Closed eyelid after Milbemycin Oxime + Spinosad (Trifexis) in dogs

141 reports to the FDA describe closed eyelid in dogs given Milbemycin Oxime + Spinosad. That is 0.1% of all reports for this medicine, compared with 0.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

141Reports
28%Marked serious
65%Recovered
2.1%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
47 49%
1–2 days
10 11%
3–7 days
1 1.1%
1–4 weeks
5 5.3%
Over a month
32 34%

How the animals did

Recovered
77 55%
Recovered with lasting effects
14 9.9%
Still unwell when reported
18 13%
Died
3 2.1%
Not known
29 21%

Problems reported at the same time

Age of the animals

Under 1 year
40
1–3 years
64
4–7 years
30
8–11 years
3
12+ years
0

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 closed eyelid in dogs?
141 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 1 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).

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