Gabapentin and pregabalin for pet pain: a US-China regulatory contrast
Gabapentin and pregabalin are two anticonvulsant/analgesic drugs that began life in human medicine and are now fixtures of veterinary pain management. Both are used off-label or as part of multimodal analgesia in dogs and cats. This article was planned as a US–China regulatory contrast. On disk, only the US FDA adverse-event (ADE) source topics were present; the China MOA announcement topics and the FDA Green Book topic named in the brief were not found on disk at writing time. Per the data rules of this project, missing sources are never substituted by second-hand or invented text. So this article delivers the US half in full from first-hand FDA data, and flags the China half as pending rather than fabricating it.
The US side: FDA adverse-event reports
The US picture comes from the FDA Center for Veterinary Medicine (CVM) adverse event report database, accessed through openFDA animalandveterinary/event.json. The two source topics in this article were pulled on 2026-07-21 (gabapentin) and 2026-07-22 (pregabalin); a second gabapentin topic pulled 2026-07-22 records the identical total, so the counts below are stable across the pull window. Both topics state: "Counts are report-level: one report may list multiple reactions and multiple animals, so figures are not additive and do not imply causation."
The headline cumulative totals are:
- Gabapentin: 10445 total reports.
- Pregabalin: 207 total reports.
The gap is large — gabapentin appears in roughly fifty times as many reports as pregabalin — which is consistent with gabapentin's far longer and broader use in companion-animal practice, while pregabalin remains the smaller, newer actor in the veterinary space.
Snapshot, cumulativeness, and the "reported ≠ causal" rule
These counts are cumulative as of the openFDA pull dated 2026-07-21 / 2026-07-22. They are not annual rates and they are not incidence proportions; they are the running tally of reports lodged in the FDA CVM database up to that snapshot.
Explicit disclaimer: ADE reports are submitted by veterinarians, pet owners, manufacturers, and others. A report means a reaction was observed and recorded, not that the drug caused it. The source topics themselves state the figures "do not imply causation." Correlation between a drug and a reported event is not evidence of a causal link. Anyone reading "10,445 gabapentin reports" as "gabapentin caused harm in 10,445 animals" is misreading the data.
A second, easily-missed point lives in the reaction terms. Under VEDDRA (the veterinary dictionary for drug-related adverse events), "Lack of efficacy" terms denote product-performance reports, not adverse reactions. Both topics surface lack-of-efficacy entries — for gabapentin, "Lack of efficacy - NOS 877"; for pregabalin, "Lack of efficacy - NOS 42". These are reports that the product did not work as expected, not that the animal was harmed. They must not be lumped into a "side-effect" tally.
Species breakdown
Who are these reports about? The species splits are striking and tell their own story.
Gabapentin reports by species (top entries):
- Dog 8575
- Cat 1836
- Human 17
- Horse 3
- Ferret 2
- Goat 2
Pregabalin reports by species (top entries):
- Cat 127
- Dog 61
- Human 4
Two things stand out. First, dogs dominate the gabapentin record (8,575 of 10,445, or about 82%), with cats a distant second — the mirror of how gabapentin is most often reached for in canine pain and seizure management. Second, the human entries (17 for gabapentin, 4 for pregabalin) are a reminder that this is an open reporting system: accidental exposure, household cross-contact, or a human reporter can land a human case in an animal database. They are not veterinary patients.
Pregabalin's species order is the reverse of gabapentin's at the top — Cat 127 ahead of Dog 61 — though the absolute numbers are small enough that this ordering should be read with caution rather than as a strong clinical signal.
Reaction profile
The top reported reactions (VEDDRA terms) differ in emphasis between the two drugs.
For pregabalin, the leading entries are:
- Lack of efficacy - NOS 42
- Lethargy (see also Central nervous system depression in Neurological) 31
- Ataxia 24
- Death by euthanasia 18
- Vomiting 17
- Overdose 16
- Wobbliness 15
- Medication error NOS 13
- Seizure NOS 13
- Intentional misuse 11
For gabapentin, the leading entries are:
- Vomiting 1597
- Diarrhoea 1170
- Death by euthanasia 1157
- Lethargy (see also Central nervous system depression in Neurological) 1113
- Not eating 916
- Lack of efficacy - NOS 877
- Decreased appetite 688
- Elevated alanine aminotransferase (ALT) 673
- Ataxia 641
- Lethargy (see also Central nervous system depression in 'Neurological') 634
Both profiles are dominated by the classic gabapentinoid signature: sedation and ataxia (wobbliness, lethargy, "Central nervous system depression"), plus gastrointestinal signs (vomiting, diarrhoea, not eating, decreased appetite). That pattern is exactly what clinicians expect from this drug class — the reports largely corroborate the known adverse-effect profile rather than surfacing surprises.
