Pancreatitis after Milbemycin Oxime + Spinosad (Trifexis) in dogs

358 reports to the FDA describe pancreatitis in dogs given Milbemycin Oxime + Spinosad. That is 0.3% of all reports for this medicine, compared with 0.4% across reports for all dog medicines.

358Reports

80%Marked serious

39%Recovered

16%Died or euthanised

14 daysTypical onset

How soon it started

Same day

57 28%

1–2 days

21 10%

3–7 days

10 4.9%

1–4 weeks

28 14%

Over a month

87 43%

How the animals did

Recovered

100 28%

Recovered with lasting effects

38 11%

Still unwell when reported

73 20%

Died

26 7.3%

Euthanised

30 8.4%

Not known

91 25%

Problems reported at the same time

205 57%

115 32%

105 29%

105 29%

95 27%

55 15%

49 14%

47 13%

Age of the animals

Under 1 year

1–3 years

4–7 years

107

8–11 years

104

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 pancreatitis in dogs?: 358 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 14 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).

Pancreatitis with similar medicines

Pancreatitis after Ivermectin + Pyrantel (Heartgard Plus) 192 reports · 0.1% of its reports
Pancreatitis after Moxidectin (ProHeart 6) 139 reports · 0.3% of its reports
Pancreatitis after Milbemycin Oxime + Praziquantel (Interceptor Plus) 74 reports · 0.2% of its reports
Pancreatitis after Milbemycin Oxime (Interceptor) 59 reports · 0.2% of its reports
Pancreatitis after Selamectin (Revolution) 43 reports · 0.1% of its reports
Pancreatitis after Ivermectin (Heartgard) 35 reports · 0.3% of its reports

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