Text Box: symptoms (bloody diarrhea) with rapid death secondary to myocarditis.  The pathologist concluded that Trifexis had no part in the death of the puppies.  
	Of course, like many internet rumors this has taken on a life of its own and despite the complete lack of any supportive evidence is now circulating as “fact”.  Many people have chimed in with anecdotal reports of problems with their pets that they think might be related.
	In fact, on my vet computer network which links thousands of vets and their hundreds of thousands of patients or more, none of us has had a death we attribute to Trifexis.  We do see some dogs vomit after taking the pill, which is an inconvenience, and a very few have mild lethargy for a day.  I am very cautious to question clients about seizure history as there is some evidence that Trifexis   may lower the threshold to trigger seizures in epileptic dogs, and there certainly are some drug interactions which need to be considered.  However, the consensus is that over millions of doses, the drug has been quite safe in our hands.  In my practice, we have used milbemycin, the ingredient which prevents heartworm, for well over 20 years with no Text Box: 	Recently on the internet there have been rumors and postings of issues with safety of Trifexis, which is our heartworm prevention containing a flea preventative as well.  There are claims of three puppies from a litter in Atlanta which died “after using Trifexis”.  The other puppies in the litter which did not receive it survived.  Should you be concerned?
	First, let’s look at the time frame.  Two of the puppies died 3 weeks after taking the Trifexis, the third puppy 6 days.  In both cases, we would expect to see side effects much sooner if they were to occur.  The three puppies shared genetics, as well as a common environment for most of their lives and likely common exposure to many environmental factors such as diet, vaccines, etc.  
	Secondly, the necropsy (autopsy) reports on all three puppies indicated they died of myocarditis or endocarditis, which is inflammation of the lining of the heart.  This is not a known side effect of Trifexis.  In Georgia, in dogs of this age, parvo virus, lyme disease, or trypanosomiasis all are infectious diseases which would be high on the list of likely causes.  In fact, trypanosomiasis has been on the upswing in the south and the most common symptom is sudden onset of parvo-like Text Box: problems, and spinosad, the flea killing ingredient, for five years with virtually no problems. 
	My patients’ safety is our primary concern.  With any new drug that comes out, unless we have a pressing need for it I try to wait a year to see if any problems arise (and we did this when Comfortis, the flea-only version of Trifexis became available).  We also try to get a complete history to avoid any of the contraindications.  And as time goes on, sometimes we find that we are not satisfied with safety of some products and we remove them from our shelves.  For example, this happened the the injectable heartworm prevention called Proheart, which we used for a short time.  I was not happy with  some of the safety reports I was hearing and we pulled it from our inventory after less than a year.  Shortly thereafter, it was pulled from the market (though it has returned, I still feel it’s problems outweigh its advantages so we elected not to restock it).  And it is important to also remember that ALL drugs have side effects and potential to cause harm, but still can be very beneficial.  I can assure you my own pets are on Trifexis and I have not lost any sleep over their safety.  I truly believe it is an extremely safe product.  
Text Box: Trifexis Safety...do I need to worry?