A suspected case of digitalis toxicity secondary to therapeutic management of congestive heart failure in a Boerboel dog

A 15 months old male Boerboel, weighing 25kg presented to Veterinary Teaching Hospital, Abeokuta, Nigeria, with complaint of abdominal distention, emaciation and anorexia was diagnosed of congestive heart failure (CHF) of unknown etiology. At presentation, prominent S- wave voltages in lead II, III electrocardiogram, a positive R-wave in lead AVR and a mean electrical axis of -900 suggestive of right ventricular enlargement were evident. A right atrial enlargement was also suspected due to the presence of a tented P-wave on the electrocardiogram. Digoxin was administered at 0.01 mg/kg orally, once daily to increase cardiac contractility and reduce heart rate; Enalapril given at 0.5 mg/kg orally once daily was to blunt the renin angiotensin aldosterone response, Furosemide at 2mg/kg orally, once daily was administered to increase natriuresis and diuresis. After 2 weeks of medication the dogs exhibited signs of digitalis toxicity such as ventricular premature contraction, ventricular tachycardia. This case is a rare occurrence and has not been reported in our veterinary clinics. The management of CHF with standard dose regime of digitalis requires therapeutic drug monitoring as it could result in breed specific toxicity.