Breathing problems after Spinosad (Comfortis) in cats

261 reports to the FDA describe breathing problems in cats given Spinosad. That is 2.3% of all reports for this medicine, compared with 4.7% across reports for all cat medicines, so it is reported less often than average with this medicine.

261Reports
55%Marked serious
48%Recovered
15%Died or euthanised
Same dayTypical onset
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How soon it started

Same day
183 75%
1–2 days
21 8.6%
3–7 days
11 4.5%
1–4 weeks
7 2.9%
Over a month
23 9.4%

How the animals did

Recovered
104 40%
Recovered with lasting effects
20 7.7%
Still unwell when reported
31 12%
Died
30 11%
Euthanised
10 3.8%
Not known
66 25%

Problems reported at the same time

Age of the animals

Under 1 year
26
1–3 years
78
4–7 years
71
8–11 years
36
12+ years
38

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 breathing problems in cats?
261 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 the same day 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).

Breathing problems with similar medicines

All reported side effects of Spinosad in cats · Medicines most reported with breathing problems