Longitudinal prevalence of hypertension, proteinuria, and retinopathy in dogs with spontaneous diabetes mellitus

Effect of sodium-glucose cotransporter 2 inhibitor canagliflozin on interstitial glucose concentration in insulin-treated diabetic dogs

BACKGROUND

The utility of sodium-glucose cotransporter 2 inhibitors (SGLT2i) has not been reported in insulin-treated diabetic dogs.

HYPOTHESIS

Canagliflozin, a PO-administered SGLT2i, decreases interstitial glucose concentration (IG) in insulin-treated diabetic dogs.

ANIMALS

Five insulin-treated diabetic dogs.

METHODS

Uncontrolled open label longitudinal study. Canagliflozin (2-4 mg/kg/day PO) was added to an unchanged insulin dose for 7 days. Fractional excretion of glucose was calculated by dividing the product of urine glucose and serum creatinine concentrations by the product of serum glucose and urine creatinine concentrations. Hypoglycemia was defined as IG <60 mg/dL.

RESULTS

Median IG in 2869 measurements obtained while dogs were treated with insulin and canagliflozin was 87 mg/dL (range, 40-500 mg/dL) and was significantly lower than median IG in 1426 measurements obtained while dogs were treated with insulin alone (212 mg/dL; range, 41-500 mg/dL; P < .001). Median fractional excretion of glucose when dogs were treated with insulin and canagliflozin was 1.1% (range, 0.9%-2.0%), significantly higher than when dogs were treated with insulin alone (0.3%; range, 0.01%-1.0%; P = .04). The frequency of hypoglycemia was higher in dogs treated with insulin and canagliflozin (544 of 2869 IG measurements, 19%) compared with the frequency of hypoglycemia in dogs treated with insulin alone (52 of 1426 IG measurements, 4%; P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

Canagliflozin may have a role in improving glycemic control in insulin-treated diabetic dogs, but the dose of insulin should be decreased when adding canagliflozin to insulin treatment.

A comprehensive analysis of albuminuria in canine chronic kidney disease

BACKGROUND

Albuminuria, an important marker of decreased kidney function in chronic kidney disease (CKD), is not routinely used for CKD detection or proteinuria appearance. Its relationships with biochemical parameters and blood pressure in dogs are poorly understood.

OBJECTIVES

This study aimed to evaluate the relationship of albuminuria with various CKD markers, its correlation with the urinary protein to creatinine ratio (UPC), and hypertension in dogs with early stages of CKD. It also sought to determine the usability of the urinary albumin to creatinine ratio (UAC) for CKD screening.

METHODS

The study reviewed records of 102 dogs, categorising them into four groups based on disease status. UAC and UPC ratio, biochemistry and haematology variables, age, and systolic blood pressure were determined.

RESULTS

The Pearson's correlation coefficient between log-transformed values of UPC and UAC was r = 0.902 (95% CI: 0.87 to 0.93). Median UAC ratio values were 2.1 mg/g for the Healthy control group (n = 17), 54.2 mg/g for early stages CKD (n = 42), 5.8 mg/g for Acute sick control (n = 30), and 104 mg/g for Chronic sick control (n = 13). Thresholding UAC ratio as an indicator for impaired kidney function with the threshold of 10 mg/g (established based on the receiver operating characteristic curve) had a sensitivity 81.8%, specificity of 89.4%, positive predictive value (PPV) 90%, and negative predictive value (NPV) 80.1%. The correlation of UAC with biochemistry and haematology variables was statistically significant; for SDMA (μg/L), it was r = 0.566 and for other variables, it was weak to moderate. UAC was markedly elevated in cases of severe hypertension.

CONCLUSIONS

UAC ratio was significantly different among dogs with impaired and not impaired kidney function. The correlation strength for the UAC and UPC ratios was high. UAC ratio may be a promising marker for proteinuria analysis in dogs with CKD or other kidney function alterations.

Short-term glycemic variability in non-diabetic, non-obese dogs assessed by common glycemic variability indices

Glycemic variability (GV) refers to swings in blood glucose levels and is an emerging measure of glycemic control in clinical practice. It is associated with micro- and macrovascular complications and poor clinical outcomes in diabetic humans. Although an integral part of patient assessment in human patients, it is to a large extent neglected in insulin-treated diabetic dogs. This prospective pilot study was performed to describe canine within-day GV in non-diabetic dogs with the aim to provide a basis for the interpretation of daily glucose profiles, and to promote GV as an accessible tool for future studies in veterinary medicine. Interstitial glucose concentrations of ten non-diabetic, non-obese beagles were continuously measured over a 48-h period using a flash glucose monitoring system. GV was assessed using the common indices MAGE (mean amplitude of glycemic excursion), GVP (Glycemic variability percentage) and CV (coefficient of variation). A total of 2260 sensor measurements were obtained, ranging from 3.7 mmol/L (67 mg/dL) to 8.5 mmol/L (153 mg/dL). Glucose profiles suggested a meal-dependent circadian rhythmicity with small but significant surges during the feeding periods. No differences in GV indices were observed between day and night periods (p > 0.05). The MAGE (mmol/L), GVP (%) and CV (%) were 0.86 (± 0.19), 7.37 (± 1.65), 6.72 (± 0.89) on day one, and 0.83 (± 0.18), 6.95 (± 1.52), 6.72 (± 1.53) on day two, respectively. The results of this study suggest that GV is low in non-diabetic dogs and that glucose concentrations are kept within narrow ranges.

Manifestations of systemic disease in the retina and fundus of cats and dogs

The fundus is unique in that it is the only part of the body that allows for a noninvasive and uninterrupted view of vasculature and nervous tissue. Utilization of this can be a powerful tool in uncovering salient incidental findings which point to underlying systemic diseases, and for monitoring response to therapy. Retinal venules and arterioles allow the clinician to assess changes in vascular color, diameter, outline, and tortuosity. The retina and optic nerve may exhibit changes associated with increased or decreased thickness, inflammatory infiltrates, hemorrhages, and detachments. While some retinal manifestations of systemic disease may be nonspecific, others are pathognomonic, and may be the presenting sign for a systemic illness. The examination of the fundus is an essential part of the comprehensive physical examination. Systemic diseases which may present with retinal abnormalities include a variety of disease classifications, as represented by the DAMNIT-V acronym, for Degenerative/Developmental, Anomalous, Metabolic, Neoplastic, Nutritional, Inflammatory (Infectious/Immune-mediated/ischemic), Toxic, Traumatic and Vascular. This review details systemic illnesses or syndromes that have been reported to manifest in the fundus of companion animals and discusses key aspects in differentiating their underlying cause. Normal variations in retinal anatomy and morphology are also considered.

