Lethargy after Selamectin (Revolution) in dogs

2,964 reports to the FDA describe lethargy in dogs given Selamectin. That is 10% of all reports for this medicine, compared with 11% across reports for all dog medicines.

2,964Reports

8.8%Marked serious

12%Recovered

7.7%Died or euthanised

Same dayTypical onset

How soon it started

Same day

515 52%

1–2 days

252 25%

3–7 days

88 8.9%

1–4 weeks

54 5.4%

Over a month

84 8.5%

How the animals did

Recovered

356 12%

Recovered with lasting effects

5 0.2%

Still unwell when reported

377 13%

Died

199 6.7%

Euthanised

30 1.0%

Not known

1,997 67%

Problems reported at the same time

1,102 37%

1,045 35%

599 20%

351 12%

244 8.2%

232 7.8%

188 6.3%

185 6.2%

Age of the animals

Under 1 year

663

1–3 years

855

4–7 years

706

8–11 years

445

12+ years

193

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 lethargy in dogs?: 2,964 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 the same 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).

Lethargy with similar medicines

Lethargy after Ivermectin + Pyrantel (Heartgard Plus) 7,391 reports · 5.0% of its reports
Lethargy after Milbemycin Oxime + Spinosad (Trifexis) 19,835 reports · 15% of its reports
Lethargy after Moxidectin (ProHeart 6) 6,640 reports · 13% of its reports
Lethargy after Milbemycin Oxime + Praziquantel (Interceptor Plus) 2,407 reports · 7.6% of its reports
Lethargy after Milbemycin Oxime (Interceptor) 2,528 reports · 8.5% of its reports
Lethargy after Ivermectin (Heartgard) 1,488 reports · 12% of its reports
Lethargy after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 969 reports · 11% of its reports
Lethargy after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 135 reports · 12% of its reports
Lethargy after Ivermectin + Praziquantel 35 reports · 17% of its reports
Lethargy after Moxidectin + Praziquantel 21 reports · 28% of its reports

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