Skin rash or irritation after Ivermectin + Pyrantel (Heartgard Plus) in dogs

The FDA has received 664 reports of skin rash or irritation in dogs after Ivermectin + Pyrantel. That is 0.4% of all reports for this medicine, compared with 1.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

664Reports

49%Marked serious

16%Recovered

3.9%Died or euthanised

20 daysTypical onset

How soon it started

Same day

64 19%

1–2 days

44 13%

3–7 days

36 11%

1–4 weeks

51 15%

Over a month

141 42%

How the animals did

Recovered

92 14%

Recovered with lasting effects

16 2.4%

Still unwell when reported

104 16%

Died

17 2.6%

Euthanised

9 1.4%

Not known

426 64%

Problems reported at the same time

256 39%

87 13%

85 13%

75 11%

58 8.7%

57 8.6%

52 7.8%

50 7.5%

Age of the animals

Under 1 year

1–3 years

212

4–7 years

189

8–11 years

121

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 rash or irritation in dogs?: 664 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 20 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 rash or irritation with similar medicines

Skin rash or irritation after Milbemycin Oxime + Spinosad (Trifexis) 1,342 reports · 1.0% of its reports
Skin rash or irritation after Moxidectin (ProHeart 6) 446 reports · 0.9% of its reports
Skin rash or irritation after Milbemycin Oxime + Praziquantel (Interceptor Plus) 234 reports · 0.7% of its reports
Skin rash or irritation after Milbemycin Oxime (Interceptor) 234 reports · 0.8% of its reports
Skin rash or irritation after Selamectin (Revolution) 728 reports · 2.5% of its reports
Skin rash or irritation after Ivermectin (Heartgard) 138 reports · 1.1% of its reports
Skin rash or irritation after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 20 reports · 0.2% of its reports

All reported side effects of Ivermectin + Pyrantel in dogs · Medicines most reported with skin rash or irritation