Felycin-CA1 [fel-i-sin C-A-1], or sirolimus [si-ro·-li-​mus] delayed release tablets, recently received conditional approval for the management of ventricular hypertrophy [high-PER-trō-fee] in cats with subclinical hypertrophic cardiomyopathy, or HCM.

Cardiomyopathy is a disease of the heart muscle, and HCM causes thickening of the heart’s left ventricle — that’s the lower left chamber of the heart, which pumps blood out to most of the body. HCM is a progressive disease that’s one of the most common causes of feline deaths. Cats with subclinical disease have thickening of the left ventricle but are not showing clinical signs.

Conditional approval may be granted if a drug addresses a serious or life-threatening disease and clinical trials would be especially difficult to implement.

Felycin-CA1 [fel-i-sin C-A-1] is only available by prescription from a veterinarian.