Wobbliness (ataxia) after Spinosad (Comfortis) in cats

186 reports to the FDA describe wobbliness (ataxia) in cats given Spinosad. That is 1.6% 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.

186Reports
30%Marked serious
51%Recovered
7.5%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
72 45%
1–2 days
41 26%
3–7 days
7 4.4%
1–4 weeks
10 6.3%
Over a month
29 18%

How the animals did

Recovered
74 40%
Recovered with lasting effects
21 11%
Still unwell when reported
28 15%
Died
9 4.8%
Euthanised
5 2.7%
Not known
49 26%

Problems reported at the same time

Age of the animals

Under 1 year
27
1–3 years
44
4–7 years
42
8–11 years
25
12+ years
37

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 wobbliness (ataxia) in cats?
186 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 1 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).

Wobbliness (ataxia) with similar medicines

All reported side effects of Spinosad in cats · Medicines most reported with wobbliness (ataxia)