Digestive tract disorder after Milbemycin Oxime + Spinosad (Trifexis) in dogs

487 reports to the FDA describe digestive tract disorder in dogs given Milbemycin Oxime + Spinosad. That is 0.4% of all reports for this medicine, compared with 2.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

487Reports

49%Marked serious

42%Recovered

15%Died or euthanised

5 daysTypical onset

How soon it started

Same day

124 37%

1–2 days

39 12%

3–7 days

8 2.4%

1–4 weeks

28 8.3%

Over a month

138 41%

How the animals did

Recovered

152 31%

Recovered with lasting effects

54 11%

Still unwell when reported

74 15%

Died

48 9.9%

Euthanised

26 5.3%

Not known

133 27%

Problems reported at the same time

251 52%

162 33%

138 28%

113 23%

70 14%

66 14%

Abnormal radiograph finding

66 14%

Weight loss

59 12%

Age of the animals

Under 1 year

1–3 years

156

4–7 years

114

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 digestive tract disorder in dogs?: 487 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).

Digestive tract disorder with similar medicines

Digestive tract disorder after Ivermectin + Pyrantel (Heartgard Plus) 16,532 reports · 11% of its reports
Digestive tract disorder after Moxidectin (ProHeart 6) 88 reports · 0.2% of its reports
Digestive tract disorder after Milbemycin Oxime + Praziquantel (Interceptor Plus) 123 reports · 0.4% of its reports
Digestive tract disorder after Milbemycin Oxime (Interceptor) 178 reports · 0.6% of its reports
Digestive tract disorder after Selamectin (Revolution) 75 reports · 0.3% of its reports
Digestive tract disorder after Ivermectin (Heartgard) 63 reports · 0.5% of its reports
Digestive tract disorder after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 61 reports · 0.7% of its reports

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with digestive tract disorder