Hyperglycaemia after Milbemycin Oxime + Spinosad (Trifexis) in dogs

The FDA has received 356 reports of hyperglycaemia in dogs after Milbemycin Oxime + Spinosad. That is 0.3% of all reports for this medicine, compared with 0.5% across reports for all dog medicines, so it is reported less often than average with this medicine.

356Reports

78%Marked serious

36%Recovered

22%Died or euthanised

6 daysTypical onset

How soon it started

Same day

80 32%

1–2 days

33 13%

3–7 days

18 7.1%

1–4 weeks

26 10%

Over a month

96 38%

How the animals did

Recovered

60 17%

Recovered with lasting effects

67 19%

Still unwell when reported

73 21%

Died

39 11%

Euthanised

40 11%

Not known

77 22%

Problems reported at the same time

171 48%

161 45%

153 43%

114 32%

84 24%

83 23%

79 22%

77 22%

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 hyperglycaemia in dogs?: 356 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).

Hyperglycaemia with similar medicines

Hyperglycaemia after Ivermectin + Pyrantel (Heartgard Plus) 225 reports · 0.2% of its reports
Hyperglycaemia after Moxidectin (ProHeart 6) 208 reports · 0.4% of its reports
Hyperglycaemia after Milbemycin Oxime + Praziquantel (Interceptor Plus) 77 reports · 0.2% of its reports
Hyperglycaemia after Milbemycin Oxime (Interceptor) 51 reports · 0.2% of its reports
Hyperglycaemia after Selamectin (Revolution) 58 reports · 0.2% of its reports
Hyperglycaemia after Ivermectin (Heartgard) 77 reports · 0.6% of its reports
Hyperglycaemia after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 23 reports · 0.3% of its reports

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