Fatal pulmonary hemorrhage associated with vascular amyloid deposition in a cat

Case summary

An adult female spayed Siamese-cross cat of unknown age was presented for bilateral hemorrhagic otorrhea. Nasopharyngeal polyps were diagnosed by CT and biopsy; bilateral ventral bulla osteotomies were performed. Episodic epistaxis, otic hemorrhage and hemoptysis with respiratory distress progressed over 18 months. Systolic blood pressure, complete blood count, plasma biochemistries, prothrombin time, partial thromboplastin time and coagulation factor 12, 9 and 8 activities were normal. Serial thoracic radiographs revealed patchy interstitial to alveolar patterns. Airway hemorrhage prevented diagnostic bronchoscopy. Respiratory hemorrhage was ultimately fatal. Amyloid deposition was identified in pulmonary vasculature, bronchial wall, lymphoid tissues, nasal-pharyngeal tissue and tympanic bullae based on microscopic examination and confirmed by Congo red staining with green birefringence under polarized light.

Relevance and novel information

Amyloidosis should be considered as a differential diagnosis in cats with spontaneous hemorrhage of the respiratory or otic tracts. Although systemic amyloidosis is associated with a grave prognosis, this case suggests that prolonged survival is possible after the initial onset of signs in cats with pulmonary amyloidosis.

Effects of various factors on Doppler ultrasonographic measurements of radial and coccygeal arterial blood pressure in privately owned, conscious cats

OBJECTIVE To assess the effects of age, body condition score (BCS), and muscle condition score (MCS) on radial and coccygeal systolic arterial blood pressure (SAP) in cats. DESIGN Prospective randomized trial. ANIMALS 66 privately owned cats enrolled between May and December 2010. PROCEDURES BCS and MCS of cats were assessed by 2 investigators; SAP was measured via Doppler ultrasonic flow detector, with cats positioned in right lateral or sternal recumbency for measurements at the radial or coccygeal artery, respectively, with order of site randomized. Associations among variables were assessed through correlation coefficients, partial correlation coefficients, and ANCOVA. RESULTS Interrater reliability for BCS and MCS assessment was high (correlation coefficients, 0.95 and 0.83, respectively). No significant effect was identified for order of SAP measurement sites. Coccygeal and radial SAP were positively correlated (ρ = 0.45). The median difference in coccygeal versus radial SAP was 19 mm Hg, but differences were not consistently positive or negative. Radial SAP was positively correlated with age (ρ = 0.48) and negatively correlated with MCS (ρ = -0.30). On the basis of the correlation analysis, the association between radial SAP and MCS reflected the confounding influence of age. Coccygeal SAP was not significantly correlated with age, BCS, or MCS. CONCLUSIONS AND CLINICAL RELEVANCE Use of the coccygeal artery is recommended to reduce the confounding effects of age and sarcopenia on Doppler ultrasonographic SAP measurements in cats. Additionally, monitoring for changes in MCS is recommended for cats undergoing serial SAP measurement.

Effects of various factors on Doppler flow ultrasonic radial and coccygeal artery systolic blood pressure measurements in privately-owned, conscious dogs

OBJECTIVE

The purpose of this study was to assess the effects of age, body condition score (BCS) and muscle condition score (MCS) on indirect radial and coccygeal Doppler systolic arterial blood pressure (SAP) measurements in dogs.

METHODS

Sixty-two privately-owned dogs were enrolled between June and July 2016. The BCS and MCS were determined by two investigators. Blood pressure was measured per published guidelines and using headphones, and the order of measurement site was randomized. Dogs were positioned in right lateral recumbency for radial measurements and sternal recumbency or standing for coccygeal measurements. Associations between SAP and other variables were assessed by correlation coefficients and analysis of covariance.

RESULTS

Radial and coccygeal SAP measurements were moderately correlated (r = 0.45, P < 0.01). Radial SAP measurements were higher than coccygeal SAP measurements (mean difference 9 mmHg, P < 0.01), but discordance occurred in both directions. No difference was observed between the first measurement taken, the average of measurements 2-6, or the average of all 6 measurements for either the radial (128, 129, and 129 mmHg; P = 0.36) or coccygeal (121, 122, and 122 mmHg; P = 0.82) site. Associations were not found between SAP measurements for either site and age, weight, BCS, MCS, anxiety score, or cuff size. Heart rate decreased significantly from the start of acclimation to the end of the first data collection series regardless of site (P < 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

Initial measurement site can be based on patient and operator preference given lack of associations with patient variables, but the same site should be used for serial SAP measurements given discordant results between sites.

