23 mg/dL, range 83.02–489.75) when compared with healthy cats (median 1067, range 1040–1080, p < 0.001; median 406.50 mg/dL, range 195.32–575.58; p < 0.001, respectively). Urine protein:creatinine ratio (UPC) results of FeMV and CKD were not different (median 0.20, range 0.08–1.03; median 0.23, range 0.10–0.80, respectively), however UPC results were significantly increased in both groups, if compared with healthy cats (median 0.1, range 0.04–0.250, p < 0.01). Based on clinical data, serum creatinine concentration, urine specific gravity and UPC results, CKD was suspected by clinicians in 3/14 FeMV cats. Urine protein sodium-dodecyl-sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in 10/13 (77%) FeMV cats indicated a tubular pattern, with a decrease of uromodulin and an increase in the number and intensity of low molecular weight proteins. FeMV infection can be associated with different grades of renal dysfunction ranging from mild tubular proteinuria with less concentrated urine to azotemia in cats younger than those typically affected by CKD.

Complex Disease Management: Managing a Cat with Comorbidities

Many older cats often suffer concurrently from multiple conditions. By focusing on the common concerns, rather than conflicting requirements, a management program can be devised. Optimize hydration, nutrition, and ensure comfort though providing analgesia and a low-stress environment in which the patient's feline-specific nature is respected both in the clinic and at home. Additional requirements, such as hyperphosphatemia or hypokalemia, can be met using treatments outside of diet, if necessary.

The Multicomponent, Multitarget Therapy SUC in Cats with Chronic Kidney Disease: A Multicenter, Prospective, Observational, Nonrandomized Cohort Study

BACKGROUND

We compared the natural multicomponent, multitarget therapy SUC (Solidago compositum ad us. vet., Ubichinon compositum and Coenzyme compositum, Heel GmbH, Baden-Baden, Germany) to the well-known angiotensin-converting enzyme inhibitor benazepril in a prospective, observational, nonrandomized, two-arm cohort study of cats with chronic kidney disease (CKD). The objective was to assess the tolerability and the effectiveness of SUC in cats with CKD.

MATERIAL AND METHODS

One hundred thirty-six cats were screened for CKD, and 70 cats were eligible for the study. Thirty-three cats were assigned to the SUC treatment, and 35 cats received benazepril. All cats were diagnosed with CKD. The follow-up period was 168 days. Response was assessed as an improved or stable serum creatinine from baseline to the end of the study. Additionally, a clinical summary score, as measure of quality of life, was evaluated.

RESULTS

Serum creatinine remained close to baseline in both study groups with slightly improved values in the SUC group. The clinical summary score improved significantly in the SUC group on days 3, 7, 28, 56 and 112, but not on day 168.

CONCLUSIONS

Within the limitations of the study, the results carry implications for the usefulness of SUC as an interesting new treatment option for feline CKD. The results indicate that SUC might be more effective if given at least twice weekly.

Antioxidant defence and oxidative stress markers in cats with asymptomatic and symptomatic hypertrophic cardiomyopathy: a pilot study

Background

Hypertrophic cardiomyopathy is the most common cardiovascular cause of death in cats. Although the majority of cats remain asymptomatic, some may develop signs of chronic heart failure due to diastolic failure, arterial thromboembolism (ATE) or sudden cardiac death. Therefore, it is crucial to identify individuals that are in high risk of developing cardiac complications before the onset of life-threatening signs. Oxidative stress is the imbalance between the production and neutralisation of reactive oxygen species. Uncontrolled reactive oxygen species overproduction leads to protein and lipid peroxidation and damages the DNA strands, injuring the cells and leading to their death. The aim of the study was to evaluate the oxidative state in cats with hypertrophic cardiomyopathy and healthy controls.

Results

In total, 30 cats divided into three groups were assessed: animals with clinically evident hypertrophic cardiomyopathy (HCM; n = 8), subclinical hypertrophic cardiomyopathy (SUB-HCM; n = 11) and healthy controls (n = 11). The activity of superoxide dismutase was statistically significantly lower in animals with symptomatic and asymptomatic hypertrophic cardiomyopathy (HCM 0.99 ± 0.35 U/mL; SUB-HCM 1.39 ± 0.4 U/mL) compared to healthy cats (2.07 ± 0.76 U/mL, p < 0.01). The activity of catalase was significantly lower in the SUB-HCM group (19.4 ± 4.2 nmol/min/mL) compared to the HCM (23.6 ± 5.9 nmol/min/mL) and the control (30 ± 7.5 nmol/min/mL, p < 0.01) group. The activity of glutathione peroxidase was 4196 ± 353 nmol/min/mL in the HCM group, 4331 ± 451 nmol/min/mL in the SUB-HCM group and 4037 ± 341 nmol/min/mL in the control group and did not differ significantly between groups. The total antioxidant capacity of plasma was 602 ± 65.5 copper reducing equivalents (CRE) in the HCM group, 605.9 ± 39.9 CRE in the SUB-HCM group and 629 ± 77.5 CRE in the healthy cats and did not differ significantly between the groups.

