Drug profile

The FDA adverse-event record for Doxycyline

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

31
adverse-event reports
16.1%
death-coded share
Dog
most-reported species
6
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.
31
Total Reports
5
Deaths Reported
16.1%
Death Rate

Active Ingredients

Doxycyline

Administration Routes

OralUnknown

Species Affected

Dog 29
Cat 1
Horse 1

Most Affected Breeds

Retriever - Labrador 5
Crossbred Canine/dog 2
Cattle Dog - Australian (blue heeler, red heeler, Queensland cattledog) 2
Poodle - Standard 2
Terrier - Bull - Staffordshire 2
Pointing Dog - Hungarian Short-haired (Vizsla) 2
Collie - Border 1
Shepherd Dog - Australian 1
Domestic Longhair 1
Deutsche Dogge, Great Dane 1

Most Reported Reactions

Vomiting 6
Lack of efficacy (endoparasite) - heartworm 6
Ataxia 5
Death by euthanasia 4
Diarrhoea 4
Elevated alanine aminotransferase (ALT) 4
Not eating 4
Decreased appetite 3
Abnormal pupil light reflex 3
Weight loss 3
Lack of efficacy (endoparasite) - hookworm 3
Lack of efficacy (bacteria) - Borrelia 3

Outcome Breakdown

Outcome Unknown
15 (48.4%)
Recovered/Normal
6 (19.4%)
Ongoing
5 (16.1%)
Euthanized
3 (9.7%)
Died
2 (6.5%)

Doxycyline Adverse Event Insights

31 reports name Doxycyline; 5 recorded a death outcome (16.1% of reported events, not a population-level mortality rate). Active ingredient: Doxycyline. Administration routes: Oral, Unknown.

By species: Dog (29 reports), Cat (1 reports), Horse (1 reports). By breed: Retriever - Labrador (5), Crossbred Canine/dog (2), Cattle Dog - Australian (blue heeler, red heeler, Queensland cattledog) (2).

Leading clinical signs: Vomiting (6), Lack of efficacy (endoparasite) - heartworm (6), Ataxia (5), Death by euthanasia (4). Outcome, 31 coded reports: Outcome Unknown leads at 48.4%.

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.