Digoxin-specific antibody fragments for the treatment of suspected Nerium oleander toxicosis in a cat

CASE SUMMARY: A 6-year-old castrated male domestic shorthair cat presented for lethargy and gastrointestinal signs after possible exposure to Nerium oleander leaves. The cat developed a ventricular arrhythmia that responded positively to the administration of digoxin-specific antibody fragments. Underlying hypertrophic cardiomyopathy was also diagnosed after the development of congestive heart failure. Humane euthanasia was elected owing to a lack of significant response to continued therapy. RELEVANCE AND NOVEL INFORMATION: To our knowledge, this is the first report to describe the use of digoxin-specific antibody fragments in a cat. Nerium oleander toxicosis is associated with significant morbidity and mortality, and digoxin-specific antibody fragments have been used effectively in humans and animals. The development of cardiac necrosis may have contributed to worsening arrhythmias and highlights the importance of early intervention. The use of digoxin-specific antibody fragments for suspected N oleander toxicosis in a cat resulted in a rapid response and appeared to be well tolerated.