Hypoglycaemia after Milbemycin Oxime + Spinosad (Trifexis) in dogs

147 reports to the FDA describe hypoglycaemia in dogs given Milbemycin Oxime + Spinosad. That is 0.1% of all reports for this medicine, compared with 0.4% across reports for all dog medicines, so it is reported less often than average with this medicine.

147Reports

85%Marked serious

31%Recovered

32%Died or euthanised

6 daysTypical onset

How soon it started

Same day

37 34%

1–2 days

14 13%

3–7 days

7 6.4%

1–4 weeks

11 10%

Over a month

41 37%

How the animals did

Recovered

24 16%

Recovered with lasting effects

21 14%

Still unwell when reported

28 19%

Died

27 18%

Euthanised

20 14%

Not known

27 18%

Problems reported at the same time

75 51%

71 48%

67 46%

65 44%

47 32%

40 27%

38 26%

34 23%

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 hypoglycaemia in dogs?: 147 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 6 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).

Hypoglycaemia with similar medicines

Hypoglycaemia after Ivermectin + Pyrantel (Heartgard Plus) 93 reports · 0.1% of its reports
Hypoglycaemia after Moxidectin (ProHeart 6) 139 reports · 0.3% of its reports
Hypoglycaemia after Milbemycin Oxime + Praziquantel (Interceptor Plus) 32 reports · 0.1% of its reports
Hypoglycaemia after Milbemycin Oxime (Interceptor) 52 reports · 0.2% of its reports
Hypoglycaemia after Selamectin (Revolution) 92 reports · 0.3% of its reports
Hypoglycaemia after Ivermectin (Heartgard) 28 reports · 0.2% of its reports

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