Immune-mediated polyarthritis and anterior uveitis secondary to zonisamide administration in a dog with refractory epilepsy.

The objective of this article is to describe a case of suspected zonisamide-induced immune-mediated polyarthritis (IMPA) and anterior uveitis in a dog. A 7-year-old male neutered Siberian Husky with a history of refractory idiopathic epilepsy was presented for cluster seizures. Following the addition of zonisamide to the antiepileptic regime, the dog developed new IMPA and anterior uveitis. Within a few weeks of discontinuation of the zonisamide, the dog's IMPA and anterior uveitis resolved. These immune-mediated conditions were thus presumed to be an idiosyncratic reaction to zonisamide. To our knowledge, this is the first report of IMPA and anterior uveitis in dogs associated with zonisamide administration at its recommended dose.

Acute kidney injury from presumptive intramural ureteral hemorrhage secondary to diphacinone rodenticide exposure in a dog.

OBJECTIVE: To describe the clinical features and outcome of a dog with anticoagulant rodenticide (diphacinone) exposure, which was subsequently diagnosed with a coagulopathy characterized by hemoperitoneum, and presumptive ureteral wall hemorrhage contributing to acute kidney injury (AKI). CASE SUMMARY: A 4-year-old, female neutered Australian Cattle Dog was evaluated for an acute onset of lethargy, decreased appetite, and a mild right thoracic limb lameness. Radiographs and point of care ultrasound demonstrated retroperitoneal and peritoneal effusion. Diagnostic abdominocentesis confirmed hemorrhagic effusion. Complete blood count, biochemistry, and coagulation profile showed a regenerative anemia (PCV 32%), thrombocytopenia (platelets 96 × 109 /L [96 × 103 /µl]), azotemia (BUN 38.9 mmol/L [109 mg/dl], creatinine 512.8 µmol/L [5.8 mg/dl]), and coagulopathy (prothrombin time >100 s, activated partial thromboplastin time >42.3 s). The client reported access to anticoagulant rodenticide up to 72 hours prior to presentation. Ultrasonographic examination revealed bilateral pyelectasia and hydroureter with thickened distal ureteral walls at the level of the ureteral-vesicular junctions. The ultrasonographic conclusion was presumptive intramural ureteral hemorrhage resulting in ureteral obstruction. The patient was diagnosed with AKI with likely prerenal, renal, and postrenal components. Treatment included vitamin K and frozen plasma transfusion. The patient recovered fully and was discharged 3 days after presentation. Two days after discharge, the patient had improvement in azotemia (BUN 10.7 mmol/L [30 mg/dl], creatinine 176.6 µmol/L [2.0 mg/dl]). Gas chromatography-mass spectrometry confirmed presence of diphacinone in the blood. Repeat ultrasound and biochemistry 60 and 210 days, respectively, after discharge showed resolution of ureteral wall thickening, hydroureter, pyelectasia, and recovery of kidney parameters. NEW OR UNIQUE INFORMATION: Although nephropathies secondary to anticoagulant therapy have been described in people, the authors believe this is the first report of diphacinone anticoagulant rodenticide exposure contributing to an AKI secondary to obstruction from ureteral wall hemorrhage in the veterinary literature.

Successful treatment of 5-fluorouracil toxicosis with hemodialysis.

OBJECTIVE: To describe the successful treatment of lethal dose 5-fluorouracil (5-FU) toxicosis using hemodialysis. CASE SUMMARY: A 4-month-old intact female Golden Retriever was presented to the emergency department after ingesting 20 g of 5% 5-FU cream. The puppy developed refractory seizures and became comatose with uncontrolled tonic-clonic convulsions. Because of the low molecular weight and minimal protein binding of 5-FU, a single hemodialysis treatment was employed for detoxification. The puppy improved clinically posttreatment and was successfully discharged 3 days after admission. Postingestion leukopenia and neutropenia occurred but were responsive to treatment with filgrastim. The puppy is neurologically normal and has no lasting effects 1 year postingestion. NEW OR UNIQUE INFORMATION PROVIDED: To the authors' knowledge, this is the first reported case in veterinary medicine of a potentially fatal 5-FU ingestion that has been treated with intermittent hemodialysis.

Presumptive renal tubular acidosis secondary to topiramate administration in a cat.

