Hyperpigmentation after Melarsomine (Immiticide) in dogs

26 reports to the FDA describe hyperpigmentation in dogs given Melarsomine. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

26Reports

31%Marked serious

3.8%Recovered

0.0%Died or euthanised

30 daysTypical onset

How soon it started

Same day

3 25%

1–2 days

1 8.3%

3–7 days

0 0.0%

1–4 weeks

5 42%

Over a month

3 25%

How the animals did

Recovered

1 3.8%

Still unwell when reported

7 27%

Not known

18 69%

Problems reported at the same time

Hair loss

13 50%

Injection site reaction

9 35%

Itching

7 27%

Skin redness

5 19%

Skin rash or irritation

4 15%

Lethargy

3 12%

Crust

3 12%

Cough

2 7.7%

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 hyperpigmentation in dogs?: 26 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 30 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).

Hyperpigmentation with similar medicines

Hyperpigmentation after Estriol 25 reports · 1.2% of its reports
Hyperpigmentation after Rabacfosadine 35 reports · 5.3% of its reports

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