Inappropriate urination after Spinosad (Comfortis) in dogs

The FDA has received 140 reports of inappropriate urination in dogs after Spinosad. That is 0.2% of all reports for this medicine, compared with 0.5% across reports for all dog medicines, so it is reported less often than average with this medicine.

140Reports

46%Marked serious

54%Recovered

12%Died or euthanised

3 daysTypical onset

How soon it started

Same day

33 34%

1–2 days

13 14%

3–7 days

5 5.2%

1–4 weeks

9 9.4%

Over a month

36 38%

How the animals did

Recovered

47 34%

Recovered with lasting effects

28 20%

Still unwell when reported

19 14%

Died

6 4.3%

Euthanised

11 7.9%

Not known

29 21%

Problems reported at the same time

51 36%

42 30%

35 25%

28 20%

Inappropriate defecation

23 16%

Behaviour change

23 16%

Breathing problems

22 16%

Liver problems

19 14%

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 inappropriate urination in dogs?: 140 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 3 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).

Inappropriate urination with similar medicines

Inappropriate urination after Lufenuron + Milbemycin Oxime (Sentinel) 59 reports · 0.2% of its reports
Inappropriate urination after Imidacloprid + Moxidectin (Advantage Multi) 76 reports · 0.6% of its reports
Inappropriate urination after Nitenpyram (Capstar) 28 reports · 0.3% of its reports
Inappropriate urination after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 27 reports · 0.3% of its reports
Inappropriate urination after Fipronil + S-methoprene (Frontline Plus) 24 reports · 0.8% of its reports

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