Drug profile

The FDA adverse-event record for Ampicillin

607 FDA reports name Ampicillin, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#266 of 2,679
by report volume (all drugs)
607
adverse-event reports
40.0%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Ampicillin ranks #266 of 2679 by total reports (607) and #82 of 1130 by death-coded share (40.0%). 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)
#266
This drug, reports of 2679
#82
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. Ampicillin has 607 reports now versus 596 in that prior snapshot: 11 more (1.8%).

Report change
+11
Death-coded reports
+2
Death-coded share
−0.4 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 Ampicillin changes

Signature read: death-coded report count at 243 is the most distinctive stamp on Ampicillin's FDA AER row.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
607
Total Reports
243
Deaths Reported
40.0%
Death-coded share of reports

Active Ingredients

Ampicillin

Administration Routes

UnknownIntravenousSubcutaneousIntramuscularParenteralOralOther

Species Affected

Dog 461
Cat 121
Cattle 24
Horse 1

Most Affected Breeds

Domestic Shorthair 92
Retriever - Labrador 76
Retriever - Golden 22
Shih Tzu 17
Chihuahua 16
Terrier - Yorkshire 13
Shepherd Dog - German 13
Terrier - Jack Russell 13
Boxer (German Boxer) 13
Crossbred Canine/dog 12

Most Reported Reactions

Vomiting 180
Other abnormal test result NOS 150
Lethargy (see also Central nervous system depression in 'Neurological') 146
Death by euthanasia 136
Anorexia 125
Elevated alanine aminotransferase (ALT) 118
Death 106
Elevated total bilirubin 105
Elevated blood urea nitrogen (BUN) 94
Elevated serum alkaline phosphatase (SAP) 93
Leucocytosis NOS 92
Diarrhoea 90

Outcome Breakdown

Ongoing
194 (31.8%)
Euthanized
136 (22.3%)
Died
107 (17.5%)
Recovered/Normal
97 (15.9%)
Outcome Unknown
73 (12.0%)
Recovered with Sequela
3 (0.5%)

Ampicillin: 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.

High-volume nationwide drug peers

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

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 Ampicillin (#266 of 2,679 by report volume); death-coded 40.0%. PlainBreed drug row · death-coded report count stamp 243 · 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 →