Blood problems after Sarolaner + Selamectin (Revolution Plus) in cats

66 reports to the FDA describe blood problems in cats given Sarolaner + Selamectin. That is 0.8% of all reports for this medicine, compared with 1.9% across reports for all cat medicines, so it is reported less often than average with this medicine.

66Reports
80%Marked serious
9.1%Recovered
21%Died or euthanised
2 daysTypical onset
SponsoredWorried about your pet? Ask a veterinarian online, 24/7

How soon it started

Same day
18 30%
1–2 days
19 31%
3–7 days
7 11%
1–4 weeks
10 16%
Over a month
7 11%

How the animals did

Recovered
6 9.1%
Still unwell when reported
41 62%
Died
5 7.6%
Euthanised
9 14%
Not known
5 7.6%

Problems reported at the same time

Age of the animals

Under 1 year
10
1–3 years
18
4–7 years
14
8–11 years
12
12+ years
10

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 blood problems in cats?
66 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 2 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).

Blood problems with similar medicines

All reported side effects of Sarolaner + Selamectin in cats · Medicines most reported with blood problems