Factors associated with thrombotic disease in dogs with renal proteinuria: A retrospective of 150 cases

BACKGROUND

Knowledge of additional risk factors for thrombotic disease (TD) among dogs with renal proteinuria is limited; these might differ for TD affecting the systemic arterial (AT), systemic venous (VT), and pulmonary circulation (PT).

HYPOTHESIS/OBJECTIVES

To compare signalment and clinicopathological data between dogs with renal proteinuria with or without TD, and between dogs with AT, VT, and PT.

ANIMALS

One hundred fifty client-owned dogs with renal proteinuria, 50 of which had TD.

METHODS

Retrospective case-controlled study. A database search (2004-2021) identified proteinuric dogs (UPC > 2) with and without TD. Clinicopathological data were obtained from the records. TD and non-TD (NTD) groups were compared by binary logistic regression, and AT, VT, and PT groups by multinomial regression. Normal data presented as mean ± SD, non-normal data presented as median [25th, 75th percentiles].

RESULTS

Cavalier King Charles Spaniels were overrepresented in the TD group (OR = 98.8, 95% CI 2.09-4671, P = .02). Compared to NTD cases, TD cases had higher concentration of neutrophils (11.06 [8.92, 16.58] × 109 /L vs 7.31 [5.63, 11.06] × 109 /L, P = .02), and lower concentration of eosinophils (0 [0, 0.21] × 109 /L vs 0.17 [0.04, 0.41] × 109 /L, P = .002) in blood, and lower serum albumin (2.45 ± 0.73 g/dL vs 2.83 ± 0.73 g/dL, P = .04). AT cases had higher serum albumin concentrations than VT cases (2.73 ± 0.48 g/dL vs 2.17 ± 0.49 g/dL, P = .03) and were older than PT cases (10.6 ± 2.6 years vs 7.0 ± 4.3 years, P = .008). VT cases were older (9.1 ± 4.2 years vs 7.0 ± 4.3 years, P = .008) and had higher serum cholesterol concentration (398 [309-692 mg/dL] vs 255 [155-402 mg/dL], P = .03) than PT cases.

CONCLUSIONS AND CLINICAL IMPORTANCE

Differences between thrombus locations could reflect differences in pathogenesis.

The relationships between sediment findings and culture results and the presence of proteinuria in canine urine samples

OBJECTIVES

To assess relationships between urine sediment and microbial culture findings and the presence of proteinuria in canine urine samples, and to assess the change in the percentage of proteinuric samples and urine protein-to-creatinine ratio when urine abnormalities resolve.

MATERIALS AND METHODS

Canine urine samples collected via cystocentesis and submitted for culture and contemporaneous urinalysis (including urine protein-to-creatinine ratio) were retrospectively identified. Dogs receiving corticosteroids were excluded. Associations between haematuria (red blood cells>5/high-power field), pyuria (white blood cells>5/high-power field), presence of microorganisms on microscopy, active sediment, and positive culture and proteinuria (urine protein-to-creatinine ratio>0.5) were investigated. Patient characteristics were considered possible confounders. In dogs with repeat urinalysis, the associations between active sediment and positive culture resolution on proteinuria and urine protein-to-creatinine ratio were assessed.

RESULTS

One hundred and ninety-two of 491 samples were proteinuric (39.1%). Age was positively associated with proteinuria. In the multivariable analysis corrected for age, active sediment was the only variable significantly associated with proteinuria (adjusted odds ratio: 2.12; 95% confidence interval: 1.44 to 3.11); however, only 49.8% of samples with active sediment were proteinuric. Neither resolution of active sediment nor positive culture were associated with reduced proportions of proteinuric samples (from 57.9% to 42.1% and from 40.0% to 25.0%, respectively) or significant reductions in urine protein-to-creatinine ratio (median change: -0.16 and -0.14, respectively).

CLINICAL SIGNIFICANCE

Attributing proteinuria to urinalysis abnormalities or a positive urine culture in canine cystocentesis samples is not supported by our findings, and could result in alternative causes of proteinuria (e.g. renal proteinuria) being overlooked.

Concurrent disorders of cats with diabetes mellitus and arterial systolic hypertension

OBJECTIVES

The aim of the present study was to report the concurrent disorders and treatment success of cats with diabetes mellitus (DM) and arterial systolic hypertension (SH).

METHODS

A retrospective longitudinal study was conducted of 17 cats with DM and SH that were examined at a university teaching hospital between 1 January 2011 and 31 December 2021. The medical records of diabetic cats were searched for the keywords 'hypertension', 'blood pressure', 'amlodipine', 'benazepril' and 'telmisartan' to identify cats with SH, which was defined as systemic arterial blood pressure (SABP) ⩾160 mmHg, documented at least twice, over several days. Comorbidities, including chronic kidney disease and hyperthyroidism, were recorded. Medications used for the treatment of SH and the SABP response to treatment were also noted.

RESULTS

Most cats (13/17, 76%) with DM and SH had at least one other documented concurrent illness that could contribute to SH, including chronic kidney disease (12/17 cats, 71%), hyperthyroidism (4/17, 23%) and functional adrenocortical mass secreting either aldosterone alone (1/17, 6%) or glucocorticoids, and possibly also aldosterone (1/17, 6%). Out of 17 cats, 15 (88%) were treated with amlodipine, and none were treated with an angiotensin converting enzyme inhibitor or an angiotensin II receptor blocker. Mean SABP at the time of diagnosis of SH was 210 ± 23 mmHg and was significantly higher than the mean SABP at the first and second follow-up examinations after the introduction of amlodipine treatment (175 ± 33 mmHg, P = 0.008 and 172 ± 26 mmHg, P = 0.01, respectively).

