Cataract after Spinosad (Comfortis) in dogs

The FDA has received 52 reports of cataract in dogs after Spinosad. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

52Reports

67%Marked serious

42%Recovered

5.8%Died or euthanised

31 daysTypical onset

How soon it started

Same day

3 14%

1–2 days

3 14%

3–7 days

0 0.0%

1–4 weeks

4 19%

Over a month

11 52%

How the animals did

Recovered with lasting effects

22 42%

Still unwell when reported

9 17%

Died

2 3.8%

Euthanised

1 1.9%

Not known

18 35%

Problems reported at the same time

Eye or vision problems

25 48%

Vomiting

10 19%

Behaviour change

9 17%

Lethargy

8 15%

Abnormal menace reflex test

8 15%

Eye disorder (for photophobia see 'neurological')

7 13%

Uveitis

6 12%

Arthritis

6 12%

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 cataract in dogs?: 52 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 31 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).

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