Bone and joint disorder after Ivermectin (Heartgard) in dogs

The FDA has received 29 reports of bone and joint disorder in dogs after Ivermectin. That is 0.2% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

29Reports

62%Marked serious

6.9%Recovered

10%Died or euthanised

99 daysTypical onset

How soon it started

Same day

3 17%

1–2 days

3 17%

3–7 days

0 0.0%

1–4 weeks

1 5.6%

Over a month

11 61%

How the animals did

Recovered

2 6.9%

Still unwell when reported

10 34%

Euthanised

3 10%

Not known

14 48%

Problems reported at the same time

Lameness

6 21%

Vomiting

6 21%

Didn't prevent heartworm

6 21%

Liver problems

5 17%

Didn't work as expected

5 17%

Diarrhea

4 14%

Lethargy

4 14%

Joint pain

4 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 bone and joint disorder in dogs?: 29 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 99 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).

Bone and joint disorder with similar medicines

Bone and joint disorder after Ivermectin + Pyrantel (Heartgard Plus) 33 reports · 0.0% of its reports
Bone and joint disorder after Milbemycin Oxime + Spinosad (Trifexis) 189 reports · 0.1% of its reports
Bone and joint disorder after Moxidectin (ProHeart 6) 23 reports · 0.0% of its reports
Bone and joint disorder after Milbemycin Oxime + Praziquantel (Interceptor Plus) 58 reports · 0.2% of its reports
Bone and joint disorder after Milbemycin Oxime (Interceptor) 29 reports · 0.1% of its reports

All reported side effects of Ivermectin in dogs · Medicines most reported with bone and joint disorder