CONCLUSIONS AND RELEVANCE

Cats with DM and SH should be evaluated for the presence of chronic kidney disease, hyperthyroidism and functional adrenal masses. Treatment with amlodipine appears to be effective in lowering SABP in cats with DM and SH.

Prevalence of ocular findings and their association with glycemia in dogs with diabetes mellitus: A 10-year clinical study (2009-2019)

Background

Although ocular findings in diabetic patients are well described, prevalence data for those is unknown.

Aim

To describe the prevalence of ocular findings and their association with glycemia in dogs with diabetes mellitus.

Methods

Medical records from diabetic dogs assessed by the ophthalmology and the internal medicine services at the Veterinary Teaching Hospital of the Autonomous University of Barcelona were reviewed (2009-2019).

Results

Seventy-five dogs (150 eyes) of both genders (51/75 females; 68% and 24/75 males; 32%) and a mean age of 9.37 ± 2.43 years, were included. The most common ocular findings were cataracts (146/150; 97.3%), vitreous degeneration (45/98; 45.9%), anterior uveitis (47/150; 31.3%), aqueous deficiency dry eye (ADDE) (33/150; 22%), diffuse corneal edema (31/150; 20.7%), non-proliferative retinopathy (13/98; 13.3%), and lipid keratopathy (9/150; 6%). The most prevalent type of cataracts observed (78/146; 53.4%) was intumescent, which was commonly accompanied by non-proliferative retinopathy (p = 0.003). Among the diabetic dogs, blood glucose levels were statistically higher in dogs with non-proliferative retinopathy or anterior uveitis (p < 0.005).

Conclusions

Ocular complications of diabetes mellitus in dogs are numerous, being the most frequent intumescent cataracts, vitreous degeneration, anterior uveitis, ADDE, diffuse corneal edema, and non-proliferative retinopathy. This high prevalence warrants a more detailed ophthalmic evaluation in diabetic dogs especially for those undergoing cataract surgery. Furthermore, a predisposition for anterior segment inflammation and non-proliferative retinopathy is suggested when fasting plasma glucose is higher than 600 mg/dl..

Nutritional Management of Cats and Dogs with Diabetes Mellitus

This article reviews the nutritional assessment and management of diabetic dogs and cats. It discusses how to determine appropriate nutritional goals for individual patients, including comorbid patients with diabetes. Considerations for macronutrient and micronutrient modifications will be reviewed.

Anesthetic Considerations in Dogs and Cats with Diabetes Mellitus

Understanding the effects of diabetes and hyperglycemia on hydration, acid-base status, and immune function is paramount to safely anesthetizing diabetic cats and dogs. Preoperative stabilization of glucose concentrations, hydration, and electrolyte imbalances is key to minimizing morbidity and mortality. Blood glucose monitoring perioperatively will help guide insulin and dextrose administration. Specific anesthetic considerations, and peri-anesthetic management of animals with diabetes mellitus, including anesthetic drugs and recommended insulin protocols are discussed.

Diabetes Mellitus and the Kidneys

The pathomechanisms implicated in diabetic kidney disease in people are present in dogs and cats and, in theory, could lead to renal complications in companion animals with long-standing diabetes mellitus. However, these renal complications develop during a long period, and there is little to no clinical evidence that they could lead to chronic kidney disease in companion animals.

Weight loss modifies lipid peroxidation and symmetric dimethylarginine levels in obese dogs

In obese dogs, oxidative stress is associated with inflammatory processes and systemic endocrine imbalances. Monitoring oxidative status is an early and valuable means of obesity control as it is a marker of weight loss, which leads to a reduction in oxidative status or injury potential. The objective of this study was to investgate the changes in the concentrations of thiobarbituric acid reactive substances (TBARS) and symmetric dimethylarginine (SDMA) in obese female dogs subjected to an 8-week weight-loss program. We included obese female dogs without comorbidities and with body condition scores (BCS) of 8 and 9 out of 9. In addition to TBARS and SDMA assessments, laboratory tests of blood and urine (blood count; levels of serum biochemistry; albumin, alanine aminotransferase, alkaline phosphatase, creatinine, urea, triglycerides, cholesterol, and glucose; urinalysis; and albuminuria), systolic blood pressure, and hormone concentrations (insulin, cortisol, and free thyroxine) were carried out before and after the weight-loss program. All the obese dogs presented high TBARS levels. After the program, the dogs showed significant reductions in TBARS (P = 0.005) and SDMA (P = 0.0013). In conclusion, obese female dogs were prone to lipid peroxidation and the TBARS and SDMA levels decreased after the 8-week weight-loss program.

Evaluation of presentation, treatment and outcome in hypertensive emergency in dogs and cats: 15 cases (2003-2019)

OBJECTIVES

Hypertensive emergency is well recognised in human medicine, yet there is limited veterinary evidence. This study aimed to determine the presentation, treatment and outcome in dogs and cats with hypertensive emergency.

MATERIALS AND METHODS

A retrospective case series of dogs and cats with hypertensive emergency identified as follows: acute history with non-invasive Doppler systolic blood pressure greater than 180 mmHg and target organ damage including acute onset seizures, altered mentation with or without lateral recumbency or blindness. Data collected included signalment, history, physical examination and clinicopathological findings, systolic blood pressure, antihypertensive treatment and outcome.

RESULTS

Seven dogs and eight cats were included presenting with seizures (n=9), blindness (n=4), altered mentation with (n=2) or without (n=2) lateral recumbency. Median age was 9 years (range 1 to 15) and duration of clinical signs before presentation was 1.5 days (range 1 to 15). Median systolic blood pressure on presentation was 230 mmHg (range 190 to 300). Amlodipine was the most common first-line agent (n=10), followed by hydralazine (n=4) and hypertonic saline (n=1). Aetiology of hypertensive emergency was acute kidney injury (n=9), idiopathic hypertension (n=3), hyperthyroidism (n=1), lymphoma (n=1) and suspected cutaneous and renal glomerular vasculopathy (n=1). Five cats and three dogs survived to discharge with an overall survival of 53.3%.

CLINICAL SIGNIFICANCE

Hypertensive emergencies had various presenting signs in this series. AKI was considered to be the cause of hypertension in the majority of patients. Further evaluation of treatment for hypertensive emergencies is warranted, considering almost half of the cases did not survive to discharge.

