Hair loss after Selamectin (Revolution) in dogs

The FDA has received 1,036 reports of hair loss in dogs after Selamectin. That is 3.5% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

1,036Reports

3.5%Marked serious

3.3%Recovered

0.8%Died or euthanised

2 daysTypical onset

How soon it started

Same day

98 36%

1–2 days

67 25%

3–7 days

32 12%

1–4 weeks

40 15%

Over a month

35 13%

How the animals did

Recovered

33 3.2%

Recovered with lasting effects

1 0.1%

Still unwell when reported

127 12%

Died

7 0.7%

Euthanised

1 0.1%

Not known

867 84%

Problems reported at the same time

Application site reaction

277 27%

Itching

267 26%

Skin rash or irritation

113 11%

98 9.5%

52 5.0%

40 3.9%

40 3.9%

38 3.7%

Age of the animals

Under 1 year

196

1–3 years

352

4–7 years

256

8–11 years

129

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 hair loss in dogs?: 1,036 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).

Hair loss with similar medicines

Hair loss after Ivermectin + Pyrantel (Heartgard Plus) 539 reports · 0.4% of its reports
Hair loss after Milbemycin Oxime + Spinosad (Trifexis) 1,029 reports · 0.8% of its reports
Hair loss after Moxidectin (ProHeart 6) 325 reports · 0.6% of its reports
Hair loss after Milbemycin Oxime + Praziquantel (Interceptor Plus) 158 reports · 0.5% of its reports
Hair loss after Milbemycin Oxime (Interceptor) 132 reports · 0.4% of its reports
Hair loss after Ivermectin (Heartgard) 104 reports · 0.9% of its reports
Hair loss after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 20 reports · 0.2% of its reports

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