Posaconazole Pharmacokinetics in Healthy Cats after Oral and Intravenous Administration

BACKGROUND

Posaconazole is the most active available azole antifungal drug, but absorption and pharmacokinetics are not available to guide dosing regimens in cats.

OBJECTIVE

To determine the pharmacokinetics of posaconazole in cats given an IV solution and PO suspension.

ANIMALS

Six healthy, adult research cats.

METHODS

After a 12-hour fast, each cat received 15 mg/kg of posaconazole PO suspension with food. Four cats also received 3 mg/kg IV posaconazole after a 7-day washout period. Plasma was collected at predetermined intervals for analysis using high-pressure liquid chromatography (HPLC). Concentration data were analyzed using a 2-compartment pharmacokinetic analysis for IV administration data and a 1-compartment analysis with first-order input for PO administration data using Phoenix® software.

RESULTS

After IV dosing, volume of distribution (VSS ) was 1.9 (0.3) L/kg (mean, standard deviation), terminal half-life (T½ ) was 57.7 (28.4) hours, and clearance was 28.1 (17.3) mL/kg/h. After PO dosing, peak concentration (CMAX ) was 1.2 (0.5) μg/mL and T½ was 38.1 (15.0) hours. Bioavailability of PO suspension was 15.9% (8.6). No adverse effects were observed with either route of administration.

CONCLUSION AND CLINICAL IMPORTANCE

Despite low PO absorption, these data allow for simulation of PO dosage regimens that could be explored in clinical studies. Two regimens can be considered to maintain targeted trough concentrations of 0.5-0.7 μg/mL as extrapolated from studies in humans: (1) 30 mg/kg PO loading dose followed by 15 mg/kg q48h, or (2) 15 mg/kg PO loading dose followed by 7.5 mg/kg q24h.

Serum cortisol concentrations in dogs with pituitary-dependent hyperadrenocorticism and atypical hyperadrenocorticism

Background

Atypical hyperadrenocorticism (AHAC) is considered when dogs have clinical signs of hypercortisolemia with normal hyperadrenocorticism screening tests.

Hypothesis/Objectives

To compare cortisol concentrations and adrenal gland size among dogs with pituitary‐dependent hyperadrenocorticism (PDH), atypical hyperadrenocorticism (AHAC), and healthy controls.

Animals

Ten healthy dogs, 7 dogs with PDH, and 8 dogs with AHAC.

Method

Dogs were prospectively enrolled between November 2011 and January 2013. Dogs were diagnosed with PDH or AHAC based on clinical signs and positive screening test results (PDH) or abnormal extended adrenal hormone panel results (AHAC). Transverse adrenal gland measurements were obtained by abdominal ultrasound. Hourly mean cortisol (9 samplings), sum of hourly cortisol measurements and adrenal gland sizes were compared among the 3 groups.

Results

Hourly (control, 1.4 ± 0.6 μg/dL; AHAC, 2.9 ± 1.3; PDH, 4.3 ± 1.5) (mean, SD) and sum (control, 11.3 ± 3.3; AHAC, 23.2 ± 7.7; PDH, 34.7 ± 9.9) cortisol concentrations differed significantly between the controls and AHAC (P < .01) and PDH (P < .01) groups. Hourly (P < .01) but not sum (P = .27) cortisol concentrations differed between AHAC and PDH dogs. Average transverse adrenal gland diameter of control dogs (5.3 ± 1.2 mm) was significantly less than dogs with PDH (6.4 ± 1.4; P = .02) and AHAC (7.2 ± 1.5; P < .01); adrenal gland diameter did not differ (P = .18) between dogs with AHAC and PDH.

Conclusions and Clinical Importance

Serum cortisol concentrations in dogs with AHAC were increased compared to controls but less than dogs with PDH, while adrenal gland diameter was similar between dogs with AHAC and PDH. These findings suggest cortisol excess could contribute to the pathophysiology of AHAC.

Canine pancreatic-specific lipase concentrations in clinically healthy dogs and dogs with naturally occurring hyperadrenocorticism

Background

Specificity of canine pancreatic lipase immunoreactivity (cPLI) assays in dogs with hyperadrenocorticism (HAC) is unknown.

Hypothesis

Results of cPLI assays differ for clinically healthy dogs and dogs with HAC.

Animals

Seventeen healthy dogs and 20 dogs with HAC diagnosed by ACTH stimulation test results without evidence of clinical pancreatitis.

