Crust after Spinosad (Comfortis) in dogs

56 reports to the FDA describe crust in dogs given Spinosad. That is 0.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported less often than average with this medicine.

56Reports

38%Marked serious

14%Recovered

11%Died or euthanised

29 daysTypical onset

How soon it started

Same day

3 13%

1–2 days

3 13%

3–7 days

1 4.2%

1–4 weeks

6 25%

Over a month

11 46%

How the animals did

Recovered

1 1.8%

Recovered with lasting effects

7 13%

Still unwell when reported

13 23%

Died

3 5.4%

Euthanised

3 5.4%

Not known

29 52%

Problems reported at the same time

Hair loss

21 38%

Itching

17 30%

Skin rash or irritation

16 29%

12 21%

11 20%

10 18%

9 16%

9 16%

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 crust in dogs?: 56 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 29 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).

Crust with similar medicines

Crust after Lufenuron + Milbemycin Oxime (Sentinel) 34 reports · 0.1% of its reports
Crust after Imidacloprid + Moxidectin (Advantage Multi) 24 reports · 0.2% of its reports

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