Positive Coombs' test results in two dogs treated with amiodarone

Effects of amiodarone, an antiarrhythmic drug that is effective in suppress ing severe ventricular arrhythmias that are refractory to other antiarrhyth mic drugs, were evaluated in 2 dogs with cardiac disease. One dog was a Dob erman Pinscher with cardiomyopathy that developed severe thrombocytopenia a fter receiving amiodarone for 7 months. The second was a Giant Schnauzer wi th acquired mitral valve degeneration that developed regenerative anemia af ter 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 advers e effects are anorexia and hepatotoxicosis. Frequent CBC and serum biochemi cal analyses should be performed when amiodarone is administered with the i ntent of continuing the drug indefinitely.