Conclusions

Activities of superoxide dismutase and catalase differed in cats with hypertrophic cardiomyopathy, however the activity of the latter was only significantly lower in asymptomatic stage of the disease. The potentially beneficial effect of antioxidative substances on the disease progression in the asymptomatic and symptomatic stage of this disease should also be examined.

Effects of oral trazodone on echocardiographic and hemodynamic variables in healthy cats

OBJECTIVES

The purpose of this study was to evaluate the effects of oral trazodone on echocardiographic variables, heart rate (HR) and blood pressure (BP) in healthy cats.

METHODS

Client-owned domestic cats between 2 and 8 years of age were recruited. Cats were considered healthy based on physical examination, complete blood count, blood chemistry profile, urinalysis, total thyroxine concentration, non-invasive BP measurement by Doppler method and a screening transthoracic echocardiogram with simultaneous electrocardiogram. Echocardiographic variables assessed pre-trazodone and 90-120 mins post-trazodone (50 mg PO) included left ventricular internal diameter in systole and diastole, interventricular septal and left ventricular free-wall thickness in systole and diastole, left atrial size, left auricular function and left ventricular diastolic function assessed by spectral Doppler transmitral and pulmonary venous flow velocities, and tissue Doppler profiles. Mean echocardiographic and hemodynamic variables were calculated for pre- and post-trazodone examinations for each cat. Pre- and post-trazodone variables were analyzed with a paired t-test with significance set at P <0.05.

RESULTS

Twelve healthy cats were evaluated. Trazodone was administered to all cats and a sedative effect was observed. There were no clinically significant differences in any echocardiographic variables post-trazodone administration. Systolic BP was significantly decreased after trazodone (P = 0.001) with no significant change in HR.

CONCLUSIONS AND RELEVANCE

Trazodone did not alter echocardiographic variables, in a clinically relevant manner, in this group of healthy cats. Trazodone may aid in obtaining transthoracic echocardiograms without affecting HR or echocardiographic variables but may significantly lower BP in healthy cats.

Serum concentration of homocysteine in spontaneous feline chronic kidney disease

Serum homocysteine (Hcy) increases in people and dogs with chronic kidney disease (CKD). Hyperhomocysteinemia (HHcy) has also been associated with CKD-related hypertension and proteinuria. The aims of this study were to: (1) validate an enzymatic method for quantification of Hcy in feline serum; (2) evaluate whether HHcy was associated with the presence and severity of CKD, proteinuria or hypertension; and (3) determine whether HHcy could predict disease progression. The intra- and inter-assay coefficients of variation (CVs) and the recovery rates of linearity under dilution and spiking recovery tests of the enzymatic method were 3.1-6.7%, 11.6-12.5%, 96.9±5.4% and 96.9±5.4%, respectively. Healthy cats at risk of CKD (n=17) and cats with CKD (n=19) were sampled over a 6-month period (63 samples in total). Cats with CKD had significantly higher Hcy concentrations (P=0.005) than cats at risk. The concentration of Hcy was higher (P=0.002) in moderate-severe CKD than in mild CKD and correlated moderately with serum creatinine (P<0.0001; r=0.51). The concentration of Hcy increased with the magnitude of proteinuria and correlated weakly with urinary protein to creatinine ratio (P=0.045; r=0.26). HHcy was not associated with hypertension. At the time of enrollment, Hcy concentration was significantly higher (P=0.046) in cats that developed CKD compared to cats that remained stable. The enzymatic method for Hcy measurement in feline serum was precise and accurate. HHcy was relatively common in cats with advanced CKD and seemed to predict disease progression, but further studies are warranted.

Hypertensive ocular disease in cats: A guide to fundic lesions to facilitate early diagnosis

PRACTICAL RELEVANCE

Systemic hypertension is common in older cats and can result in damage to organs with a rich arteriolar supply such as the eyes, kidneys, myocardium and brain. Hypertensive disease in these organs is known as target organ damage (TOD). Disease in the eye resulting from hypertension is the most easily identifiable form of TOD and can often be the reason the cat is presented to the veterinarian. Routine blood pressure measurement and fundic examination allows cats with hypertensive ocular lesions to be detected early in the course of the disease, when the lesions have the best chance of responding to treatment.

CLINICAL CHALLENGES

Detecting early evidence of TOD in the fundus requires a veterinarian to be competent in recognising lesions associated with mild hypertensive disease, as well as the more easily recognised advanced lesions that frequently result in impaired vision and blindness.

AUDIENCE

This review is written for all veterinarians who treat cats. It provides information and images to facilitate and guide veterinarians performing fundoscopy in cats, in particular in those over 7 years of age, with the aim of diagnosing hypertensive ocular lesions when they are present.

EQUIPMENT

The clinical manifestations of hypertensive ocular disease can be detected non-invasively with inexpensive equipment. A summary of the equipment available for general practitioners to perform fundoscopy is provided.

EVIDENCE BASE

This is a comprehensive review of the literature on hypertensive ocular disease in cats. The author has also included images of hypertensive ocular lesions taken in general practice to highlight the variety of lesions that can be detected.