Drug profile

The FDA adverse-event record for Melarsomine Dihydrochloride 50 Mg/ Injection

48 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Melarsomine Dihydrochloride 50 Mg/ Injection. See the species affected, top reactions, and outcomes below.

48
adverse-event reports
4.2%
death-coded share
Dog
most-reported species
20
Lack of efficacy (endoparasite) - heartworm - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
48
Total Reports
2
Deaths Reported
4.2%
Death Rate

Active Ingredients

Melarsomine Dihydrochloride 50 Mg/ Injection

Administration Routes

IntramuscularUnknownIntravenousParenteral

Species Affected

Dog 48

Most Affected Breeds

Beagle 5
Terrier - Bull - American Pit 4
Terrier (unspecified) 3
Retriever - Golden 3
Retriever - Labrador 3
Chihuahua 3
Collie - Border 2
Crossbred Canine/dog 2
Bulldog - French 2
Shepherd Dog - German 2

Most Reported Reactions

Lack of efficacy (endoparasite) - heartworm 20
Vomiting 7
Panting 6
Diarrhoea 5
Shaking 3
Injection site lump 3
Limb weakness 3
Pain NOS 3
Lethargy (see also Central nervous system depression in 'Neurological') 2
Injection site pain 2
Lethargy (see also Central nervous system depression in Neurological) 2
Injection site swelling 2

Outcome Breakdown

Outcome Unknown
31 (64.6%)
Recovered/Normal
8 (16.7%)
Ongoing
7 (14.6%)
Died
2 (4.2%)

Melarsomine Dihydrochloride 50 Mg/ Injection Adverse Event Insights

48 reports name Melarsomine Dihydrochloride 50 Mg/ Injection; 2 recorded a death outcome (4.2% of reported events, not a population-level mortality rate). Active ingredient: Melarsomine Dihydrochloride 50 Mg/ Injection. Administration routes: Intramuscular, Unknown, Intravenous, Parenteral.

By species: Dog (48 reports). By breed: Beagle (5), Terrier - Bull - American Pit (4), Terrier (unspecified) (3).

Leading clinical signs: Lack of efficacy (endoparasite) - heartworm (20), Vomiting (7), Panting (6), Diarrhoea (5). Outcome, 48 coded reports: Outcome Unknown leads at 64.6%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.