Systemic disorder after Milbemycin Oxime + Spinosad (Trifexis) in dogs

404 reports to the FDA describe systemic disorder in dogs given Milbemycin Oxime + Spinosad. That is 0.3% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

404Reports

56%Marked serious

44%Recovered

21%Died or euthanised

Same dayTypical onset

How soon it started

Same day

147 50%

1–2 days

15 5.1%

3–7 days

8 2.7%

1–4 weeks

27 9.2%

Over a month

96 33%

How the animals did

Recovered

128 32%

Recovered with lasting effects

49 12%

Still unwell when reported

47 12%

Died

47 12%

Euthanised

39 9.7%

Not known

94 23%

Problems reported at the same time

161 40%

131 32%

118 29%

84 21%

77 19%

61 15%

58 14%

55 14%

Age of the animals

Under 1 year

1–3 years

105

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 systemic disorder in dogs?: 404 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).

Systemic disorder with similar medicines

Systemic disorder after Ivermectin + Pyrantel (Heartgard Plus) 136 reports · 0.1% of its reports
Systemic disorder after Moxidectin (ProHeart 6) 123 reports · 0.2% of its reports
Systemic disorder after Milbemycin Oxime + Praziquantel (Interceptor Plus) 21 reports · 0.1% of its reports
Systemic disorder after Milbemycin Oxime (Interceptor) 26 reports · 0.1% of its reports
Systemic disorder after Selamectin (Revolution) 76 reports · 0.3% of its reports
Systemic disorder after Ivermectin (Heartgard) 32 reports · 0.3% of its reports

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