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

416 reports to the FDA describe application site reaction in dogs given Ivermectin + Pyrantel. That is 0.3% of all reports for this medicine, compared with 0.4% across reports for all dog medicines.

416Reports

68%Marked serious

27%Recovered

1.2%Died or euthanised

33 daysTypical onset

How soon it started

Same day

34 17%

1–2 days

23 11%

3–7 days

12 6.0%

1–4 weeks

21 10%

Over a month

111 55%

How the animals did

Recovered

111 27%

Still unwell when reported

28 6.7%

Died

3 0.7%

Euthanised

2 0.5%

Not known

272 65%

Problems reported at the same time

Itching

106 25%

Hair loss

77 19%

Restlessness or agitation

54 13%

52 13%

30 7.2%

24 5.8%

24 5.8%

Hair coat discolouration

22 5.3%

Age of the animals

Under 1 year

1–3 years

113

4–7 years

141

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 application site reaction in dogs?: 416 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 33 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).

Application site reaction with similar medicines

Application site reaction after Milbemycin Oxime + Praziquantel (Interceptor Plus) 39 reports · 0.1% of its reports
Application site reaction after Selamectin (Revolution) 1,056 reports · 3.6% of its reports
Application site reaction after Ivermectin (Heartgard) 23 reports · 0.2% of its reports

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