Drug profile

The FDA adverse-event record for Lactulose

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

#437 of 2,679
by report volume (all drugs)
285
adverse-event reports
20.4%
death-coded share
Cat
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Lactulose ranks #436 of 2679 by total reports (285) and #238 of 1130 by death-coded share (20.4%). 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)
#436
This drug, reports of 2679
#238
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. Lactulose has 285 reports now versus 276 in that prior snapshot: 9 more (3.3%).

Report change
+9
Death-coded reports
+4
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 Lactulose changes

Signature read: death-coded report count at 58 is the most distinctive stamp on Lactulose'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.
285
Total Reports
58
Deaths Reported
20.4%
Death-coded share of reports

Active Ingredients

Lactulose

Administration Routes

OralUnknownRectalOtherSubcutaneous

Species Affected

Cat 193
Dog 90
Human 1
Other Birds 1

Most Affected Breeds

Domestic Shorthair 124
Terrier - Yorkshire 19
Domestic Longhair 12
Domestic Mediumhair 11
Chihuahua 8
Cat (other) 8
Cat (unknown) 7
Retriever - Labrador 5
Schnauzer - Miniature 5
Shepherd Dog - German 5

Most Reported Reactions

Vomiting 48
Lethargy (see also Central nervous system depression in 'Neurological') 45
Death by euthanasia 33
Anorexia 32
Constipation 31
Weight loss 29
Other abnormal test result NOS 27
Diarrhoea 26
Seizure NOS 25
Decreased appetite 25
Lack of efficacy - NOS 25
Death 24

Outcome Breakdown

Ongoing
104 (36.5%)
Recovered/Normal
63 (22.1%)
Outcome Unknown
60 (21.1%)
Euthanized
33 (11.6%)
Died
25 (8.8%)

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

Similar death-coded share

Nearest other drugs by death-coded share (20.4% 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 Lactulose (#437 of 2,679 by report volume); death-coded 20.4%. PlainBreed drug row · death-coded report count stamp 58 · 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 →