Submitted by Veterinary Wellness Partners on Thu, 04/17/2014 - 12:27pm

There are a lot of products on the market available to prevent heartworm disease in dogs.  Many of these also combine intestinal parasite control.  In this article, we are going to highlight Trifexis, a combination product that we highly recommend.

  • To begin with, Trifexis is a once a month pill that is marketed as heartworm and flea prevention.  It is manufactured by Elanco and combines several medications to achieve its broad range of protection. Spinosad is the flea control medicine, while Milbemycin Oxime provides the heartworm and intestinal parasite control.  The chewable tablets come in a range of sizes to cover the various sizes of different dog breeds, from the 5 pound Chihuahua to the 120 pound Rottweiler.  

What does Trifexis actually cover?

  • Heartworm disease:  Like all heartworm prevention on the market, Trifexis kills the first stage of the heartworms. This occurs before any damage can be done.  It is vital to kill this stage, as the other stages can not be treated.  The other stages also can not be prevented nor detected until 6 months after the original infection.  
  • Roundworms:  This is the most common type of intestinal parasite, infecting nearly every young puppy. Roundworms are contagious to people, especially the young and immunocompromised.
  • Hookworms:  Hookworms are the second most common parasite.  They can also infect humans, making hookworms another zoonotic risk.
  • Whipworms:  Whipworms are a little less common than the parasites that are listed above, but prevention is critical. Once whipworms establish themselves in the soils, the worms are difficult to get rid of.
  • Fleas:  Combining flea control with the other parasite control is what makes Trifexis a very unique product.  Unlike Sentinel, Trifexis actually kills the adult flea.  It begins working within 30 minutes and achieves a 100% kill rate after four hours.

In order to be effective, Trifexis should be administered once a month, all year round.  This is due to two factors. The first is that the weather in Wayne County and Northeast Ohio is so variable that parasites remain active longer than we would like to think.  The second reason is that some of the parasites have an extended life cycle.  This means that simply "deworming" at the sign of the first frost is not enough to keep the parasites at bay. For more information, please feel free to call one of our staff members at the Orrville Veterinary Clinic.  Our phone number is (330)682-2971 and our email address is   We will also try to have links to other products that are similar to Trifexis.

Article written and submitted by Dr. Jeffrey R. Fink on behalf of Orrville Veterinary Clinic, Inc.