Skin disorders after Ivermectin + Pyrantel (Heartgard Plus) in dogs

The FDA has received 153 reports of skin disorders in dogs after Ivermectin + Pyrantel. That is 0.1% of all reports for this medicine, compared with 0.5% across reports for all dog medicines, so it is reported less often than average with this medicine.

153Reports

63%Marked serious

17%Recovered

3.3%Died or euthanised

28 daysTypical onset

How soon it started

Same day

12 15%

1–2 days

11 14%

3–7 days

8 10%

1–4 weeks

14 18%

Over a month

34 43%

How the animals did

Recovered

21 14%

Recovered with lasting effects

5 3.3%

Still unwell when reported

20 13%

Died

2 1.3%

Euthanised

3 2.0%

Not known

102 67%

Problems reported at the same time

40 26%

21 14%

20 13%

18 12%

Skin rash or irritation

16 10%

Didn't stop fleas

16 10%

Didn't work as expected

16 10%

Diarrhea

14 9.2%

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). 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 skin disorders in dogs?: 153 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 28 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).

Skin disorders with similar medicines

Skin disorders after Milbemycin Oxime + Spinosad (Trifexis) 576 reports · 0.4% of its reports
Skin disorders after Moxidectin (ProHeart 6) 50 reports · 0.1% of its reports
Skin disorders after Milbemycin Oxime + Praziquantel (Interceptor Plus) 118 reports · 0.4% of its reports
Skin disorders after Milbemycin Oxime (Interceptor) 35 reports · 0.1% of its reports
Skin disorders after Selamectin (Revolution) 42 reports · 0.1% of its reports
Skin disorders after Ivermectin (Heartgard) 47 reports · 0.4% of its reports

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