Pulmonary thromboembolism after Melarsomine (Immiticide) in dogs

40 reports to the FDA describe pulmonary thromboembolism in dogs given Melarsomine. That is 0.2% of all reports for this medicine, compared with 0.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

40Reports

95%Marked serious

23%Recovered

18%Died or euthanised

23 daysTypical onset

How soon it started

Same day

4 12%

1–2 days

3 8.8%

3–7 days

3 8.8%

1–4 weeks

13 38%

Over a month

11 32%

How the animals did

Recovered

8 20%

Recovered with lasting effects

1 2.5%

Still unwell when reported

14 35%

Died

4 10%

Euthanised

3 7.5%

Not known

10 25%

Problems reported at the same time

Breathing problems

13 33%

Abnormal radiograph finding

13 33%

10 25%

7 18%

6 15%

5 13%

5 13%

4 10%

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 pulmonary thromboembolism 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 23 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).

All reported side effects of Melarsomine in dogs · Medicines most reported with pulmonary thromboembolism