Weight gain after Selamectin (Revolution) in dogs

47 reports to the FDA describe weight gain in dogs given Selamectin. That is 0.2% of all reports for this medicine, compared with 0.6% across reports for all dog medicines, so it is reported less often than average with this medicine.

47Reports

8.5%Marked serious

4.3%Recovered

2.1%Died or euthanised

63 daysTypical onset

How soon it started

Same day

3 21%

1–2 days

1 7.1%

3–7 days

1 7.1%

1–4 weeks

0 0.0%

Over a month

9 64%

How the animals did

Recovered

2 4.3%

Still unwell when reported

16 34%

Euthanised

1 2.1%

Not known

28 60%

Problems reported at the same time

Didn't prevent heartworm

20 43%

12 26%

7 15%

5 11%

4 8.5%

4 8.5%

4 8.5%

Didn't work as expected

4 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 weight gain in dogs?: 47 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 63 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).

Weight gain with similar medicines

Weight gain after Ivermectin + Pyrantel (Heartgard Plus) 596 reports · 0.4% of its reports
Weight gain after Milbemycin Oxime + Spinosad (Trifexis) 2,619 reports · 2.0% of its reports
Weight gain after Moxidectin (ProHeart 6) 93 reports · 0.2% of its reports
Weight gain after Milbemycin Oxime + Praziquantel (Interceptor Plus) 575 reports · 1.8% of its reports
Weight gain after Milbemycin Oxime (Interceptor) 145 reports · 0.5% of its reports
Weight gain after Ivermectin (Heartgard) 140 reports · 1.2% of its reports
Weight gain after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 23 reports · 0.3% of its reports
Weight gain after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 23 reports · 2.0% of its reports

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