Drug profile

The FDA adverse-event record for Pentobarbital, Phenytoin

185 FDA reports name Pentobarbital, Phenytoin, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#557 of 2,679
by report volume (all drugs)
185
adverse-event reports
74.6%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Pentobarbital, Phenytoin ranks #556 of 2679 by total reports (185) and #28 of 1130 by death-coded share (74.6%). 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)
#556
This drug, reports of 2679
#28
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. Pentobarbital, Phenytoin has 185 reports now versus 185 in that prior snapshot: 0 the same number of (0.0%).

Report change
+0
Death-coded reports
+0
Death-coded share
−0.0 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 Pentobarbital, Phenytoin changes

Signature read: Pentobarbital, Phenytoin's 74.6% 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.
185
Total Reports
138
Deaths Reported
74.6%
Death-coded share of reports

Active Ingredients

Pentobarbital, Phenytoin

Administration Routes

IntravenousUnknownSubcutaneousOralTopicalOtherOphthalmicIntracardiacIntraperitonealIntramuscular

Species Affected

Dog 100
Cat 34
Unknown 20
Human 16
Horse 10
Other 2
Sheep 1
Rabbit 1
Cattle 1

Most Affected Breeds

Unknown 38
Mixed (Dog) 28
Dog (unknown) 25
Domestic (unspecified) 15
Crossbred Canine/dog 13
Cat (unknown) 13
Retriever - Labrador 9
Shepherd Dog - German 4
Rottweiler 4
Retriever - Golden 3

Most Reported Reactions

Death by euthanasia 80
INEFFECTIVE, EUTHANASIA 74
INEFFECTIVE, DELAYED EFFECT 64
Unclassifiable adverse event 23
Accidental exposure 22
Injection site pain 8
Vocalisation 7
Solution, Abnormal 6
Vials, Damaged 5
Vials, Abnormal 5
Hypothermia 4
Eye irritation 4

Outcome Breakdown

Died
132 (95.0%)
Euthanized
6 (4.3%)
Outcome Unknown
1 (0.7%)

Pentobarbital, Phenytoin: 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 Pentobarbital, Phenytoin, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

Similar report volume

Nearest other drugs by FDA report count (185 here).

Similar death-coded share

Nearest other drugs by death-coded share (74.6% here), distinct from the volume row.

What to do with this drug

  • Compare Pentobarbital, Phenytoin's report volume and death-coded share against similar drugs nationwide. See similar drugs
  • Read how death-coded share differs from a mortality rate before drawing conclusions. Understanding adverse events
  • Browse the full drug directory to compare report counts across products. All drugs

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 Pentobarbital, Phenytoin (#557 of 2,679 by report volume); death-coded 74.6%. PlainBreed drug row · death-coded share stamp 74.6% · 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 →