Doxycycline

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3,706 adverse event reports submitted to the FDA

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
3,706
Total Reports
530
Deaths Reported
1430.0%
Death Rate

Active Ingredients

Doxycycline

Administration Routes

OralUnknownIntravenousTopicalSubcutaneousPeriodontalIntramuscularAuricular (Otic)OphthalmicParenteral

Species Affected

Dog 3,469
Cat 207
Unknown 15
Horse 14
Human 1

Most Affected Breeds

Retriever - Labrador 470
Crossbred Canine/dog 193
Shepherd Dog - German 190
Beagle 165
Terrier - Bull - American Pit 150
Chihuahua 146
Retriever - Golden 126
Domestic Shorthair 122
Dog (unknown) 104
Terrier (unspecified) 100

Most Reported Reactions

Lack of efficacy (endoparasite) - heartworm 1,098
Vomiting 552
Lethargy (see also Central nervous system depression in 'Neurological') 458
Other abnormal test result NOS 340
Death by euthanasia 297
Anorexia 288
Elevated alanine aminotransferase (ALT) 252
Diarrhoea 249
Lack of efficacy - NOS 238
Death 220
Cough 211
Leucocytosis NOS 208

Outcome Breakdown

Ongoing
1,773 (48.1%)
Outcome Unknown
822 (22.3%)
Recovered/Normal
533 (14.5%)
Euthanized
291 (7.9%)
Died
240 (6.5%)
Recovered with Sequela
27 (0.7%)

Data Summary

Metric Value
Total adverse event reports 3,706
Reports involving death 530
Case-fatality rate (reported events) 1430.0%
Distinct species in reports 5
Distinct breeds in reports 20
Distinct reactions reported 20
Active ingredients on file 1

Source: FDA Center for Veterinary Medicine — Adverse Event Reporting (CVM AER). Counts reflect voluntary reports only.

Doxycycline Adverse Event Insights

The FDA Center for Veterinary Medicine database currently holds 3,706 adverse event reports referencing Doxycycline, including 530 reports in which the animal died — a 1430.0% case-fatality figure among reported events only, not a population-level mortality rate. Active ingredient on file: Doxycycline. Reported administration routes include Oral, Unknown, Intravenous, Topical. These numbers reflect voluntary submissions from pet owners, veterinarians, and manufacturers and therefore under-represent mild events and over-represent severe ones — a pattern the FDA has documented repeatedly for pharmacovigilance datasets.

The species most frequently named in Doxycycline reports are Dog (3,469 reports), Cat (207 reports), Unknown (15 reports), with Dog accounting for the largest share. Within those species, Retriever - Labrador (470), Crossbred Canine/dog (193), Shepherd Dog - German (190) appear most often — though breed popularity and ownership density shape these counts as much as any drug-specific sensitivity. This distribution matters because the same active ingredient can behave very differently across body sizes, ages, and species physiology.

The most commonly reported clinical signs associated with Doxycycline are Lack of efficacy (endoparasite) - heartworm (1,098), Vomiting (552), Lethargy (see also Central nervous system depression in 'Neurological') (458), Other abnormal test result NOS (340). Of the 3,686 reports with a coded outcome, Ongoing is the leading category at 48.1%. Because FDA adverse event data describes correlation rather than causation, these figures are best used to frame informed questions with a veterinarian and to compare reporting patterns across related products — not as a standalone safety verdict on Doxycycline.

Source: FDA Center for Veterinary Medicine — Adverse Event Reports FDA Center for Veterinary Medicine — Adverse Event Reports Data reflects voluntary submissions and may not represent actual incidence rates

Related

Data sourced from official AKC, AVMA, ACVO, and breed-club veterinary references. See our methodology for details. Retrieved and formatted by PlainBreed Editorial