Liver problems after Ivermectin + Pyrantel (Heartgard Plus) in dogs

1,518 reports to the FDA describe liver problems in dogs given Ivermectin + Pyrantel. That is 1.0% 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.

1,518Reports

57%Marked serious

16%Recovered

16%Died or euthanised

14 daysTypical onset

How soon it started

Same day

137 18%

1–2 days

109 14%

3–7 days

74 9.8%

1–4 weeks

148 20%

Over a month

288 38%

How the animals did

Recovered

173 11%

Recovered with lasting effects

68 4.5%

Still unwell when reported

308 20%

Died

117 7.7%

Euthanised

125 8.2%

Not known

727 48%

Problems reported at the same time

591 39%

482 32%

440 29%

275 18%

266 18%

237 16%

178 12%

174 11%

Age of the animals

Under 1 year

116

1–3 years

330

4–7 years

400

8–11 years

408

12+ years

230

About this medicine

Ivermectin prevents heartworm disease (monthly). Pyrantel treats roundworms and hookworms.

Products with this combination include Heartgard Plus, Tri-Heart Plus, Iverhart Plus. 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 + Pyrantel cause liver problems in dogs?: 1,518 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 14 days 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 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 Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 149 reports · 1.7% of its reports
Liver problems after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 63 reports · 5.4% of its reports

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