Weight loss after Pyrantel in horses

The FDA has received 28 reports of weight loss in horses after Pyrantel. That is 3.0% of all reports for this medicine, compared with 1.4% across reports for all horse medicines, so it is reported unusually often with this medicine.

28Reports

7.1%Marked serious

0.0%Recovered

3.6%Died or euthanised

–Typical onset

How the animals did

Died

1 3.6%

Not known

27 96%

Problems reported at the same time

Didn't work as expected

7 25%

Loss of condition

5 18%

Lethargy

3 11%

Loss of appetite

3 11%

Blood problems

2 7.1%

Restlessness or agitation

2 7.1%

Didn't stop worms

2 7.1%

Abdominal pain

2 7.1%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Pyrantel treats roundworms and hookworms.

Questions owners ask

Can Pyrantel cause weight loss in horses?: 28 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.
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 Pyrantel in horses · Medicines most reported with weight loss