Bone and joint disorder after Milbemycin Oxime (Interceptor) in dogs

The FDA has received 29 reports of bone and joint disorder in dogs after Milbemycin Oxime. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

29Reports
59%Marked serious
10%Recovered
10%Died or euthanised
–Typical onset
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How the animals did

Recovered with lasting effects
3 10%
Still unwell when reported
13 45%
Died
3 10%
Not known
10 34%

Problems reported at the same time

Vomiting
8 28%
Lethargy
6 21%
Loss of appetite
6 21%
Diarrhea
5 17%
Lameness
3 10%
Digestive tract disorder
3 10%
Skin rash or irritation
3 10%
Musculoskeletal disorder
3 10%

Age of the animals

Under 1 year
3
1–3 years
4
4–7 years
8
8–11 years
11
12+ years
0

About this medicine

Milbemycin Oxime prevents heartworm and controls some intestinal worms (monthly).

Products with this ingredient include Interceptor. 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 Milbemycin Oxime 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.
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

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