Ask The Vet

Provided By: Melissa McKee DVM

Allergic reactions in general have a similar appearance. The most common manifestations include rash or hives, swollen lower limbs and eyelids, salivation, and in severe cases respiratory collapse. Choke is not a reported reaction to ivermectin, but if a horse does not swallow the wormer and instead holds it in his mouth, extreme salivation resembling choke can be seen. Sometimes there is an ivermectin-sensitive parasite that lives in the skin of the abdominal area, which can die off and cause brief local swelling after administration of the dewormer. In addition, Ivermectin is a very safe drug and accidental overdose would be very difficult to achieve.