Gall bladder & bile duct disorder after Milbemycin Oxime + Spinosad (Trifexis) in dogs

84 reports to the FDA describe gall bladder & bile duct disorder in dogs given Milbemycin Oxime + Spinosad. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported less often than average with this medicine.

84Reports

89%Marked serious

19%Recovered

35%Died or euthanised

30 daysTypical onset

How soon it started

Same day

14 28%

1–2 days

5 10%

3–7 days

1 2.0%

1–4 weeks

7 14%

Over a month

23 46%

How the animals did

Recovered

5 6.0%

Recovered with lasting effects

11 13%

Still unwell when reported

13 15%

Died

12 14%

Euthanised

17 20%

Not known

26 31%

Problems reported at the same time

62 74%

52 62%

39 46%

34 40%

Abnormal ultrasound finding

30 36%

Death

29 35%

Kidney problems

27 32%

Diarrhea

21 25%

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 gall bladder & bile duct disorder in dogs?: 84 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 30 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).

Gall bladder & bile duct disorder with similar medicines

Gall bladder & bile duct disorder after Ivermectin + Pyrantel (Heartgard Plus) 35 reports · 0.0% of its reports
Gall bladder & bile duct disorder after Moxidectin (ProHeart 6) 50 reports · 0.1% of its reports
Gall bladder & bile duct disorder after Milbemycin Oxime + Praziquantel (Interceptor Plus) 22 reports · 0.1% of its reports

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with gall bladder & bile duct disorder