Abnormal ultrasound finding after Selamectin (Revolution) in dogs

The FDA has received 40 reports of abnormal ultrasound finding in dogs after Selamectin. That is 0.1% of all reports for this medicine, compared with 0.5% across reports for all dog medicines, so it is reported less often than average with this medicine.

40Reports

40%Marked serious

2.5%Recovered

38%Died or euthanised

13 daysTypical onset

How soon it started

Same day

5 29%

1–2 days

2 12%

3–7 days

1 5.9%

1–4 weeks

3 18%

Over a month

6 35%

How the animals did

Recovered

1 2.5%

Still unwell when reported

13 33%

Died

10 25%

Euthanised

5 13%

Not known

11 28%

Problems reported at the same time

20 50%

19 48%

18 45%

18 45%

15 38%

12 30%

Abnormal radiograph finding

10 25%

Diarrhea

9 23%

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 abnormal ultrasound finding in dogs?: 40 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 13 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).

Abnormal ultrasound finding with similar medicines

Abnormal ultrasound finding after Ivermectin + Pyrantel (Heartgard Plus) 203 reports · 0.1% of its reports
Abnormal ultrasound finding after Milbemycin Oxime + Spinosad (Trifexis) 240 reports · 0.2% of its reports
Abnormal ultrasound finding after Moxidectin (ProHeart 6) 268 reports · 0.5% of its reports
Abnormal ultrasound finding after Milbemycin Oxime + Praziquantel (Interceptor Plus) 67 reports · 0.2% of its reports
Abnormal ultrasound finding after Milbemycin Oxime (Interceptor) 59 reports · 0.2% of its reports
Abnormal ultrasound finding after Ivermectin (Heartgard) 57 reports · 0.5% of its reports

All reported side effects of Selamectin in dogs · Medicines most reported with abnormal ultrasound finding