Arched back after Melarsomine (Immiticide) in dogs

The FDA has received 24 reports of arched back in dogs after Melarsomine. That is 0.1% 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.

24Reports

75%Marked serious

13%Recovered

0.0%Died or euthanised

1 daysTypical onset

How soon it started

Same day

11 50%

1–2 days

1 4.5%

3–7 days

0 0.0%

1–4 weeks

5 23%

Over a month

5 23%

How the animals did

Recovered

3 13%

Still unwell when reported

7 29%

Not known

14 58%

Problems reported at the same time

Breathing problems

11 46%

Pain

10 42%

Loss of appetite

7 29%

Restlessness or agitation

5 21%

Injection site reaction

5 21%

Vocalising

4 17%

Anxiety

4 17%

Drooling

4 17%

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 arched back in dogs?: 24 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).

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