Liver problems after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) in dogs

The FDA has received 149 reports of liver problems in dogs after Ivermectin + Praziquantel + Pyrantel. That is 1.7% of all reports for this medicine, compared with 4.6% across reports for all dog medicines, so it is reported less often than average with this medicine.

149Reports

62%Marked serious

30%Recovered

12%Died or euthanised

Same dayTypical onset

How soon it started

Same day

57 68%

1–2 days

12 14%

3–7 days

1 1.2%

1–4 weeks

5 6.0%

Over a month

9 11%

How the animals did

Recovered

44 30%

Still unwell when reported

8 5.4%

Died

13 8.7%

Euthanised

5 3.4%

Not known

79 53%

Problems reported at the same time

86 58%

59 40%

34 23%

33 22%

Didn't prevent heartworm

23 15%

Seizures

19 13%

Pale mucous membrane

19 13%

Death

17 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. Pyrantel treats roundworms and hookworms.

Products with this combination include Iverhart Max. 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 Ivermectin + Praziquantel + Pyrantel cause liver problems in dogs?: 149 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).

Liver problems with similar medicines

Liver problems after Ivermectin + Pyrantel (Heartgard Plus) 1,518 reports · 1.0% of its reports
Liver problems after Milbemycin Oxime + Spinosad (Trifexis) 2,221 reports · 1.7% of its reports
Liver problems after Moxidectin (ProHeart 6) 2,025 reports · 4.0% of its reports
Liver problems after Milbemycin Oxime + Praziquantel (Interceptor Plus) 534 reports · 1.7% of its reports
Liver problems after Milbemycin Oxime (Interceptor) 531 reports · 1.8% of its reports
Liver problems after Selamectin (Revolution) 560 reports · 1.9% of its reports
Liver problems after Ivermectin (Heartgard) 369 reports · 3.1% of its reports
Liver problems after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 63 reports · 5.4% of its reports

All reported side effects of Ivermectin + Praziquantel + Pyrantel in dogs · Medicines most reported with liver problems