Two entries deserve a careful read. "Death by euthanasia" appears high on both lists (gabapentin 1157; pregabalin 18). This is a reported outcome, frequently recorded when a severely ill animal is euthanised; it is not, by itself, evidence the drug was fatal. And "Overdose 16" plus "Intentional misuse 11" and "Medication error NOS 13" in the pregabalin topic point to a human-side problem — gabapentinoids are controlled-substance-adjacent in people, and misuse, accidental overdose, and dosing errors show up in the veterinary record too.
"Elevated alanine aminotransferase (ALT) 673" in the gabapentin topic is the one liver-enzyme signal worth a clinician's eye, but as with every entry here, a report is an observation, not a proven hepatic injury attributed to the drug.
The China half: pending, not invented
The original brief asked for a contrast with China's Ministry of Agriculture and Rural Affairs (MOA) new-veterinary-drug announcements — Announcement 1022 and Announcement 1038 — and for the Chinese drug name to be written alongside the INN whenever a China source was cited (for example, the CN rendering of pregabalin/gabapentin as it appears in Ann 1038, plus the INN). The corresponding source topics (cn_moa_ann1022_new_veterinary_drugs_pet, cn_moa_ann1038_new_veterinary_drugs_pet) were not present on disk at writing time, and neither was the FDA Green Book topic (fda_green_book_recent_approvals_pet_drug_2024_2026).
Because this project forbids substituting second-hand text or agent-written summaries for first-hand source documents, the China MOA contrast and the CN/INN dual-naming requirement cannot be satisfied here without fabrication — and fabrication is explicitly prohibited. The China side is therefore left pending. When the Ann 1022 / Ann 1038 topics are collected and verified on disk, the dual-named China section can be written against them, and the frontmatter source_topics updated to reflect the topics actually used. Until then, no Chinese drug name or approval figure is asserted in this article.
What the US data does and does not tell us
Taken together, the two FDA topics give a clear, first-hand view of how gabapentin and pregabalin behave in the real-world US veterinary record: gabapentin is the workhorse with a deep, sedation-and-GI-dominated report profile; pregabalin is the smaller, newer entrant. Both confirm the expected gabapentinoid signature. Neither tells us anything about causation, and both contain lack-of-efficacy entries that are not adverse reactions at all.
The honest limit of this article is also its strength: every number above is a verbatim substring of a first-hand FDA source, the snapshot date is stated, and the "reported ≠ causal" boundary is drawn explicitly. The China contrast will have to earn its place the same way — from sources on disk, not from assumption.
Sources
Every figure and quoted phrase above is a verbatim substring of one of the following source topics (all confirmed present on disk). Caliber: first-hand FDA CVM adverse-event data (openFDA animalandveterinary/event.json), C1-verified by substring match in the topic files.
ade_gabapentin_adverse_events— Gabapentin: 10445 total; species Dog 8575 / Cat 1836 / Human 17 / Horse 3 / Ferret 2 / Goat 2; top reactions Vomiting 1597, Diarrhoea 1170, Death by euthanasia 1157, Lethargy 1113, Not eating 916, Lack of efficacy - NOS 877, Decreased appetite 688, Elevated ALT 673, Ataxia 641; pulled 2026-07-21 (identical total in a 2026-07-22 pull). First-hand FDA openFDA ADE; "Lack of efficacy terms denote product-performance reports, not adverse reactions."ade_pregabalin_adverse_events— Pregabalin: 207 total; species Cat 127 / Dog 61 / Human 4; top reactions Lack of efficacy - NOS 42, Lethargy 31, Ataxia 24, Death by euthanasia 18, Vomiting 17, Overdose 16, Wobbliness 15, Medication error NOS 13, Seizure NOS 13, Intentional misuse 11; pulled 2026-07-22. First-hand FDA openFDA ADE.
Topics named in the brief but absent on disk — not used, not fabricated:
cn_moa_ann1022_new_veterinary_drugs_pet— not found on disk; China MOA Ann 1022 contrast pending.cn_moa_ann1038_new_veterinary_drugs_pet— not found on disk; China MOA Ann 1038 contrast and CN/INN dual naming pending.fda_green_book_recent_approvals_pet_drug_2024_2026— not found on disk; not used.