Hiding after Ivermectin (Heartgard) in dogs

The FDA has received 21 reports of hiding in dogs after Ivermectin. That is 0.2% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

21Reports

19%Marked serious

24%Recovered

0.0%Died or euthanised

96 daysTypical onset

How soon it started

Same day

0 0.0%

1–2 days

2 15%

3–7 days

1 7.7%

1–4 weeks

3 23%

Over a month

7 54%

How the animals did

Recovered

4 19%

Recovered with lasting effects

1 4.8%

Still unwell when reported

5 24%

Not known

11 52%

Problems reported at the same time

8 38%

7 33%

5 24%

4 19%

Eye or vision problems

3 14%

Accidental exposure

3 14%

Wobbliness (ataxia)

3 14%

Breathing problems

3 14%

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).

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 hiding in dogs?: 21 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 96 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).

Hiding with similar medicines

Hiding after Ivermectin + Pyrantel (Heartgard Plus) 177 reports · 0.1% of its reports
Hiding after Milbemycin Oxime + Spinosad (Trifexis) 198 reports · 0.2% of its reports
Hiding after Moxidectin (ProHeart 6) 119 reports · 0.2% of its reports
Hiding after Milbemycin Oxime + Praziquantel (Interceptor Plus) 65 reports · 0.2% of its reports
Hiding after Milbemycin Oxime (Interceptor) 45 reports · 0.2% of its reports
Hiding after Selamectin (Revolution) 91 reports · 0.3% of its reports
Hiding after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 21 reports · 0.2% of its reports

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