Prolonged one stage prothrombin time (ospt) after Moxidectin (ProHeart 6) in dogs
29 reports to the FDA describe prolonged one stage prothrombin time (ospt) in dogs given Moxidectin. That is 0.1% of all reports for this medicine, compared with 0.0% across reports for all dog medicines, so it is reported unusually often with this medicine.
How soon it started
How the animals did
Problems reported at the same time
Age of the animals
About this medicine
Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs).
Products with this ingredient include ProHeart 6, ProHeart 12. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.
Some herding breeds (for example Collies) carry the MDR1 gene variant and can be more sensitive to this drug class at high doses.
Questions owners ask
- Can Moxidectin cause prolonged one stage prothrombin time (ospt) in dogs?
- 29 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
- How soon after a dose was it reported?
- In half of the reports with dates, it started within the same day of the first dose.
- What should I do?
- Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).
All reported side effects of Moxidectin in dogs · Medicines most reported with prolonged one stage prothrombin time (ospt)