Dermal mass after Selamectin (Revolution) in dogs

33 reports to the FDA describe dermal mass in dogs given Selamectin. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

33Reports
18%Marked serious
6.1%Recovered
9.1%Died or euthanised
61 daysTypical onset
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How soon it started

Same day
1 10%
1–2 days
0 0.0%
3–7 days
0 0.0%
1–4 weeks
3 30%
Over a month
6 60%

How the animals did

Recovered
2 6.1%
Still unwell when reported
9 27%
Died
2 6.1%
Euthanised
1 3.0%
Not known
19 58%

Problems reported at the same time

Skin tumour
3 9.1%
Histiocytoma
3 9.1%
3 9.1%

Age of the animals

Under 1 year
2
1–3 years
4
4–7 years
11
8–11 years
11
12+ years
4

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 dermal mass in dogs?
33 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 61 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).

Dermal mass with similar medicines

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