Inappropriate defecation after Spinosad (Comfortis) in dogs

The FDA has received 63 reports of inappropriate defecation in dogs after 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.

63Reports
51%Marked serious
54%Recovered
14%Died or euthanised
26 daysTypical onset
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How soon it started

Same day
13 33%
1–2 days
5 13%
3–7 days
0 0.0%
1–4 weeks
4 10%
Over a month
18 45%

How the animals did

Recovered
25 40%
Recovered with lasting effects
9 14%
Still unwell when reported
7 11%
Died
3 4.8%
Euthanised
6 9.5%
Not known
13 21%

Problems reported at the same time

Age of the animals

Under 1 year
2
1–3 years
18
4–7 years
16
8–11 years
17
12+ years
7

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 defecation in dogs?
63 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 26 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 defecation with similar medicines

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