Accidental exposure after Milbemycin Oxime + Spinosad (Trifexis) in dogs

1,509 reports to the FDA describe accidental exposure in dogs given Milbemycin Oxime + Spinosad. That is 1.2% of all reports for this medicine, compared with 1.5% across reports for all dog medicines.

1,509Reports

19%Marked serious

50%Recovered

0.9%Died or euthanised

Same dayTypical onset

How soon it started

Same day

452 58%

1–2 days

160 20%

3–7 days

14 1.8%

1–4 weeks

21 2.7%

Over a month

136 17%

How the animals did

Recovered

685 45%

Recovered with lasting effects

69 4.6%

Still unwell when reported

224 15%

Died

7 0.5%

Euthanised

6 0.4%

Not known

518 34%

Problems reported at the same time

842 56%

841 56%

719 48%

317 21%

240 16%

162 11%

85 5.6%

70 4.6%

Age of the animals

Under 1 year

360

1–3 years

492

4–7 years

291

8–11 years

181

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 accidental exposure in dogs?: 1,509 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).

Accidental exposure with similar medicines

Accidental exposure after Ivermectin + Pyrantel (Heartgard Plus) 583 reports · 0.4% of its reports
Accidental exposure after Moxidectin (ProHeart 6) 221 reports · 0.4% of its reports
Accidental exposure after Milbemycin Oxime + Praziquantel (Interceptor Plus) 86 reports · 0.3% of its reports
Accidental exposure after Milbemycin Oxime (Interceptor) 411 reports · 1.4% of its reports
Accidental exposure after Selamectin (Revolution) 311 reports · 1.1% of its reports
Accidental exposure after Ivermectin (Heartgard) 434 reports · 3.6% of its reports
Accidental exposure after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 118 reports · 1.4% of its reports
Accidental exposure after Ivermectin + Praziquantel 51 reports · 25% of its reports
Accidental exposure after Eprinomectin 57 reports · 54% of its reports
Accidental exposure after Moxidectin + Praziquantel 22 reports · 29% of its reports

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