Proprioception deficit after Milbemycin Oxime + Spinosad (Trifexis) in dogs

124 reports to the FDA describe proprioception deficit in dogs given Milbemycin Oxime + Spinosad. That is 0.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported less often than average with this medicine.

124Reports

86%Marked serious

29%Recovered

25%Died or euthanised

14 daysTypical onset

How soon it started

Same day

26 30%

1–2 days

9 10%

3–7 days

5 5.7%

1–4 weeks

7 8.0%

Over a month

40 46%

How the animals did

Recovered

18 15%

Recovered with lasting effects

18 15%

Still unwell when reported

36 29%

Died

9 7.3%

Euthanised

22 18%

Not known

21 17%

Problems reported at the same time

59 48%

48 39%

34 27%

33 27%

33 27%

32 26%

29 23%

29 23%

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 proprioception deficit in dogs?: 124 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 14 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).

Proprioception deficit with similar medicines

Proprioception deficit after Ivermectin + Pyrantel (Heartgard Plus) 42 reports · 0.0% of its reports
Proprioception deficit after Moxidectin (ProHeart 6) 66 reports · 0.1% of its reports
Proprioception deficit after Milbemycin Oxime + Praziquantel (Interceptor Plus) 24 reports · 0.1% of its reports
Proprioception deficit after Ivermectin (Heartgard) 28 reports · 0.2% of its reports

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with proprioception deficit