Drug profile

The FDA adverse-event record for Chlorambucil

91 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Chlorambucil. See the species affected, top reactions, and outcomes below.

91
adverse-event reports
23.1%
death-coded share
Cat
most-reported species
15
Death by euthanasia - 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.
91
Total Reports
21
Deaths Reported
23.1%
Death Rate

Active Ingredients

Chlorambucil

Administration Routes

UnknownOral

Species Affected

Cat 62
Dog 29

Most Affected Breeds

Domestic Shorthair 31
Domestic Longhair 6
Retriever - Labrador 5
Domestic Mediumhair 5
Persian 4
Shih Tzu 3
Maine Coon 3
Cat (other) 3
Crossbred Canine/dog 3
American Shorthair 2

Most Reported Reactions

Death by euthanasia 15
Vomiting 13
Lack of efficacy - NOS 11
Other abnormal test result NOS 10
Weight loss 10
Anorexia 9
Lethargy (see also Central nervous system depression in 'Neurological') 8
Diarrhoea 8
Behavioural disorder NOS 6
Anaemia NOS 5
Decreased appetite 5
Staggering 5

Outcome Breakdown

Ongoing
41 (45.1%)
Recovered/Normal
17 (18.7%)
Euthanized
16 (17.6%)
Outcome Unknown
11 (12.1%)
Died
5 (5.5%)
Recovered with Sequela
1 (1.1%)

Chlorambucil Adverse Event Insights

91 reports name Chlorambucil; 21 recorded a death outcome (23.1% of reported events, not a population-level mortality rate). Active ingredient: Chlorambucil. Administration routes: Unknown, Oral.

By species: Cat (62 reports), Dog (29 reports). By breed: Domestic Shorthair (31), Domestic Longhair (6), Retriever - Labrador (5).

Leading clinical signs: Death by euthanasia (15), Vomiting (13), Lack of efficacy - NOS (11), Other abnormal test result NOS (10). Outcome, 91 coded reports: Ongoing leads at 45.1%.

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.