Drug profile

The FDA adverse-event record for Melarsomine Dihydrochloride Injection

5,095 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Melarsomine Dihydrochloride Injection. See the species affected, top reactions, and outcomes below.

5,095
adverse-event reports
3.9%
death-coded share
Dog
most-reported species
1,260
INEFFECTIVE, HEARTWORM ADULTS - 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.
5,095
Total Reports
198
Deaths Reported
3.9%
Death Rate

Active Ingredients

Melarsomine Dihydrochloride Injection

Administration Routes

IntramuscularUnknownSubcutaneousOralOphthalmicParenteralIntravenous

Species Affected

Dog 4,570
Unknown 507
Human 18

Most Affected Breeds

Crossbred Canine/dog 681
Retriever - Labrador 607
Unknown 541
Dog (unknown) 304
Pit Bull 249
Shepherd Dog - German 244
Dog (other) 240
Beagle 207
Chihuahua 174
Boxer (German Boxer) 170

Most Reported Reactions

INEFFECTIVE, HEARTWORM ADULTS 1,260
INEFFECTIVE, HEARTWORM LARVAE 627
Vomiting 595
Injection site swelling 487
Cardiac disorder NOS 458
Lethargy (see also Central nervous system depression in 'Neurological') 442
Pain NOS 330
Vials, Damaged 325
Injection site pain 320
Panting 312
Other abnormal test result NOS 299
Injection site lump 297

Outcome Breakdown

Outcome Unknown
2,939 (64.0%)
Recovered/Normal
613 (13.3%)
Ongoing
518 (11.3%)
Recovered with Sequela
326 (7.1%)
Died
138 (3.0%)
Euthanized
60 (1.3%)

Melarsomine Dihydrochloride Injection Adverse Event Insights

5,095 reports name Melarsomine Dihydrochloride Injection; 198 recorded a death outcome (3.9% of reported events, not a population-level mortality rate). Active ingredient: Melarsomine Dihydrochloride Injection. Administration routes: Intramuscular, Unknown, Subcutaneous, Oral.

By species: Dog (4,570 reports), Unknown (507 reports), Human (18 reports). By breed: Crossbred Canine/dog (681), Retriever - Labrador (607), Unknown (541).

Leading clinical signs: INEFFECTIVE, HEARTWORM ADULTS (1,260), INEFFECTIVE, HEARTWORM LARVAE (627), Vomiting (595), Injection site swelling (487). Outcome, 4,594 coded reports: Outcome Unknown leads at 64.0%.

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.