Walking difficulty after Spinosad (Comfortis) in dogs

The FDA has received 148 reports of walking difficulty in dogs after Spinosad. That is 0.3% of all reports for this medicine, compared with 0.4% across reports for all dog medicines, so it is reported less often than average with this medicine.

148Reports

63%Marked serious

47%Recovered

22%Died or euthanised

2 daysTypical onset

How soon it started

Same day

38 38%

1–2 days

16 16%

3–7 days

7 7.0%

1–4 weeks

9 9.0%

Over a month

30 30%

How the animals did

Recovered

43 29%

Recovered with lasting effects

27 18%

Still unwell when reported

15 10%

Died

14 9.5%

Euthanised

19 13%

Not known

30 20%

Problems reported at the same time

76 51%

56 38%

52 35%

51 34%

33 22%

32 22%

31 21%

26 18%

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 walking difficulty in dogs?: 148 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 2 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).

Walking difficulty with similar medicines

Walking difficulty after Lufenuron + Milbemycin Oxime (Sentinel) 53 reports · 0.2% of its reports
Walking difficulty after Imidacloprid + Moxidectin (Advantage Multi) 36 reports · 0.3% of its reports
Walking difficulty after Nitenpyram (Capstar) 53 reports · 0.5% of its reports
Walking difficulty after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 34 reports · 0.3% of its reports
Walking difficulty after Fipronil + S-methoprene (Frontline Plus) 25 reports · 0.8% of its reports
Walking difficulty after Imidacloprid 29 reports · 1.5% of its reports

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