Drug profile

The FDA adverse-event record for B12

27 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference B12. See the species affected, top reactions, and outcomes below.

27
adverse-event reports
14.8%
death-coded share
Cat
most-reported species
8
Vomiting - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
27
Total Reports
4
Deaths Reported
14.8%
Death Rate

Active Ingredients

B12

Administration Routes

UnknownSubcutaneousOralParenteral

Species Affected

Cat 14
Dog 12
Human 1

Most Affected Breeds

Domestic Shorthair 8
Domestic Mediumhair 3
Crossbred Canine/dog 2
Mountain Cur 2
Terrier - Yorkshire 2
Mountain Dog - Bernese 2
Schnauzer - Miniature 1
Unknown 1
Spitz - German Pomeranian 1
Retriever - Golden 1

Most Reported Reactions

Vomiting 8
Diarrhoea 5
Weight loss 5
Decreased appetite 5
Ataxia 5
Elevated alanine aminotransferase (ALT) 5
Lethargy (see also Central nervous system depression in Neurological) 5
Application site reddening 3
Twitching 3
Seizure NOS 3
Anaemia NOS 3
Bloody diarrhoea 3

Outcome Breakdown

Ongoing
11 (40.7%)
Outcome Unknown
8 (29.6%)
Recovered/Normal
4 (14.8%)
Died
2 (7.4%)
Euthanized
2 (7.4%)

B12 Adverse Event Insights

27 reports name B12; 4 recorded a death outcome (14.8% of reported events, not a population-level mortality rate). Active ingredient: B12. Administration routes: Unknown, Subcutaneous, Oral, Parenteral.

By species: Cat (14 reports), Dog (12 reports), Human (1 reports). By breed: Domestic Shorthair (8), Domestic Mediumhair (3), Crossbred Canine/dog (2).

Leading clinical signs: Vomiting (8), Diarrhoea (5), Weight loss (5), Decreased appetite (5). Outcome, 27 coded reports: Ongoing leads at 40.7%.

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.

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

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.