Pain after Ivermectin + Pyrantel (Heartgard Plus) in dogs

The FDA has received 330 reports of pain in dogs after Ivermectin + Pyrantel. That is 0.2% of all reports for this medicine, compared with 0.7% across reports for all dog medicines, so it is reported less often than average with this medicine.

330Reports

49%Marked serious

29%Recovered

9.4%Died or euthanised

18 daysTypical onset

How soon it started

Same day

47 26%

1–2 days

25 14%

3–7 days

8 4.4%

1–4 weeks

26 14%

Over a month

74 41%

How the animals did

Recovered

93 28%

Recovered with lasting effects

3 0.9%

Still unwell when reported

34 10%

Died

15 4.5%

Euthanised

16 4.8%

Not known

169 51%

Problems reported at the same time

120 36%

80 24%

62 19%

60 18%

48 15%

45 14%

36 11%

Restlessness or agitation

36 11%

Age of the animals

Under 1 year

1–3 years

102

4–7 years

8–11 years

12+ years

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 pain in dogs?: 330 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 18 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).

Pain with similar medicines

Pain after Milbemycin Oxime + Spinosad (Trifexis) 572 reports · 0.4% of its reports
Pain after Moxidectin (ProHeart 6) 436 reports · 0.9% of its reports
Pain after Milbemycin Oxime + Praziquantel (Interceptor Plus) 129 reports · 0.4% of its reports
Pain after Milbemycin Oxime (Interceptor) 121 reports · 0.4% of its reports
Pain after Selamectin (Revolution) 159 reports · 0.5% of its reports
Pain after Ivermectin (Heartgard) 63 reports · 0.5% of its reports

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