Pacing after Milbemycin Oxime + Spinosad (Trifexis) in dogs

139 reports to the FDA describe pacing in dogs given Milbemycin Oxime + Spinosad. That is 0.1% of all reports for this medicine, compared with 0.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

139Reports

37%Marked serious

50%Recovered

8.6%Died or euthanised

1 daysTypical onset

How soon it started

Same day

43 47%

1–2 days

6 6.6%

3–7 days

1 1.1%

1–4 weeks

5 5.5%

Over a month

36 40%

How the animals did

Recovered

56 40%

Recovered with lasting effects

13 9.4%

Still unwell when reported

29 21%

Died

5 3.6%

Euthanised

7 5.0%

Not known

29 21%

Problems reported at the same time

44 32%

44 32%

43 31%

39 28%

37 27%

31 22%

Restlessness or agitation

25 18%

Vocalising

23 17%

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 pacing in dogs?: 139 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 1 day 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).

Pacing with similar medicines

Pacing after Ivermectin + Pyrantel (Heartgard Plus) 205 reports · 0.1% of its reports
Pacing after Moxidectin (ProHeart 6) 119 reports · 0.2% of its reports
Pacing after Milbemycin Oxime + Praziquantel (Interceptor Plus) 54 reports · 0.2% of its reports
Pacing after Milbemycin Oxime (Interceptor) 37 reports · 0.1% of its reports
Pacing after Selamectin (Revolution) 112 reports · 0.4% of its reports
Pacing after Ivermectin (Heartgard) 27 reports · 0.2% of its reports

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