Drug profile

The FDA adverse-event record for Theophylline

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

#564 of 2,679
by report volume (all drugs)
181
adverse-event reports
19.9%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Theophylline ranks #563 of 2679 by total reports (181) and #247 of 1130 by death-coded share (19.9%). 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)
#563
This drug, reports of 2679
#247
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. Theophylline has 181 reports now versus 178 in that prior snapshot: 3 more (1.7%).

Report change
+3
Death-coded reports
+0
Death-coded share
−0.3 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 Theophylline changes

Signature read: death-coded report count at 36 is the most distinctive stamp on Theophylline'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.
181
Total Reports
36
Deaths Reported
19.9%
Death-coded share of reports

Active Ingredients

Theophylline

Administration Routes

OralUnknown

Species Affected

Dog 173
Cat 8

Most Affected Breeds

Chihuahua 22
Crossbred Canine/dog 13
Retriever - Labrador 11
Maltese 10
Pug 8
Beagle 8
Spitz - German Pomeranian 7
Shepherd Dog - Australian 7
Terrier - Yorkshire 7
Dachshund (unspecified) 7

Most Reported Reactions

Vomiting 38
Lethargy (see also Central nervous system depression in 'Neurological') 29
Death by euthanasia 21
Cough 21
Other abnormal test result NOS 18
Decreased appetite 17
Abnormal radiograph finding 17
Diarrhoea 15
Behavioural disorder NOS 15
Emesis 15
Elevated blood urea nitrogen (BUN) 14
Death 14

Outcome Breakdown

Recovered/Normal
51 (28.5%)
Ongoing
50 (27.9%)
Outcome Unknown
40 (22.3%)
Euthanized
21 (11.7%)
Died
15 (8.4%)
Recovered with Sequela
2 (1.1%)

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

Similar report volume

Nearest other drugs by FDA report count (181 here).

Similar death-coded share

Nearest other drugs by death-coded share (19.9% 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 Theophylline (#564 of 2,679 by report volume); death-coded 19.9%. PlainBreed drug row · death-coded report count stamp 36 · 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 →