Drooling after Ivermectin (Heartgard) in dogs

The FDA has received 494 reports of drooling in dogs after Ivermectin. That is 4.1% of all reports for this medicine, compared with 1.4% across reports for all dog medicines, so it is reported unusually often with this medicine.

494Reports

27%Marked serious

35%Recovered

12%Died or euthanised

33 daysTypical onset

How soon it started

Same day

30 13%

1–2 days

22 9.6%

3–7 days

13 5.7%

1–4 weeks

44 19%

Over a month

120 52%

How the animals did

Recovered

148 30%

Recovered with lasting effects

23 4.7%

Still unwell when reported

41 8.3%

Died

50 10%

Euthanised

9 1.8%

Not known

223 45%

Problems reported at the same time

Wobbliness (ataxia)

228 46%

Tremors

177 36%

Eye or vision problems

140 28%

130 26%

114 23%

77 16%

58 12%

51 10%

Age of the animals

Under 1 year

118

1–3 years

178

4–7 years

8–11 years

12+ years

About this medicine

Ivermectin prevents heartworm disease (monthly).

Products with this ingredient include Heartgard. 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 cause drooling in dogs?: 494 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).

Drooling with similar medicines

Drooling after Ivermectin + Pyrantel (Heartgard Plus) 1,096 reports · 0.7% of its reports
Drooling after Milbemycin Oxime + Spinosad (Trifexis) 1,577 reports · 1.2% of its reports
Drooling after Moxidectin (ProHeart 6) 730 reports · 1.4% of its reports
Drooling after Milbemycin Oxime + Praziquantel (Interceptor Plus) 420 reports · 1.3% of its reports
Drooling after Milbemycin Oxime (Interceptor) 354 reports · 1.2% of its reports
Drooling after Selamectin (Revolution) 469 reports · 1.6% of its reports
Drooling after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 166 reports · 1.9% of its reports
Drooling after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 21 reports · 1.8% of its reports

All reported side effects of Ivermectin in dogs · Medicines most reported with drooling