Abnormal menace reflex test after Milbemycin Oxime + Spinosad (Trifexis) in dogs

99 reports to the FDA describe abnormal menace reflex test 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.

99Reports

96%Marked serious

58%Recovered

14%Died or euthanised

33 daysTypical onset

How soon it started

Same day

16 20%

1–2 days

8 10%

3–7 days

4 5.0%

1–4 weeks

10 13%

Over a month

42 53%

How the animals did

Recovered

31 31%

Recovered with lasting effects

26 26%

Still unwell when reported

12 12%

Died

6 6.1%

Euthanised

8 8.1%

Not known

16 16%

Problems reported at the same time

Eye or vision problems

52 53%

41 41%

38 38%

31 31%

31 31%

Abnormal pupil light reflex

29 29%

Lethargy

26 26%

Vomiting

25 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 abnormal menace reflex test in dogs?: 99 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 33 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).

Abnormal menace reflex test with similar medicines

Abnormal menace reflex test after Ivermectin + Pyrantel (Heartgard Plus) 37 reports · 0.0% of its reports
Abnormal menace reflex test after Moxidectin (ProHeart 6) 30 reports · 0.1% of its reports
Abnormal menace reflex test after Ivermectin (Heartgard) 63 reports · 0.5% of its reports

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with abnormal menace reflex test