Interceptor Side Effects

Interceptor is one of the leading prescription medications for parasites in dogs and cats. Interceptor prevents deadly heartworm disease, plus protects dogs and cats from roundworms, hookworms, and whipworms (in dogs). Dogs and cats are tested for the presence of heartworms. If heartworms are present, they must be treated. Then either Interceptor or some other heartworm preventative is prescribed. As with any drug, there is a risk of side effects. In a small percentage of dogs, digestive and neurological side effects may occur. Side effects in cats are rarely seen.

  1. Adverse Reactions in Dogs

    • Mild, temporary reactions in some treated dogs who carry a large number of parasites include difficulty breathing, vomiting, heavier than normal salivation, lethargy or lack of energy. These reactions are presumed to be due to parasite die-off as the worms die inside the dogs, and the toxins from the decaying worm tissue makes the dogs sick. Other noted side effects include depression, anorexia (lack of appetite), diarrhea (loose stools), convulsions and weakness.

    Safety Concerns in Dogs

    • According to the July 2008 issue of Vet Parasitol, two trials have been conducted to determine the safety and efficacy of Interceptor for dogs. Interceptor has been tested as safe in over 75 different dog breeds. It is safe for pregnant dogs and puppies over 2 weeks of age. Puppies younger than 2 weeks old should not take Interceptor. The main ingredient in Interceptor has been shown to be safe in dog shampoos, flea collars and vaccines; however, treated dogs with high parasite count experience mild reactions. Also, high doses of Interceptor given to pregnant and nursing dogs results in measurable amounts of the drug in the mother's milk. Puppies drinking this milk demonstrated side effects from the drug. However, puppies drinking the milk of mothers who were treated at the recommended dosage of Interceptor showed no ill effects from the drug.

      According to DailyMed at the National Institute of Health, rough-coated collies also showed adverse reactions when overdosed with Interceptor, but showed no such reactions when given the drug at the recommended dosage.

    Interceptor and Cats

    • The safety of Interceptor has not been completely established for cats, although the drug is available for felines. The drug should not be used for kittens less than 6 weeks old. Interceptor has been tested as safe for eight cat breeds. No adverse effects have been recorded for cats at either normal or high dosages.