Prolonged capillary refill time after Melarsomine (Immiticide) in dogs

The FDA has received 57 reports of prolonged capillary refill time in dogs after Melarsomine. That is 0.3% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

57Reports

60%Marked serious

11%Recovered

11%Died or euthanised

15 daysTypical onset

How soon it started

Same day

12 34%

1–2 days

2 5.7%

3–7 days

2 5.7%

1–4 weeks

6 17%

Over a month

13 37%

How the animals did

Recovered

6 11%

Still unwell when reported

22 39%

Died

6 11%

Not known

23 40%

Problems reported at the same time

28 49%

24 42%

21 37%

16 28%

14 25%

14 25%

13 23%

13 23%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Melarsomine treats adult heartworm infection (a series of injections given by a vet).

Products with this ingredient include Immiticide, Diroban. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Melarsomine cause prolonged capillary refill time in dogs?: 57 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 15 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).

Prolonged capillary refill time with similar medicines

Prolonged capillary refill time after Diphenhydramine 31 reports · 0.7% of its reports

All reported side effects of Melarsomine in dogs · Medicines most reported with prolonged capillary refill time