Excessive urination after Spinosad (Comfortis) in dogs

The FDA has received 159 reports of excessive urination in dogs after Spinosad. That is 0.3% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

159Reports
25%Marked serious
19%Recovered
10%Died or euthanised
11 daysTypical onset
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How soon it started

Same day
15 29%
1–2 days
4 7.7%
3–7 days
6 12%
1–4 weeks
7 13%
Over a month
20 38%

How the animals did

Recovered
14 8.8%
Recovered with lasting effects
16 10%
Still unwell when reported
16 10%
Died
12 7.5%
Euthanised
4 2.5%
Not known
97 61%

Problems reported at the same time

Age of the animals

Under 1 year
4
1–3 years
31
4–7 years
44
8–11 years
54
12+ years
24

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 excessive urination in dogs?
159 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 11 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).

Excessive urination with similar medicines

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