Establishment of a reference interval for urinary albumin-to-creatinine ratio in dogs

BACKGROUND

Albuminuria is an important marker of renal damage and can precede proteinuria; thus, it can be a useful analyte in the early diagnosis of kidney diseases. Albuminuria has also been found in dogs with hypertension, inflammatory, infectious, and neoplastic diseases.

OBJECTIVES

The aim of this study was to establish a reference interval (RI) for albuminuria in dogs.

METHODS

One hundred sixty-four clinically healthy dogs were enrolled in the study. Urinary albumin was determined by the immunoturbidimetric method, and albumin excretion was expressed as the urinary albumin-to-creatinine (UAC) ratio. The RI for UAC was established.

RESULTS

After exclusions, 124 dogs from 32 breeds remained. The median UAC of the study population was 3.0 mg/g (range: 0-48). The RI was defined as 0-19 mg/g (with a 90% CI for the upper limit of 13-28 mg/g). No significant difference was found between male and female dogs or between different age and body weight groups. The results of Sighthounds (n = 30) and Beagle dogs (n = 23) did not differ from the other breeds.

CONCLUSION

The canine RI of UAC is similar but somewhat narrower than the human RI.

Urinary Proteome Differences in Canine Diabetes with and without the Presence of Microalbuminuria

Simple Summary

Canine diabetes is a serious disease, which can lead to numerous complications. There are limited data on urine proteomics in dogs, and none of the effect of diabetes mellitus on the urine proteome. In this study we aimed to analyze the protein composition of the urine collected from the healthy animals and compare it with two diabetic groups (normoalbuminuric and microalbuminuric). There are significant differences between these three groups, and we believe that the identified proteins hold promise as a potential diagnostic tool, which can be later on used in clinical practice, and for better understanding of the disease.

Abstract

In this study we aimed to analyze the protein composition of the urine collected from the healthy animals and compare it to the two diabetic groups (DM I normoalbuminuric diabetic dogs; DM II diabetic dogs with microalbuminuria). We tried to identify potential urinary proteins which could be up- or downregulated in diabetic patients even before the appearance of microalbuminuria. Methods: After obtaining urine, we performed two-dimensional electrophoresis, followed by Delta2D software analysis, which allowed for selection and identification with MALDI-TOF spectrometry, statistically significant differentially expressed proteins. Our study revealed 286 common protein spots on 2D gels from the diabetic and control group. From these proteins five were positively identified by MALDI-TOF MS. To further evaluate the five differentiating proteins, the Panther program was used to assign them to appropriate biological process. Conclusion: Significant number of identified proteins play a role in intracellular signaling—vesicle formation, bonding, transport through membranes. This may suggest that first signs of kidney diabetic cellular impairment may be seen in the urine composition before any clinical signs occur.

Animal models of diabetic microvascular complications: Relevance to clinical features

Diabetes has become more common in recent years worldwide, and this growth is projected to continue in the future. The primary concern with diabetes is developing various complications, which significantly contribute to the disease's mortality and morbidity. Over time, the condition progresses from the pre-diabetic to the diabetic stage and then to the development of complications. Years and enormous resources are required to evaluate pharmacological interventions to prevent or delay the progression of disease or complications in humans. Appropriate screening models are required to gain a better understanding of both pathogenesis and potential therapeutic agents. Different species of animals are used to evaluate the pharmacological potentials and study the pathogenesis of the disease. Animal models are essential for research because they represent most of the structural, functional, and biochemical characteristics of human diseases. An ideal screening model should mimic the pathogenesis of the disease with identifiable characteristics. A thorough understanding of animal models is required for the experimental design to select an appropriate model. Each animal model has certain advantages and limitations. The present manuscript describes the animal models and their diagnostic characteristics to evaluate microvascular diabetic complications.

Is proteinuria a rare condition in apparently healthy and sick cats? A feline practice experience (2007-2018)

Background:

Proteinuria is assumed to be less frequent in cats than in dogs and is mainly associated with chronic kidney disease (CKD).

Aim:

The current study aimed to evaluate and compare urine protein-to-creatinine (UPC) values retrospectively in cats visited for comprehensive annual health check or for presenting systemic clinical signs related to CKD.

Methods:

UPC ratio was retrospectively evaluated in 112 owned cats, out of which 51 (45.5%) were apparently healthy cats according to their owners who visited for comprehensive annual health checks and 61 (54.5%) sick cats, presenting systemic clinical signs suggesting CKD, such as weight loss or polyuria/polydipsia, among others.

Results:

Based on UPC, the present study found that 54.5% of all cats included were borderline proteinuric or proteinuric, having increased UPC (UPC ≥ 0.2), with 35.7% included in the sick group and 18.7% in the health-check group. Increased UPC was also statistically associated with azotemia and isosthenuria (urinary-specific gravity between 1,008 and 1,035) in both sick and health-check groups of cats.

Conclusion:

Independent of the reason for their medical visit, it could be concluded that borderline proteinuria and proteinuria were statistically mainly related to CKD in cats. Furthermore, the measurement of UPC could be very useful in the detection and management of CKD in apparently healthy cats during a medical visit for annual health check irrespective of the age.

Evaluation of fructosamine concentration as an index marker for glycaemic control in diabetic dogs

BACKGROUND

Although fructosamine is a commonly used surrogate marker to assess glycaemic control in diabetic dogs, its diagnostic accuracy has been questioned. The main objective of this study was to evaluate the reliability of fructosamine measurements to diagnose well and poorly controlled diabetes mellitus (DM), using continuous glucose monitoring as a gold standard.

METHODS

Twenty-four dogs with treated DM and continuous glucose monitoring for mean (±SD) 13.1 (±1.7) days were retrospectively analysed. Two assessment strategies were applied to categorize glycaemic control, and fructosamine concentrations were determined shortly after sensor cessation using a colorimetric assay.

RESULTS

Correlations of individual fructosamine concentrations with mean glucose as well as percentage of measurements > 15 mmol/L were not significant (p = 0.372, p = 0.129). Fructosamine did not differ between dogs with and without hypoglycaemic episodes (p = 0.64). Receiver operating characteristic analysis for fructosamine to diagnose either good or poor glycaemic control revealed AUC values of 0.71 (p = 0.025) indicating moderate accuracy, and 0.7 (p = 0.135) indicating AUC is non-discriminatory, respectively. The respective positive likelihood ratios for the optimal cutoffs to identify good (<396 μmol/L) and poor control (>449 μmol/L) were three.

