Itching after Selamectin (Revolution) in cats

The FDA has received 2,363 reports of itching in cats after Selamectin. That is 11% of all reports for this medicine, compared with 8.9% across reports for all cat medicines.

2,363Reports

7.5%Marked serious

8.1%Recovered

2.1%Died or euthanised

1 daysTypical onset

How soon it started

Same day

447 38%

1–2 days

349 30%

3–7 days

174 15%

1–4 weeks

111 9.6%

Over a month

81 7.0%

How the animals did

Recovered

187 7.9%

Recovered with lasting effects

4 0.2%

Still unwell when reported

566 24%

Died

43 1.8%

Euthanised

7 0.3%

Not known

1,556 66%

Problems reported at the same time

Hair loss

1,347 57%

Application site reaction

739 31%

Skin redness

266 11%

Skin rash or irritation

205 8.7%

172 7.3%

143 6.1%

142 6.0%

128 5.4%

Age of the animals

Under 1 year

365

1–3 years

732

4–7 years

540

8–11 years

334

12+ years

208

About this medicine

Selamectin prevents heartworm and treats fleas, ear mites and some worms (spot-on).

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

Some herding breeds (for example Collies) carry the MDR1 gene variant and can be more sensitive to this drug class at high doses.

Questions owners ask

Can Selamectin cause itching in cats?: 2,363 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).

Itching with similar medicines

Itching after Eprinomectin + Esafoxolaner + Praziquantel (NexGard Combo) 334 reports · 10% of its reports
Itching after Ivermectin (Heartgard) 48 reports · 5.0% of its reports
Itching after Eprinomectin + Praziquantel 41 reports · 7.0% of its reports
Itching after Milbemycin Oxime (Interceptor) 21 reports · 5.2% of its reports

All reported side effects of Selamectin in cats · Medicines most reported with itching