Drug profile

The FDA adverse-event record for Melarsomine Dihydrocloride Injectable 25Mg/Ml

612 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Melarsomine Dihydrocloride Injectable 25Mg/Ml. See the species affected, top reactions, and outcomes below.

612
adverse-event reports
3.8%
death-coded share
Dog
most-reported species
127
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.
612
Total Reports
23
Deaths Reported
3.8%
Death Rate

Active Ingredients

Melarsomine Dihydrocloride Injectable 25Mg/Ml

Administration Routes

IntramuscularUnknownSubcutaneousIntravenous

Species Affected

Dog 502
Unknown 106
Human 3
Other Canids 1

Most Affected Breeds

Unknown 109
Dog (other) 82
Retriever - Labrador 62
Crossbred Canine/dog 33
Dog (unknown) 27
Shepherd Dog - German 19
Boxer (German Boxer) 19
Chihuahua 19
Pit Bull 17
Beagle 17

Most Reported Reactions

INEFFECTIVE, HEARTWORM ADULTS 127
Vials, Damaged 78
Vomiting 67
Lethargy (see also Central nervous system depression in 'Neurological') 61
INEFFECTIVE, HEARTWORM LARVAE 41
Injection site swelling 38
Panting 37
Injection site lump 36
Injection site pain 36
Elevated alanine aminotransferase (ALT) 29
Other abnormal test result NOS 27
Lack of efficacy - NOS 26

Outcome Breakdown

Outcome Unknown
317 (62.4%)
Ongoing
74 (14.6%)
Recovered/Normal
54 (10.6%)
Recovered with Sequela
40 (7.9%)
Died
16 (3.1%)
Euthanized
7 (1.4%)

Melarsomine Dihydrocloride Injectable 25Mg/Ml Adverse Event Insights

612 reports name Melarsomine Dihydrocloride Injectable 25Mg/Ml; 23 recorded a death outcome (3.8% of reported events, not a population-level mortality rate). Active ingredient: Melarsomine Dihydrocloride Injectable 25Mg/Ml. Administration routes: Intramuscular, Unknown, Subcutaneous, Intravenous.

By species: Dog (502 reports), Unknown (106 reports), Human (3 reports). By breed: Unknown (109), Dog (other) (82), Retriever - Labrador (62).

Leading clinical signs: INEFFECTIVE, HEARTWORM ADULTS (127), Vials, Damaged (78), Vomiting (67), Lethargy (see also Central nervous system depression in 'Neurological') (61). Outcome, 508 coded reports: Outcome Unknown leads at 62.4%.

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.