Otitis externa after Spinosad (Comfortis) in dogs

The FDA has received 61 reports of otitis externa in dogs after Spinosad. That is 0.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

61Reports

28%Marked serious

11%Recovered

3.3%Died or euthanised

114 daysTypical onset

How soon it started

Same day

1 5.6%

1–2 days

1 5.6%

3–7 days

0 0.0%

1–4 weeks

2 11%

Over a month

14 78%

How the animals did

Recovered

4 6.6%

Recovered with lasting effects

3 4.9%

Still unwell when reported

12 20%

Died

2 3.3%

Not known

40 66%

Problems reported at the same time

14 23%

12 20%

12 20%

12 20%

Skin rash or irritation

10 16%

Tremors

8 13%

Pyoderma

6 9.8%

Head tilt - ear disorder

6 9.8%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Spinosad kills fleas; monthly chewable.

Products with this ingredient include Comfortis. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Spinosad cause otitis externa in dogs?: 61 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 114 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).

Otitis externa with similar medicines

Otitis externa after Lufenuron + Milbemycin Oxime (Sentinel) 31 reports · 0.1% of its reports
Otitis externa after Imidacloprid + Moxidectin (Advantage Multi) 24 reports · 0.2% of its reports

All reported side effects of Spinosad in dogs · Medicines most reported with otitis externa