Staggering after Milbemycin Oxime + Spinosad (Trifexis) in dogs

150 reports to the FDA describe staggering 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.

150Reports

40%Marked serious

61%Recovered

10%Died or euthanised

2 daysTypical onset

How soon it started

Same day

47 40%

1–2 days

13 11%

3–7 days

4 3.4%

1–4 weeks

12 10%

Over a month

41 35%

How the animals did

Recovered

79 53%

Recovered with lasting effects

13 8.7%

Still unwell when reported

13 8.7%

Died

10 6.7%

Euthanised

5 3.3%

Not known

30 20%

Problems reported at the same time

58 39%

56 37%

35 23%

29 19%

20 13%

19 13%

18 12%

16 11%

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 staggering in dogs?: 150 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 2 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).

Staggering with similar medicines

Staggering after Ivermectin + Pyrantel (Heartgard Plus) 275 reports · 0.2% of its reports
Staggering after Moxidectin (ProHeart 6) 83 reports · 0.2% of its reports
Staggering after Milbemycin Oxime + Praziquantel (Interceptor Plus) 25 reports · 0.1% of its reports
Staggering after Milbemycin Oxime (Interceptor) 38 reports · 0.1% of its reports
Staggering after Selamectin (Revolution) 35 reports · 0.1% of its reports
Staggering after Ivermectin (Heartgard) 88 reports · 0.7% of its reports
Staggering after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 25 reports · 0.3% of its reports

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