CONCLUSIONS

Fructosamine measurement is an imperfect surrogate marker for classifying glycaemic control in diabetic dogs and can only complement serial glucose measurements.

Assessment of postprandial hyperglycemia and circadian fluctuation of glucose concentrations in diabetic dogs using a flash glucose monitoring system

BACKGROUND

Postprandial hyperglycemia (PPH) and circadian glucose concentration fluctuations recorded in the home environment of dogs with naturally occurring diabetes mellitus (DM) have not been reported.

OBJECTIVES

To determine if a flash glucose monitoring system (FGMS; FreeStyle Libre) can detect PPH and circadian fluctuations in glucose concentrations in dogs with variably controlled DM.

ANIMALS

Fourteen client-owned dogs with DM.

METHODS

Prospective observational study. Interstitial glucose (IG) concentrations measured by the FGMS during a 13-day study period were analyzed.

RESULTS

A total of 17, 446 FGMS IG concentrations were analyzed. For all dogs analyzed together, median IG concentration measured within 30 (288 mg/dL), 60 (286 mg/dL), 90 (285 mg/dL), and 120 (285 mg/dL) minutes of meals was each significantly higher than the median IG concentration at all other times (260 mg/dL, 259 mg/dL, 258 mg/dL, and 257 mg/dL, respectively; range, 40-500 mg/dL; P < .001 for each). Median night-time IG concentration measured from all dogs on 3,547 samples recorded between 1:00 am and 6:00 am (268 mg/dL; range, 40-500 mg/dL) was significantly higher than median IG measured on 13, 899 samples at all other time points (259 mg/dL; range, 40-500 mg/dL; P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

The FGMS can be used for future studies of PPH and circadian fluctuations of glucose concentrations in dogs with DM in their home environment.

Retinal Diseases of Senior Dogs

Aging consists of a physiological decline of an organism’s functional activity. During the aging process, the structural and functional changes of the retina can be observed. In most cases, progressive vision loss occurs due to the age related changes of the anterior segment. Retinal diseases, characteristic for senior dogs are: retinal detachment, hypertensive chorioretinopathy, sudden acquired retinal degeneration syndrome (SARDS), progressive retinal atrophy (PRA), glaucoma, retinopathy, cystoid degeneration and neoplasms. The examination of the retina in senior dogs is based on: ophthalmoscopic examination, electroretinography, spectral-domain optical coherence tomography (AD-OCT) and if necessary, histopathological examinations. Comprehensive knowledge regarding the senior dog’s health, significantly increases their quality of life.

The Serum and Saliva Proteome of Dogs with Diabetes Mellitus

This study aims to evaluate the changes in salivary and serum proteomes that occur in canine diabetes mellitus type-1 (DM) through a high-throughput quantitative proteomic analysis. The proteomes of 10 paired serum and saliva samples from healthy controls (HC group, n = 5) and dogs with untreated DM (DM group, n = 5) were analyzed using Tandem Mass Tags (TMT)-based proteomic approach. Additionally, 24 serum samples from healthy controls and untreated DM were used to validate haptoglobin in serum. The TMT analysis quantified 767 and 389 proteins in saliva and serum, respectively. Of those, 16 unique proteins in serum and 26 in saliva were differently represented between DM and HC groups. The verification of haptoglobin in serum was in concordance with the proteomic data. Our results pointed out changes in both saliva and serum proteomes that reflect different physiopathological changes in dogs with DM. Although some of the proteins identified here, such as malate dehydrogenase or glyceraldehyde-3-phosphate dehydrogenase, were previously related with DM in dogs, most of the proteins modulated in serum and saliva are described in canine DM for the first time and could be a source of potential biomarkers of the disease. Additionally, the molecular function, biological process, pathways and protein class of the differential proteins were revealed, which could improve the understanding of the disease's pathological mechanisms.

Ultrasonographic assessment of abdominal aortic elasticity in hypertensive dogs

Background

Systemic hypertension (SH) is a persistent and pathological increase in arterial blood pressure (BP). Chronic SH leads to an increase in aortic (Ao) stiffness, and measuring Ao elasticity is useful for estimating Ao stiffness in humans. Currently, no literature in veterinary medicine describes noninvasive assessment of abdominal Ao elasticity in dogs with SH.

Objective

Compare ultrasonographic‐derived abdominal Ao strain (AoSt) between hypertensive (HT) and normotensive (NT) dogs.

Animals

Fifty privately‐owned dogs with clinical signs, conditions, or both potentially associated with SH.

Methods

Prospective observational case‐control study. Aortic stiffness was estimated by calculating AoSt as follows: AoSt = ([AoDs − AoDd]/AoDd) × 100, where AoDs and AoDd are the Ao diameter in systole and in diastole, respectively. Aortic stiffness was calculated from 2 different Ao transverse sections, the first caudal to the left renal artery (K_AoSt), and the second cranial to the external iliac arteries (I_AoSt).

Results

Thirty‐two dogs were included in the HT group and 18 in the NT group. Both K_AoSt and I_AoSt in HT dogs were significantly lower (P < .05) than in NT dogs (7.4 ± SD 3.6) vs 10.3 (±3.8) and 5.7 (interquartile range [IQR], 3.9‐7.5) vs 8.1 (IQR, 7‐10.3), respectively. Only K_AoSt was significantly influenced by age.

Conclusions and Clinical Importance

Ultrasonographic Ao elasticity assessment was feasible to compare HT and NT dogs. Results indicated that K_AoSt and I_AoSt indices can be used to assess SH‐related Ao stiffness, especially when indirect BP measurements are inconsistent or inaccurate. Additional studies to assess the AoSt in healthy dogs of various ages are needed.

Prevalence and risk factors associated with systemic hypertension in dogs with spontaneous hyperadrenocorticism

Background

Systemic hypertension (SH) is common in dogs with hyperadrenocorticism (HAC) however there are not many studies assessing its prevalence and risk factors.

