Death after Ivermectin + Praziquantel in horses

The FDA has received 88 reports of death in horses after Ivermectin + Praziquantel. That is 3.3% of all reports for this medicine, compared with 11% across reports for all horse medicines, so it is reported less often than average with this medicine.

88Reports

32%Marked serious

0.0%Recovered

98%Died or euthanised

Same dayTypical onset

How soon it started

Same day

13 52%

1–2 days

5 20%

3–7 days

3 12%

1–4 weeks

2 8.0%

Over a month

2 8.0%

How the animals did

Died

75 85%

Euthanised

11 13%

Not known

2 2.3%

Problems reported at the same time

23 26%

20 23%

17 19%

16 18%

13 15%

Didn't work as expected

11 13%

Digestive tract disorder

10 11%

Fever

10 11%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Ivermectin prevents heartworm disease (monthly). Praziquantel treats tapeworms.

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 Ivermectin + Praziquantel cause death in horses?: 88 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).

Death with similar medicines

Death after Moxidectin (ProHeart 6) 177 reports · 13% of its reports
Death after Ivermectin (Heartgard) 156 reports · 23% of its reports
Death after Moxidectin + Praziquantel 47 reports · 13% of its reports

All reported side effects of Ivermectin + Praziquantel in horses · Medicines most reported with death