Pseudohyperkalemia in horses with rhabdomyolysis reported by an enzymatic chemistry analyzer.

OBJECTIVE: To investigate pseudohyperkalemia occurring in horses experiencing rhabdomyolysis when serum chemistry profiles are run on an VetScan VS2 analyzer (Abaxis). ANIMALS: 18 horses with rhabdomyolysis (creatine kinase [CK] > 1,000 U/L). METHODS: In 3 horses with serum CK activities > 5,800 U/L and persistent serum potassium concentrations of > 8.5 mmol/L (VetScan VS2), potassium concentrations were reevaluated with either i-STAT Alinity Base Station (Abbott), Catalyst (Idexx), or Cobas c501 (Roche) ion-specific analyzers. Paired serum samples from 15 additional horses (median serum CK activity, 7,601 U/L; range, 1,134 to 192,447 U/L) were analyzed on both VetScan VS2 and Cobas c501 machines. Serum potassium concentrations were compared between the VetScan VS2 and ion-specific analyzers by Bland-Altman and Wilcoxon ranked tests and correlated to log10 CK activity via Pearson correlation. RESULTS: Serum potassium concentrations were significantly higher on the VetScan VS2 (6.7 ± 1.6 mmol/L) versus the ion-specific analyzers (4.0 ± 1.1 mmol/L; P < .0001), with high bias shown in Bland-Altman analysis (43.1 ± 27.9). Potassium concentrations positively correlated with log10 CK activity with the VetScan VS2 (R2 = 0.51; P = .003) but not the Cobas (R2 = 0.09; P = .3) analyzer. CLINICAL RELEVANCE: An alternate analyzer to the VetScan VS2 should be used to evaluate serum potassium concentrations in horses with rhabdomyolysis because the VetScan VS2 methodology uses lactate dehydrogenase, which increases in serum with rhabdomyolysis and falsely elevates potassium concentrations.

Babesia vulpes in a dog from Prince Edward Island, Canada.

A 12-year-old neutered male American Staffordshire terrier dog was referred to the Atlantic Veterinary College, Prince Edward Island, Canada, for suspected immune-mediated hemolytic anemia. Babesiosis (Babesia vulpes) was confirmed using polymerase chain reaction testing. The dog was successfully treated with a 10-day protocol of atovaquone/proguanil (TEVA Pharmaceutical Industries, Toronto, Ontario), 13.5 mg/kg BW, PO, q8h and azithromycin (Pharmascience, Montreal, Quebec), 10 mg/kg BW, PO, q24h. To the authors' knowledge, this report is the first documented case of babesiosis caused by Babesia vulpes in a dog from Canada.

Babesia vulpes chez un chien de l'Île-du-Prince-Édouard, Canada. Un chien American Staffordshire terrier mâle castré de 12 ans a été référé au Atlantic Veterinary College, Île-du-Prince-Édouard, Canada, pour suspicion d'anémie hémolytique à médiation immunitaire. La babésiose (Babesia vulpes) a été confirmée à l'aide d'un test d'amplification en chaîne par la polymérase. Le chien a été traité avec succès avec un protocole de 10 jours d'atovaquone/proguanil (TEVA Pharmaceutical Industries, Toronto, Ontario), 13,5 mg/kg BW, PO, q8h et azithromycine (Pharmascience, Montréal, Québec), 10 mg/kg BW, PO, q24h. À la connaissance des auteurs, ce rapport est le premier cas documenté de babésiose causée par Babesia vulpes chez un chien du Canada.(Traduit par Dr Serge Messier).

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Zinc-induced hemolytic anemia in a dog caused by ingestion of a game-playing die.

A 16-month-old spayed female mixed breed dog was presented with a 1-week history of anorexia, lethargy, diarrhea, vomiting, and difficulty rising. Hematologic evaluation indicated a marked macrocytic hypo-chromic, markedly regenerative anemia. A metallic foreign object in the gastrointestinal tract was identified on abdominal radiographs. Serum zinc concentration was markedly increased.

Granulocytic anaplasmosis in a horse from Nova Scotia caused by infection with Anaplasma phagocytophilum.

A 16-year-old Paint stallion was presented with intermittent fever, inappetance, lethargy, icterus, distal limb edema, and submandibular lymphadenopathy. The horse was native to Nova Scotia and had never left that province. Morulae were detected in granulocytes. Ananaplasma phagocytophilum infection was confirmed by serology and polymerase chain reaction (PCR). The horse responded to treatment with oxytetracycline.