Objectives

To determine the prevalence and severity of SH in dogs with HAC and its association with clinical and laboratory findings to identify potential risk factors.

Animals

Sixty‐six client owned dogs with spontaneous HAC.

Methods

Retrospective cross‐sectional study. Medical records of dogs with HAC were reviewed. Systolic blood pressure (SBP) was measured using Doppler ultrasonography. Clinical signs, physical examination findings and clinicopathologic data (CBC, serum biochemistry and electrolytes, urinalysis and urinary culture, and adrenal function tests) were reviewed for analysis.

Results

Prevalence of SH (≥150 mm Hg) was 82% (54/66) and prevalence of severe SH (≥180 mm Hg) was 46% (30/66). All dogs with thrombocytosis had SH (P = .002), and a platelet count ≥438 × 10³/μL was 100% specific and 61.1% sensitive to predict SH (AUC = .802, P = .001). Median potassium levels were lower in hypertensive dogs (4.1 mEq/L, range 3.1‐5.4 mEq/L) than in normotensive ones (4.5 mEq/L, range 4.0‐5.0 mEq/L) (P = .007). Dogs with UPC ≥ 0.5 had higher median SBP than those without proteinuria (P = .03). Dogs with concurrent diabetes mellitus seemed to have a reduced risk of SH (OR = .118, 95%CI = .022‐.626, P = .02).

Conclusions and Clinical Importance

Systemic hypertension is common in dogs with HAC and is frequently severe. Blood pressure should be routinely assessed in these dogs, especially if thrombocytosis, proteinuria or low potassium concentrations are present.

Effects of treatment with lispro and neutral protamine Hagedorn insulins on serum fructosamine and postprandial blood glucose concentrations in dogs with clinically well-controlled diabetes mellitus and postprandial hyperglycemia

OBJECTIVE

To assess effects of basal-bolus insulin treatment (BBIT) with lispro and neutral protamine Hagedorn (NPH) insulins, compared with NPH insulin alone, on serum fructosamine concentration (SFC) and postprandial blood glucose concentration (BGC) in dogs with clinically well-controlled diabetes mellitus and postprandial hyperglycemia fed a high insoluble fiber-content diet.

ANIMALS

6 client-owned dogs with diabetes mellitus.

PROCEDURES

Blood samples were collected for BGC and SFC measurement in hospitalized dogs just before feeding and routine SC NPH insulin administration (time 0); samples were collected for BGC measurement every 30 minutes for 2 hours, then every 2 hours for up to 10 additional hours. Postprandial hyperglycemia was identified when BGC 30 minutes after insulin administration exceeded BGC at time 0 or the 1-hour time point. For BBIT, owners were instructed to continue NPH insulin administration at the usual dosage at home (q 12 h, with feeding) and to administer lispro insulin (0.1 U/Kg, SC) separately at the time of NPH injections. Two weeks later, SFC and BGC measurements were repeated; results at the start and end of the study were compared statistically.

RESULTS

Median SFC was significantly higher at the start (400 μmol/L) than at the end (390 μmol/L) of the study. Median 1-hour (313 mg/dL) and 1.5-hour (239 mg/dL) BGC measurements at the start of the study were significantly higher than those at the end of the study (117 and 94 mg/dL, respectively).

CONCLUSIONS AND CLINICAL RELEVANCE

In this sample of dogs with well-controlled diabetes mellitus, addition of lispro insulin to an existing treatment regimen of NPH insulin and dietary management significantly decreased postprandial BGCs. Further study of BBIT for dogs with diabetes mellitus is warranted.

Exploratory analysis of anti-insulin antibodies in diabetic dogs receiving recombinant human insulin

OBJECTIVES

To quantify anti-insulin antibodies in diabetic dogs treated with recombinant human insulin and to determine if insulin dosage or duration of treatment differed between anti-insulin antibody-positive and -negative diabetic dogs.

MATERIALS AND METHODS

Descriptive preliminary study using serum from 24 client-owned diabetic dogs treated for a minimum of 2 weeks with recombinant human insulin, and 24 client-owned healthy control dogs without diabetes. Sera were analysed by radioimmunoassay for anti-insulin antibodies. The proportion of antibody positive dogs was compared between groups by Fisher's exact test.

RESULTS

Four diabetic (16.6%) and no control dogs were anti-insulin antibody positive.

CLINICAL SIGNIFICANCE

These results indicate that treatment with recombinant human insulin may induce anti-insulin antibodies in dogs, although this finding needs to be re-investigated in a larger study to investigate the impact of anti-insulin antibodies on glycaemic control.

The effect of the sodium-glucose cotransporter type-2 inhibitor dapagliflozin on glomerular filtration rate in healthy cats

Sodium-glucose cotransporter type-2 inhibitors (SGLT2is) reduce glomerular hyperfiltration in diabetic people with early diabetic nephropathy. The objective of this report was to assess changes in glomerular filtration rate in healthy cats after treatment with a SGLT2i. Eight healthy research adult castrated male cats were used in a randomized, controlled, cross-over study design. We induced isolated renal tubular glucosuria by dosing cats with the SGLT2i dapagliflozin. The cats received by mouth 10 mg dapagliflozin or control every 24 h in each of the 4, 5-d trial periods that were separated by a 7-d washout period. We assessed glomerular filtration rate (iohexol clearance method), serum urea, creatinine, symmetric dimethylarginine, and 24-h sodium and chloride urinary excretion on the fifth day of each trial period. We analyzed the data with a mixed linear model that included the fixed effects of treatment (treated and control) and trial period, and the random effect of the cat. Compared with controls, cats treated with dapagliflozin had a significant increase in mean (±SE) glomerular filtration rate (3.1 ± 0.2 vs 2.5 ± 0.2 mL/kg/min; P = 0.01), whereas there were no significant differences in serum urea, creatinine and symmetric dimethylarginine, and 24-h urine sodium and chloride excretion. We propose that dapagliflozin-mediated delivery of sodium and glucose distal from the proximal convoluted tubule induced compensatory increased sodium absorption at the thick ascending loop of Henle that resulted in decreased sodium delivery to the distal tubule leading to tubuloglomerular feedback-mediated glomerular hyperfiltration. Future studies should determine if SGLT2is' renoprotective effect in people can be enhanced with the addition of a Na⁺-K⁺-Cl^- diuretic and whether dapagliflozin will be useful in mitigating proteinuria and hypertension that follow glomerular hyperfiltration in diabetic companion animals in a similar mechanism as in people.

