Drug profile

The FDA adverse-event record for Cyclophosphamide

57 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Cyclophosphamide. Species, reactions, and outcomes follow.

#1037 of 2,679
by report volume (all drugs)
57
adverse-event reports
28.1%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Cyclophosphamide ranks #1035 of 2679 by total reports (57) and #135 of 1130 by death-coded share (28.1%). National dual: Milbemycin Oxime + Spinosad is #1 of 2679 drugs by total adverse-event reports (149,624) at death-coded-share rank 965 of 1130 drugs with at least 50 reports (2.3%); separately, Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) is #1 highest death-coded share at 97.8% (report rank #821).

149,624
Milbemycin Oxime + Spinosad reports (#1)
97.8%
Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) death share (#1)
#1035
This drug, reports of 2679
#135
This drug, death share of 1130

Report volume reflects how common a breed or drug is and how often owners and vets file — not actual risk. Death-coded share ranks are limited to entries with enough reports to be meaningful. The two maps do not agree at #1.

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. Cyclophosphamide has 57 reports now versus 55 in that prior snapshot: 2 more (3.6%).

Report change
+2
Death-coded reports
+1
Death-coded share
+0.8 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to Cyclophosphamide changes

Signature read: Cyclophosphamide's 28.1% death-coded share is among the highest in the openFDA drug corpus.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
57
Total Reports
16
Deaths Reported
28.1%
Death-coded share of reports

Active Ingredients

Cyclophosphamide

Administration Routes

UnknownOralIntravenous

Species Affected

Dog 47
Cat 10

Most Affected Breeds

Domestic Shorthair 6
Retriever - Labrador 6
Retriever - Golden 5
Beagle 4
Pit Bull 3
Cat (unknown) 2
Rottweiler 2
Terrier - Bull - American Pit 2
Cattle Dog - Australian (blue heeler, red heeler, Queensland cattledog) 2
Boxer (German Boxer) 2

Most Reported Reactions

Death by euthanasia 14
Vomiting 9
Lack of efficacy - NOS 9
Lethargy (see also Central nervous system depression in 'Neurological') 6
Fever 6
Weight loss 6
Diarrhoea 6
Anorexia 5
Decreased appetite 5
Elevated alanine aminotransferase (ALT) 5
Anaemia NOS 4
Elevated serum alkaline phosphatase (SAP) 4

Outcome Breakdown

Ongoing
20 (35.1%)
Euthanized
14 (24.6%)
Outcome Unknown
12 (21.1%)
Recovered/Normal
9 (15.8%)
Died
2 (3.5%)

Cyclophosphamide: high death-coded share in the FDA AER row

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.

Nationwide drugs with similar profiles

Two openFDA-derived peer sets for Cyclophosphamide, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

Similar report volume

Nearest other drugs by FDA report count (57 here).

Similar death-coded share

Nearest other drugs by death-coded share (28.1% here), distinct from the volume row.

What to do with this drug

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

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

openFDA Animal & Veterinary Adverse Events (FDA CVM) for Cyclophosphamide (#1037 of 2,679 by report volume); death-coded 28.1%. PlainBreed drug row · death-coded share stamp 28.1% · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →