Trifexis in the News…


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No doubt you may heard the recent buzz about Trifexis in the news and may have some questions.

We are aware of the recent media attention being given to Trifexis, a heartworm, flea and parasite prevention product developed by Elanco. As a product that we recommend for our patients we felt it was important to, once again, investigate the claims and make a medical decision about the safety of this popular product.

Let us begin by emphasizing that the FDA has reviewed these claims and found no link between the use of Trifexis and the death of these patients. It is important to understand how the FDA addresses these claims of adverse drug effects. A pet owner can simply call the FDA to report an adverse event and state that a product was the cause of death. Local media have indicated that approximately 965 pet owners across the country have made this claim. These claims have not been confirmed and even those that are confirmed with a different cause of death, remain on this preliminary list.

Trifexis contains Spinosad and Milbemycin, two compounds that have been on the market for a number of years. Spinosad, used to control fleas and the primary compound in Comfortis, has been on the market since 2006. The only significant side-effect reported has been vomiting. Milbemycin is the antiparasitic that prevents heartworm disease, and has been on the market since the 1990s. It is also the primary ingredient in other popular prevention products (Interceptor and Sentinel). These products have been used safely with few reported side effects, especially deaths, since that time.

While we believe that individual pets can have an adverse reaction to any medication, these unexpected reactions are unforeseeable and not an indication that the product is unsafe for all pets. It is the professional opinion of our Veterinarians, based on the information available, that Trifexis is a safe and effective product. We will continue to recommend Trifexis for our patients and most of our team members use Trifexis for their own pets.

If you feel that your pet has had an adverse reaction to Trifexis, immediately contact your Veterinarian. Elanco, the maker of Trifexis, welcomes your feedback about adverse reactions and includes information for reporting to the FDA.

For more information about Trifexis or to report and adverse event visit: