Ivermectin is an anti-parasite medication given to dogs to prevent heartworm disease and to treat various other parasite-related conditions like demodectic and sarcoptic mange, and ear mites.
The most common side effects of this drug are relatively mild and include:
- Lack of appetite
Every dog should be tested for heartworms prior to administration of ivermectin, because dogs already invaded by microfilaria (heartworms at the larval stage of development) can have a serious reaction to the medication.
In those dogs, ivermectin can cause a fatal side effect characterized by symptoms of shock including vomiting, hypothermia and depression.
Ivermectin has also been associated with a central nervous system event in some dogs which leads to loss of coordination, seizures, and in some cases, death.
Researchers at Washington State University's College of Veterinary Medicine have discovered that certain dog breeds are more sensitive to some drugs, including ivermectin, than other breeds. This drug sensitivity results from a mutation in the multi-drug resistance gene (MDR1).