OBJECTIVE: To describe renal tubular acidosis (RTA) and secondary acquired hyperaldosteronism in a cat as an adverse effect of topiramate therapy. CASE SUMMARY: An 8-year-old neutered female cat on chronic oral topiramate therapy at a recommended dose (11.9 mg/kg q 8 h) for seizure control was presented with severe metabolic acidosis and hypokalemia. Plasma electrolyte and acid-base analysis identified a severe metabolic acidosis (pH 7.153, reference interval: 7.31-7.46), hypokalemia (2.08 mmol/L [2.08 mEq/L], reference interval: 3.5-4.8 mmol/L [3.5-4.8 mEq/L]), and ionized hypercalcemia (1.85 mmol/L [1.85 mEq/L], reference range: 1.1-1.4 mmol/L [1.1-1.4 mEq/L]). Urinalysis revealed a urine specific gravity of 1.021 and a pH of 7.0. Diagnostic workup suggested distal RTA as a cause of the cat's acid-base and electrolyte disturbances. Aldosterone concentration was moderately increased, suggestive of secondary hyperaldosteronism. The metabolic abnormalities resolved with supportive care and discontinuation of topiramate. NEW OR UNIQUE INFORMATION PROVIDED: Topiramate is suggested to have led to the development severe RTA in a cat.

Clinical application of the StatSensor and StatSensor Xpress point-of-care creatinine measurement devices in dogs.

BACKGROUND: Creatinine is a universally important blood parameter used to detect and monitor acute and chronic kidney disease. Reliable measurements at the bedside remain a challenge in human and veterinary medicine. Despite its potential, a trustworthy point-of-care creatinine biosensor has yet to be established. OBJECTIVES: We aimed to determine the precision and accuracy of the StatSensor (SS) and StatSensor Xpress (SSX) handheld creatinine measurement devices in dogs. METHODS: Paired creatinine samples from dogs with normal (creatinine ≤159 µmol/L), moderate (159-354 µmol/L), and marked (>354 µmol/L) azotemia were compared with a commercial enzymatic analyzer. Within-day precision and linearity studies were performed prior to method comparison studies. Method comparison was evaluated using Bland-Altman, concordance correlation coefficient, Deming, and Passing-Bablok regression analysis. RESULTS: Seventy-eight dogs were enrolled in the study, including 28 (35%), 25 (32%), and 26 (33%) with normal, moderate, and marked azotemia. Total error surpassed recommendations for all devices, and linearity deviated from identity for the SS1 and SS2. The concordance correlation coefficients of the SS1, SS2, SSXI, and SSX2, were 0.69, 0.59, 0.82, and 0.44, respectively. Bland-Altman analyses showed a high variation in the differences, and relationships showed high heteroskedasticity with negative systemic bias among high creatinine concentrations. CONCLUSIONS: Neither the SS and SSX are considered acceptable for clinical applications in dogs. Further research is indicated for the development of a reliable, cost-effective, point-of-care creatinine analyzer to improve the rapid detection and monitoring human and veterinary patients.

Effect of time until sample analysis on lactate in dogs with shock.

INTRODUCTION: Lactate concentrations can increase with hypoperfusion in dogs and could be used as a prognostic indicator in sick dogs. In a busy emergency service, sample evaluation could be delayed. However, sample evaluation delays have been shown to cause lactate concentration increases in healthy dogs. In sick dogs, the magnitude of increased lactate is unknown. The goal of this study was to prospectively evaluate the effect of room temperature storage times on lactate measurements in dogs presenting to an emergency service. METHODS: We evaluated the precision and accuracy of the NOVA Lactate Plus, using standard procedures. To assess the impact of time on lactate concentrations in sick dogs, we prospectively enrolled dogs presenting to an emergency service. Lactate concentrations were measured at six time points using samples stored at room temperature. A Friedman test, followed by a Wilcoxon rank test with a Bonferroni correction was used to evaluate time points. RESULTS: Forty-five dogs were enrolled in this prospective observational study. The Lactate Plus and table-top analyzer compared favorably, with an R2 of .98, and a mean bias of 0.26 in 50 canine samples. Precision was acceptable, with a percent coefficient of variation of 5.39. Statistically significant increases in lactate concentrations were found at all time points over baseline (P = .008). CONCLUSIONS: In as little as 7.5 minutes, lactate concentrations increased significantly in samples stored at room temperature. Dogs with lower initial lactate concentrations had had higher increases in lactate concentration percentages over 90 minutes.