ACVIM consensus statement: Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats

An update to the 2007 American College of Veterinary Internal Medicine (ACVIM) consensus statement on the identification, evaluation, and management of systemic hypertension in dogs and cats was presented at the 2017 ACVIM Forum in National Harbor, MD. The updated consensus statement is presented here. The consensus statement aims to provide guidance on appropriate diagnosis and treatment of hypertension in dogs and cats.

Optical coherence tomography and molecular analysis of sudden acquired retinal degeneration syndrome (SARDS) eyes suggests the immune-mediated nature of retinal damage

Objective

To perform detailed analysis of retinal changes in dogs with SARDS using optical coherence tomography (OCT), funduscopy, and molecular analysis.

Animals

Subjects were 29 dogs from 12 US states and Canada diagnosed with SARDS by 8 ophthalmologists. An additional 7 eyes from 5 deceased SARDS dogs were used for molecular and histological analysis.

Procedures

Dogs were evaluated using chromatic pupil light reflex testing (cPLR), and electroretinography (ERG); subjects underwent complete ophthalmic examination, including funduscopy, retinal photography, and OCT, in addition to complete laboratory analysis, blood pressure evaluation, abdominal and thoracic radiographs, and computerized tomography (CT) imaging to assess possible systemic abnormalities. Histology and immunohistochemistry analysis was performed in 2 SARDS eyes. Microarray analysis was performed in 5 SARDS retinas.

Results

Thirty‐eight percent of patients had <1‐mm wide retinal detachments (RD) on OCT analysis, which could not be detected by funduscopy or retinal photographs. Systemic hypertension did not seem to be a contributing factor (RD 22.2%; ND 20%, Odds ratio = 1.1). No dogs showed neoplastic changes by thoracic or abdominal radiography, or CT imaging. There was no statistically significant difference in age (RD 7.9 ± 1.9 years (mean ± SD); ND 7.6 ± 1.7 years, p = 0.69) or duration of blindness prior to presentation (RD 18 ± 7 days (mean±SD); ND 21 ± 12 days, p = 0.28). Microarray and histology analysis of SARDS eyes revealed molecular changes suggestive of immune‐mediated damage.

Conclusions

Observed histological, molecular, and OCT changes are highly suggestive of immune‐mediated damage in SARDS eyes.

Canine Diabetes Mellitus Associated Ocular Disease

Diabetes mellitus (DM) is a commonly encountered disease in companion animal veterinary practice. Ocular complications in dogs with DM are thought to be common but there are no reports of the overall incidence of DM-associated ocular disease. Some complications, such as cataracts and ocular surface disease, can lead to vision loss and significant morbidity among DM patients, therefore early recognition and intervention are essential for successful outcomes. The purpose of this article is to provide a review of several currently known or suspected ocular diseases associated with DM.

Abnormal renovascular resistance in dogs with diabetes mellitus: correlation with glycemic status and proteinuria

Present study was conducted with the objectives of determining the renal vascular resistance in dogs with diabetes mellitus and to study the correlation between the indices of renovascular resistance with glycemic status, systolic blood pressure (SBP) and proteinuria in dogs with diabetes mellitus. This study was conducted on seventeen diabetic dogs and ten apparently healthy dogs. Increased renal resistive index (RI) and pulsatility index (PI) were observed in diabetic dogs as compared to healthy dogs. Systemic hypertension and proteinuria were observed in 10 and 3 out of 17 diabetic dogs, respectively. Significant positive correlation was observed between the indices of renovascular resistance and fasting blood glucose levels and between the indices of renovascular resistance and serum glycated hemoglobin levels. No correlation was observed between the indices of renovascular resistance and SBP as well as the indices of renovascular resistance and proteinuria. As the indices of renovascular resistance correlate significantly with glycemic status, they can be used as the early marker for kidney damage in diabetic patients. Among these indices renal PI was found to be more sensitive than renal RI.

Spectrophotometry and Ultracentrifugation for Measurement of Plasma Lipids in Dogs with Diabetes Mellitus

Background

There are conflicting reports of plasma lipoprotein lipid content in dogs with diabetes mellitus (DM).

Objectives

To determine lipoprotein lipid content of plasma of dogs with DM by spectrophotometry and ultracentrifugation; to compare lipoprotein lipid content in diabetic and healthy dogs; and to quantify apolipoprotein B‐100 (ApoB) in dogs with DM.

Animals

22 dogs with DM and 9 healthy dogs.

Methods

Cross‐sectional study. Triglyceride (TG), total cholesterol (TC), and high‐density lipoprotein cholesterol (HDL‐C) concentrations were measured by spectrophotometry. Very low‐density lipoprotein cholesterol (VLDL‐C) and low‐density lipoprotein cholesterol (LDL‐C) concentrations were calculated after ultracentrifugation. Non‐HDL‐C cholesterol was calculated by subtracting HDL‐C from TC. ApoB was quantified by ELISA. The Mann‐Whitney test was used for comparison of median lipoprotein concentrations, and Spearman's correlation was used to assess associations between ApoB and lipoprotein fractions.

Results

All values are reported in mg/dL. Median TG (122), TC (343.5), HDL‐C, (200), VLDL‐C, (27) LDL‐C (68), non‐HDL‐C (114), and ApoB (320) were significantly higher in dogs with DM, compared to healthy dogs (57, 197, 168, 12, 16, 31, and 258, respectively, P‐values 0.0079, <0.001, 0.029, 0.011, <0.001, <0.001, 0.025, respectively). A significant association was found between ApoB and LDL‐C (Spearman's rho = 0.41, P = 0.022) and between ApoB and non‐HDL‐C (Spearman's rho = 0.40, P = 0.027).

Conclusions and Clinical Importance

Dyslipidemia of dogs with DM is characterized by pronounced increases in LDL‐C and non‐HDL‐C concentrations, although all lipoprotein fractions are significantly increased. Knowledge of specific lipoprotein fraction alterations in dogs with DM can enhance treatment options for diabetic dyslipidemia in dogs.

