Balance problem after Milbemycin Oxime + Spinosad (Trifexis) in dogs

93 reports to the FDA describe balance problem in dogs given Milbemycin Oxime + Spinosad. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

93Reports

49%Marked serious

56%Recovered

5.4%Died or euthanised

5 daysTypical onset

How soon it started

Same day

25 36%

1–2 days

8 12%

3–7 days

4 5.8%

1–4 weeks

4 5.8%

Over a month

28 41%

How the animals did

Recovered

39 42%

Recovered with lasting effects

13 14%

Still unwell when reported

11 12%

Died

2 2.2%

Euthanised

3 3.2%

Not known

25 27%

Problems reported at the same time

39 42%

31 33%

23 25%

22 24%

21 23%

18 19%

17 18%

14 15%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Milbemycin Oxime prevents heartworm and controls some intestinal worms (monthly). Spinosad kills fleas; monthly chewable.

Products with this combination include Trifexis. 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 + Spinosad cause balance problem in dogs?: 93 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 5 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).

Balance problem with similar medicines

Balance problem after Ivermectin + Pyrantel (Heartgard Plus) 60 reports · 0.0% of its reports
Balance problem after Moxidectin (ProHeart 6) 23 reports · 0.0% of its reports
Balance problem after Milbemycin Oxime + Praziquantel (Interceptor Plus) 23 reports · 0.1% of its reports
Balance problem after Ivermectin (Heartgard) 34 reports · 0.3% of its reports

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with balance problem