All medications have side effects and drug companies are required to list them even if one animal out of the entire trial suffered from a given side effect. Trifexis is commonly known to cause vomiting. The majority of the time this vomiting can be alleviated if the pill is given with a meal; many medications are tolerated better when given with food. Occasionally we have a patient who can not tolerate it and we recommend to use another of the many heartworm and flea options.
As for the case reported on the news, there were two common ingredients. One was Trifexis and the other was genetics. The three puppies who died came from the same litter. So which is the culprit? Honestly, I don't know. The findings on a necropsy suggest the deaths of all three puppies were heart related. No other documented cases of heart problems associated with Trifexis use are known.
The bottom line is that an owner and their veterinarian should decide which product is best suited for the patient. Age, weight, and other drugs taken should be strongly considered. I find Trifexis to be a very effective product while at the same time a safe product, with minimal side effects. I will continue to prescribe Trifexis for the use of heartworm prevention and flea treatment. For more information on Trifexis, visit the Elanco website at http://www.trifexis.com/.