Injection site reaction after Ivermectin + Pyrantel (Heartgard Plus) in dogs

The FDA has received 301 reports of injection site reaction in dogs after Ivermectin + Pyrantel. That is 0.2% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

301Reports

51%Marked serious

19%Recovered

1.7%Died or euthanised

24 daysTypical onset

How soon it started

Same day

19 8.9%

1–2 days

19 8.9%

3–7 days

17 8.0%

1–4 weeks

69 32%

Over a month

89 42%

How the animals did

Recovered

55 18%

Recovered with lasting effects

1 0.3%

Still unwell when reported

56 19%

Died

2 0.7%

Euthanised

3 1.0%

Not known

184 61%

Problems reported at the same time

67 22%

46 15%

42 14%

37 12%

27 9.0%

Didn't prevent heartworm

19 6.3%

Neutrophilia

18 6.0%

Fever

18 6.0%

Age of the animals

Under 1 year

1–3 years

111

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 injection site reaction in dogs?: 301 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 24 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).

Injection site reaction with similar medicines

Injection site reaction after Milbemycin Oxime + Spinosad (Trifexis) 39 reports · 0.0% of its reports
Injection site reaction after Moxidectin (ProHeart 6) 1,295 reports · 2.6% of its reports
Injection site reaction after Milbemycin Oxime + Praziquantel (Interceptor Plus) 110 reports · 0.3% of its reports
Injection site reaction after Milbemycin Oxime (Interceptor) 30 reports · 0.1% of its reports
Injection site reaction after Selamectin (Revolution) 29 reports · 0.1% of its reports
Injection site reaction after Ivermectin (Heartgard) 50 reports · 0.4% of its reports

All reported side effects of Ivermectin + Pyrantel in dogs · Medicines most reported with injection site reaction