Positive Coombs' test results in two dogs treated with amiodarone.

Effects of amiodarone, an antiarrhythmic drug that is effective in suppressing severe ventricular arrhythmias that are refractory to other antiarrhythmic drugs, were evaluated in 2 dogs with cardiac disease. One dog was a Doberman Pinscher with cardiomyopathy that developed severe thrombocytopenia after receiving amiodarone for 7 months. The second was a Giant Schnauzer with acquired mitral valve degeneration that developed regenerative anemia after receiving amiodarone for 5 months. Results of direct Coombs' tests were positive in both dogs. Adverse effects of amiodarone are numerous; in dogs, the most common adverse effects are anorexia and hepatotoxicosis. Frequent CBC and serum biochemical analyses should be performed when amiodarone is administered with the intent of continuing the drug indefinitely.