Gagging after Milbemycin Oxime + Spinosad (Trifexis) in dogs

296 reports to the FDA describe gagging in dogs given Milbemycin Oxime + Spinosad. That is 0.2% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

296Reports

25%Marked serious

62%Recovered

5.7%Died or euthanised

Same dayTypical onset

How soon it started

Same day

133 57%

1–2 days

20 8.6%

3–7 days

6 2.6%

1–4 weeks

14 6.0%

Over a month

60 26%

How the animals did

Recovered

157 53%

Recovered with lasting effects

27 9.1%

Still unwell when reported

32 11%

Died

10 3.4%

Euthanised

7 2.4%

Not known

63 21%

Problems reported at the same time

151 51%

102 34%

54 18%

48 16%

37 13%

35 12%

32 11%

31 10%

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 gagging in dogs?: 296 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 the same 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).

Gagging with similar medicines

Gagging after Ivermectin + Pyrantel (Heartgard Plus) 194 reports · 0.1% of its reports
Gagging after Moxidectin (ProHeart 6) 78 reports · 0.2% of its reports
Gagging after Milbemycin Oxime + Praziquantel (Interceptor Plus) 71 reports · 0.2% of its reports
Gagging after Milbemycin Oxime (Interceptor) 40 reports · 0.1% of its reports
Gagging after Selamectin (Revolution) 56 reports · 0.2% of its reports
Gagging after Ivermectin (Heartgard) 20 reports · 0.2% of its reports

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