Dry nose after Milbemycin Oxime + Spinosad (Trifexis) in dogs

The FDA has received 59 reports of dry nose in dogs after Milbemycin Oxime + Spinosad. That is 0.0% of all reports for this medicine, compared with 0.0% across reports for all dog medicines.

59Reports

10%Marked serious

56%Recovered

1.7%Died or euthanised

Same dayTypical onset

How soon it started

Same day

26 55%

1–2 days

8 17%

3–7 days

1 2.1%

1–4 weeks

1 2.1%

Over a month

11 23%

How the animals did

Recovered

25 42%

Recovered with lasting effects

8 14%

Still unwell when reported

10 17%

Euthanised

1 1.7%

Not known

15 25%

Problems reported at the same time

41 69%

23 39%

20 34%

12 20%

9 15%

9 15%

6 10%

6 10%

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 dry nose in dogs?: 59 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).

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