Scale after Selamectin (Revolution) in dogs

The FDA has received 59 reports of scale in dogs after Selamectin. That is 0.2% of all reports for this medicine, compared with 0.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

59Reports

3.4%Marked serious

0.0%Recovered

0.0%Died or euthanised

–Typical onset

How the animals did

Still unwell when reported

1 1.7%

Not known

58 98%

Problems reported at the same time

Hair loss

20 34%

Itching

19 32%

Seborrhoea

16 27%

Application site reaction

14 24%

Dry skin

11 19%

Skin rash or irritation

9 15%

Crust

8 14%

Hair modification

5 8.5%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 scale in dogs?: 59 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.
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).

Scale with similar medicines

Scale after Ivermectin + Pyrantel (Heartgard Plus) 25 reports · 0.0% of its reports
Scale after Milbemycin Oxime + Spinosad (Trifexis) 23 reports · 0.0% of its reports

All reported side effects of Selamectin in dogs · Medicines most reported with scale