Wobbliness (ataxia) after Sarolaner + Selamectin (Revolution Plus) in cats

241 reports to the FDA describe wobbliness (ataxia) in cats given Sarolaner + Selamectin. That is 2.9% 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.

241Reports
59%Marked serious
21%Recovered
7.1%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
105 45%
1–2 days
72 31%
3–7 days
29 12%
1–4 weeks
19 8.2%
Over a month
8 3.4%

How the animals did

Recovered
50 21%
Still unwell when reported
141 59%
Died
7 2.9%
Euthanised
10 4.1%
Not known
33 14%

Problems reported at the same time

Age of the animals

Under 1 year
40
1–3 years
47
4–7 years
47
8–11 years
37
12+ years
61

About this medicine

Sarolaner kills fleas, ticks and some mites; monthly. Selamectin prevents heartworm and treats fleas, ear mites and some worms (spot-on).

Products with this combination include Revolution Plus. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

In 2018 the FDA alerted owners and vets that isoxazoline products have been associated with neurologic reactions such as muscle tremors, wobbliness (ataxia) and seizures, including in animals with no history of them.

Questions owners ask

Can Sarolaner + Selamectin cause wobbliness (ataxia) in cats?
241 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 Sarolaner + Selamectin in cats · Medicines most reported with wobbliness (ataxia)