Leucopenia after Selamectin (Revolution) in dogs

The FDA has received 47 reports of leucopenia in dogs after Selamectin. That is 0.2% of all reports for this medicine, compared with 0.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

47Reports

15%Marked serious

2.1%Recovered

28%Died or euthanised

1 daysTypical onset

How soon it started

Same day

2 18%

1–2 days

4 36%

3–7 days

2 18%

1–4 weeks

0 0.0%

Over a month

3 27%

How the animals did

Recovered

1 2.1%

Still unwell when reported

12 26%

Died

13 28%

Not known

21 45%

Problems reported at the same time

23 49%

22 47%

21 45%

19 40%

16 34%

15 32%

15 32%

12 26%

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 leucopenia 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 1 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).

Leucopenia with similar medicines

Leucopenia after Ivermectin + Pyrantel (Heartgard Plus) 100 reports · 0.1% of its reports
Leucopenia after Milbemycin Oxime + Spinosad (Trifexis) 109 reports · 0.1% of its reports
Leucopenia after Moxidectin (ProHeart 6) 198 reports · 0.4% of its reports
Leucopenia after Milbemycin Oxime + Praziquantel (Interceptor Plus) 25 reports · 0.1% of its reports
Leucopenia after Milbemycin Oxime (Interceptor) 40 reports · 0.1% of its reports
Leucopenia after Ivermectin (Heartgard) 35 reports · 0.3% of its reports

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