Clinical Consequences of Hypertriglyceridemia-Associated Proteinuria in Miniature Schnauzers

BACKGROUND

Primary hypertriglyceridemia is a common condition in older Miniature Schnauzers that recently has been associated with proteinuria and underlying glomerular pathology, particularly glomerular lipid thromboemboli. Consequences of glomerular disease can include hypertension, thromboembolic disease, and cardiac disease. The incidence of these sequelae in Miniature Schnauzers with hypertriglyceridemia-associated proteinuria (HTGP) is unknown.

OBJECTIVE

To investigate prevalence of hypertension, decreased antithrombin III activity, and cardiac disease in Miniature Schnauzers with and without HTGP.

ANIMALS

Thirty-two Miniature Schnauzers ≥7 years old.

METHODS

Prospective case-control study. Data collected from dogs included a CBC, biochemistry panel, urinalysis, urine protein-to-creatinine ratio, urine cortisol-to-creatinine ratio, serum total thyroxine concentration, fasting serum triglyceride concentration, indirect blood pressure, antithrombin III activity, and serum cardiac troponin I concentration. Results from dogs with HTGP (serum triglyceride concentration ≥ 100 mg/dL and urine protein-to-creatinine ratio >0.5) were statistically compared to normotriglyceridemic, nonproteinuric dogs.

RESULTS

Eighteen of the 32 dogs (56%) had primary hypertriglyceridemia. Of those dogs, 8 of 18 had proteinuria. None of the HTGP dogs were azotemic or hypoalbuminemic. Serum albumin concentration, alkaline phosphatase activity, and cholesterol concentration were significantly increased in dogs with HGTP compared to those without HGTP. No increased risk of hypertension, decreased antithrombin III activity, or cardiac disease was noted. Limited data from 8 dogs with HTGP showed no development of hypoalbuminemia or azotemia over a median follow-up period of 18 months.

CONCLUSIONS AND CLINICAL IMPORTANCE

Geriatric Miniature Schnauzers with HGTP may have a good prognosis overall, and are not typically azotemic or hypoalbuminemic.

Untargeted metabolomic analysis in naturally occurring canine diabetes mellitus identifies similarities to human Type 1 Diabetes

While predominant as a disease entity, knowledge voids exist regarding the pathogenesis of canine diabetes. To test the hypothesis that diabetic dogs have similar metabolomic perturbations to humans with type 1 diabetes (T1D), we analyzed serum metabolomic profiles of breed- and body weight-matched, diabetic (n = 6) and healthy (n = 6) dogs by liquid chromatography-mass spectrometry (LC-MS) profiling. We report distinct clustering of diabetic and control groups based on heat map analysis of known and unknown metabolites. Random forest classification identified 5/6 dogs per group correctly with overall out of bag error rate = 16.7%. Diabetic dogs demonstrated significant upregulation of glycolysis/gluconeogenesis intermediates (e.g., glucose/fructose, C6H12O6, keto-hexose, deoxy-hexose, (P < 0.01)), with significant downregulation of tryptophan metabolism metabolites (e.g., picolinic acid, indoxyl sulfate, anthranilate, (P < 0.01)). Multiple amino acids (AA), AA metabolites, and bile acids were also significantly lower in diabetic versus healthy dogs (P < 0.05) with the exception of the branched chain AA valine, which was elevated in diabetic animals (P < 0.05). Metabolomic profiles in diabetic versus healthy dogs shared similarities with those reported in human T1D (e.g., alterations in glycolysis/gluconeogensis metabolites, bile acids, and elevated branched chain AA). Further studies are warranted to evaluate the utility of canine diabetes to provide novel mechanistic insights to the human disorder.

HEMOGLOBINA GLICADA E FRUTOSAMINA EM CÃES COM DIABETES MELLITUS

Resumo O Diabetes mellitus (DM) ocorre com frequência em cães, sendo a glicemia o teste laboratorial de confirmação. O diagnóstico e monitoramento em pessoas são realizados pelas concentrações de hemoglobina glicada e frutosamina. O objetivo deste estudo foi diagnosticar a DM em 19 cães, com avaliação das concentrações da glicose sérica, hemoglobina glicada e frutosamina. Seis cães com DM e em tratamento com insulina foram acompanhados por um período de doze meses, com as mesmas avaliações hematológicas, até o óbito (três cães) ou controle glicêmico (três cães). Observouse aumento dos valores de glicose, hemoglobina glicada e frutosamina em todos os cães com DM, e valores de hemoglobina glicada e glicose superiores nos animais não sobreviventes, na última avaliação realizada. Estes resultados apontam para a importância da avaliação de hemoglobina glicada e frutosamina em cães com diabetes e para diagnóstico e controle da efetividade do tratamento.

Comparison between Urine Protein: Creatinine Ratios of Samples Obtained from Dogs in Home and Hospital Settings

Background

The urine protein:creatinine ratio (UPC) is used to quantify urine protein excretion and guide recommendations for monitoring and treatment of proteinuria.

Hypothesis/Objectives

Home urine samples will have lower UPCs than hospital samples. The objectives were to compare UPCs of samples collected in each setting and to determine whether environment of sample collection might affect staging, monitoring or treatment recommendations.

Animals

Twenty‐four client‐owned dogs.

Methods

Prospective, nonmasked study. Clients collected a urine sample from their dog at home and a second sample was collected at the hospital. Dogs receiving corticosteroids or angiotensin‐converting enzyme inhibitors were excluded, as were those with urine samples of inadequate volume, no protein on dipstick analysis, or active urine sediment. Samples were refrigerated after collection, dipstick and sediment evaluations were completed and each sample was frozen at −80°C within 12 hours. UPCs were performed on frozen samples within 2 months.

Results

From 81 paired samples, 57 were excluded. Of the remaining 24, 12/24 (50%) had higher hospital sample UPCs, 9/24 (38%) had identical UPCs, and 3/24 (12%) had lower hospital UPCs. The UPCs of hospital samples were higher than home samples for the total population (P = .005) and the subset with UPC > 0.5 (P = .001).

Conclusions

Setting and related circumstances of urine collection in dogs is associated with UPC differences; results are usually higher in hospital than in home samples. This difference has the potential to affect clinical interpretation.