Methods

Dogs were enrolled between December 2009 and November 2010. Serum cPLI concentrations were determined by quantitative (Spec cPL test, SPEC) and semiquantitative (SNAP cPL test, SNAP) assays. Results were categorized as normal, equivocal, or abnormal (SPEC) or negative or positive (SNAP). Associations between group and cPLI were assessed using Fisher's exact test or the Mann–Whitney U‐test. Spearman rank correlation coefficients (ρ) were determined for SNAP and SPEC results. Significance was set at P < .05.

Results

Spec cPL test concentrations were significantly (P < .001) higher in dogs with HAC (491.1 μg/L) than in healthy dogs (75.2 μg/L), with more abnormal SPEC results in HAC dogs (P < .001). There were more (P = .002) positive SNAP results in dogs with HAC (55%) than in healthy dogs (6%). SNAP and SPEC results were highly correlated (ρ = 0.85; P < .001).

Conclusions and Clinical Importance

Dogs with HAC had higher SPEC concentrations and more positive SNAP results than clinically healthy dogs with normal ACTH stimulation test results. Specificity of SPEC and SNAP assays in HAC dogs without clinical pancreatitis were 65 and 45%, respectively. Pending further study, SNAP and SPEC results should be interpreted cautiously in dogs with HAC to avoid false diagnosis of concurrent pancreatitis.

Bioequivalence of orally administered generic, compounded, and innovator-formulated itraconazole in healthy dogs

Background

Itraconazole is commonly used to treat systemic fungal infections in dogs, but problems exist with absorption and cost.

Objective

To determine oral bioequivalence of generic and compounded itraconazole compared to original innovator (brand name) itraconazole in healthy dogs.

Animals

Nine healthy, adult research Beagle dogs.

Methods

A randomized, 3‐way, 3‐period, crossover design with an 8‐day washout period. After a 12‐hour fast, each dog received 100 mg (average: 10.5 mg/kg) of either innovator itraconazole, an approved human generic capsule, or compounded itraconazole (compounded using a commercially available compounding vehicle) with a small meal. Plasma was collected at predetermined intervals for high pressure liquid chromatography analysis. Concentration data were analyzed using noncompartmental pharmacokinetics to determine area under the curve (AUC), peak concentration (C_MAX), and terminal half‐life. Bioequivalence tests compared generic and compounded itraconazole to the reference formulation.

Results

Average ratios of compounded and generic formulations to the reference formulation of itraconazole for AUC were 5.52% and 104.2%, respectively, and for C_MAX were 4.14% and 86.34%, respectively. A test of bioequivalence using 2 one‐sided tests and 90% confidence intervals did not meet bioequivalence criteria for either formulation.

Conclusion and Clinical Importance

Neither generic nor compounded itraconazole is bioequivalent to the reference formulation in dogs. However, pharmacokinetic data for generic formulation were similar enough that therapeutic concentrations could be achieved. Compounded itraconazole produced such low plasma concentrations, it is unlikely to be effective; therefore, compounded itraconazole should not be used in dogs.

Associations among albuminuria, C-reactive protein concentrations, survival predictor index scores, and survival in 78 critically ill dogs

BACKGROUND

Microalbuminuria and C-reactive protein (CRP) are predictors of morbidity and survival in critically ill human patients.

HYPOTHESIS/OBJECTIVES

To evaluate results of microalbuminuria assays (untimed single-sample urine albumin concentration [U-ALB] and the urine albumin:creatinine ratio [UACR]), serum CRP, and survival predictor index (SPI2) scores as predictors of survival in critically ill dogs.

ANIMALS

Seventy-eight dogs admitted to intensive care units at University of Tennessee (UT) and Colorado State University (CSU).

METHODS

Prospective observational study. Critically ill dogs were eligible for enrollment, unless euthanized because of financial constraints. Samples were collected within 3 hours of admission. Spearman's rank-correlation coefficients were determined for U-ALB, UACR, CRP, and SPI2. U-ALB, UACR, CRP, and SPI2 were assessed for associations with 7- and 30-day survival by Mann-Whitney U-tests and receiver operating characteristic (ROC) curves. P-values < .0125 were considered significant.

RESULTS

UT (n = 49) and CSU (n = 29) patients did not differ significantly. Forty percent (31/78) of dogs died. SPI2 was inversely correlated with U-ALB (r(s) = -0.39, P < .001) and UACR (r(s) = -0.41, P < .001). CRP was not correlated with SPI2 (P = .019), U-ALB (P > .1), or UACR (P > .1). U-ALB and UACR had very high correlation (r(s) = 0.95, P < .001). SPI2, U-ALB, and UACR differed significantly for survivors and nonsurvivors. SPI2, U-ALB, and UACR had areas under the ROC curve (AUC) from 0.68 to 0.74 for survival prediction.

