Updated On September 23rd, 2025
Pet's info: Dog | Coton de Tulear | Male | unneutered | 1 year and 9 months old | 10 lbs
My pet is due for his 2nd dose of Heartgard on 3/5. When I gave it to him on 2/5 he had loose stool for a week going multiple times throughout the day and evening. I am afraid to give it again and I purchased 6 months worth of medication. Is there a chance it could have just been because it was a new medication and now he will be ok?
1 Answer
Published on March 3rd, 2020
I suggest you give him the Heartgard. The benefits of him ingesting the Heartgard far outweigh the risks (some loose stools). If you give it this time and it happens again then you can pretty much assume the Heartgard is the cause and then you can speak to your vet about using a different product like a topical (Revolution or Advantage Multi). You can sometimes minimize GI upset by giving the Heartgard with a full meal.
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