Behaviour change after Sarolaner + Selamectin (Revolution Plus) in cats

317 reports to the FDA describe behaviour change in cats given Sarolaner + Selamectin. That is 3.9% of all reports for this medicine, compared with 5.4% across reports for all cat medicines.

317Reports
31%Marked serious
18%Recovered
4.1%Died or euthanised
Same dayTypical onset
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How soon it started

Same day
184 59%
1–2 days
74 24%
3–7 days
16 5.1%
1–4 weeks
21 6.7%
Over a month
17 5.4%

How the animals did

Recovered
58 18%
Still unwell when reported
120 38%
Died
10 3.2%
Euthanised
3 0.9%
Not known
126 40%

Problems reported at the same time

Age of the animals

Under 1 year
35
1–3 years
97
4–7 years
82
8–11 years
39
12+ years
31

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 behaviour change in cats?
317 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).

Behaviour change with similar medicines

All reported side effects of Sarolaner + Selamectin in cats · Medicines most reported with behaviour change