CONCLUSIONS AND CLINICAL IMPORTANCE

Albuminuria and SPI2, but not CRP, are associated with survival in critically ill dogs. Suboptimal AUCs limit the value of microalbuminuria testing for clinical risk assessment. Additional studies are necessary to determine the usefulness of microalbuminuria testing in patient risk stratification for prospective research.

Comparison of various methods for estimating body fat in dogs

Obesity is considered one of the most common forms of malnutrition occurring in dogs. Laboratory methods of evaluation of body composition in live dogs have included dual-energy X-ray absorptiometry (DEXA) and deuterium oxide (D(2)O) dilution. Clinical methods of evaluation include assigning a body condition score (BCS) based on visual observation, palpation, and morphometric measurements. This study used these four methods to evaluate 23 healthy, adult, client-owned dogs. Good correlation (coefficient of determination [r(2)]=0.78) was found between measurements of percent body fat (%BF) determined by the D(2)O dilution method and the DEXA scan. Percent body fat can also be estimated using BCS (r(2)=0.92 comparison with DEXA) or by using morphometric measurements with simple calculations (r(2)=0.92 comparison with DEXA).

Segmental tracheal dysplasia in a mixed breed dog

A 6-month-old, spayed female, mixed breed dog was referred for respiratory difficulty. Radiographic and bronchoscopic evaluations showed tracheal narrowing from the thoracic inlet to its bifurcation. Under anesthesia, the trachea ruptured and the dog died. Microscopic evaluation revealed underlying segmental tracheal and bronchial cartilaginous malformation (dysplasia).

Putative transmission of Mycobacterium tuberculosis infection from a human to a dog

A 3.5-year-old Yorkshire Terrier was evaluated for anorexia and vomiting; infection with Mycobacterium tuberculosis was diagnosed by use of histology, bacteriologic culture, and polymerase chain reaction (PCR) assay on various tissues. The dog was living with a human with an established M. tuberculosis infection. Findings were unique in that diagnosis of M. tuberculosis infection was obtained via PCR techniques, and isolates from the owner and dog were matched via restriction fragment length polymorphism fingerprinting. Dogs infected with M. tuberculosis from humans are most commonly infected via the respiratory tract. Clinical signs in dogs are variable and depend on the integrity of the immune system and the degree of dissemination. Diagnosis can often be obtained through histopathology and bacteriologic culture; additional diagnostic techniques are also available. Treatment of a dog with confirmed M. tuberculosis infection is controversial, and at least 6 months of multidrug treatment is required.

Complications of ileal cannulation in cats

BACKGROUND AND PURPOSE

The anatomic position of the ileum is such that use of simple, noninvasive sampling techniques is difficult. Sampling of ileal contents by use of a cannula provides information about those contents-digestibility and fermentation patterns; however, complications with use of cannulas in horses and dogs have been reported. Therefore, cats were chosen as a laboratory model in which to study ileal cannulation.

METHODS

Simple T-piece cannulas were surgically placed in the ileum of six adult cats.

RESULTS

Postsurgical complications included cannula displacement and leakage, with subsequent abscessation and skin inflammation. Owing to these complications, the cannulas were removed from four of the six cats. Similar complications developed after removal of the cannulas. In the only attempt to collect a sample, obtaining a 0.5-ml sample of ileal fluid from one cannula took 3 h. Of the six cats, four died or were euthanized.

CONCLUSION

Use of cannulas is not a viable technique of collecting ileal fluid samples in cats.

Pharmacological relaxation of the urethra in male cats: a study of the effects of phenoxybenzamine, diazepam, nifedipine and xylazine

Urethral pressure profiles (UPPs) were recorded in ten adult healthy male cats before and after administration of either phenoxybenzamine, diazepam, nifedipine or xylazine. A significant decrease (p less than 0.05) in urethral pressure at the level of the prostate was observed following treatment with all drugs. Xylazine produced a significant decrease in urethral pressure 4 to 7 cm from the tip of the penis in healthy male cats. None of the drugs used decreased urethral pressure in the zones of pure striated muscle or pure smooth muscle in these cats, making current recommendations for pharmacological management of urethral spasm suspect. Further studies are necessary to evaluate clinical cases of urethral spasm and to study the effects of these drugs on the urethral pressure of cats suffering from this spasm.