May 2003: adverse event reports received

1,143 reports in the openFDA release of 28 Sep 2026

Read this first · FDA's caveat, in its words

An API dataset query result cannot be used to estimate the risk associated with the product or compare one drug or device product with another. When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event. This dataset should not be the sole source of information for clinical decision-making or other assumptions about the safety or effectiveness of a product. The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources. FDA Center for Veterinary Medicine

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated. We may limit or otherwise restrict your access to the API in line with our Terms of Service.

Not veterinary advice. This site lists what was reported to FDA. For an animal that is unwell, contact a veterinarian.

1,143reports received

1,795same month a year earlier-36%

1,118monthly average, preceding 12 months

71.9%concern dogscats 4.2%

FDA's database holds 1,143 adverse event reports received in May 2003, against 1,795 in the same month a year earlier and a monthly average of 1,118 over the preceding 12 months.

71.9% of the month's reports concern dogs, 4.2% cats and 2.5% horses; the rest concern other species, exposed people, or give no species.

By active ingredient, the drugs named most often were moxidectin (261), selegiline hydrochloride (191) and selamectin (134), and the terms listed most often were vomiting (190), depression (127) and ineffective, heartworm larvae (122). Report volume has a seasonal shape, with more reports in the warmer months when parasite products are in heavier use.

The months around it

Drugs named most often, by active ingredient

Active ingredients recorded for the drug	Reports	Share of the month's reports
Moxidectin	261	22.8%
Selegiline Hydrochloride	191	16.7%
Selamectin	134	11.7%
Deracoxib	110	9.6%
Carprofen	55	4.8%
Tilmicosin Phosphate	29	2.5%
Enrofloxacin	25	2.2%
Ivermectin	24	2.1%
Ivermectin + Pyrantel Pamoate	20	1.7%
Melarsomine Dihydrochloride	20	1.7%
Milbemycin Oxime	18	1.6%
Amoxicillin	17	1.5%
Tepoxalin	16	1.4%
Etodolac	15	1.3%
Tylosin	14	1.2%

Ordered by report count, which follows how widely each drug was in use. FDA states that these data cannot be used to estimate risk or to compare one product with another. Brand and manufacturer names are masked by FDA in these records.

Signs listed most often

Vomiting16.6%190
Depression[dull, quiet or withdrawn]11.1%127
Ineffective, heartworm larvae[legacy FDA term: the product did not have the expected effect (heartworm larvae)]10.7%122
Anorexia[not eating]9.4%107
Death8.3%95
Diarrhoea[diarrhea]7.5%86
Anaphylaxis[sudden severe allergic-type reaction]7.2%82
Accidental exposure[exposure that was not intended]5.2%59
Facial oedema[swollen face]4%46
Ataxia[unsteady, uncoordinated movement]3.8%44
Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]3.8%44
Fever3.8%43
Death by euthanasia[the animal was euthanized]3.7%42
Unclassifiable adverse event[event that fits no dictionary term]3.6%41
Elevated blood urea nitrogen (BUN)[a kidney value above the normal range]3.4%39

Single ingredients, pooled

Moxidectin22.8%261

Selegiline Hydrochloride16.7%191

Selamectin11.7%134

Deracoxib9.6%110

Carprofen4.8%55

Ivermectin3.8%44

Tilmicosin Phosphate2.5%29

Enrofloxacin2.4%27

Pyrantel Pamoate2.4%27

Melarsomine Dihydrochloride1.7%20

Milbemycin Oxime1.7%19

Amoxicillin1.6%18

Species

Dog71.9%822

Cat4.2%48

Horse2.5%29

Other or not given21.3%244

Questions about May 2003

How many animal drug adverse event reports did FDA receive in May 2003?

1,143 reports are in the openFDA release of 28 Sep 2026. The same month a year earlier has 1,795.

Which drugs were named most often?

By active ingredient: moxidectin (261), selegiline hydrochloride (191), selamectin (134), deracoxib (110) and carprofen (55). Brands are masked in the public data.

Which signs were listed most often?

vomiting (190), depression (127), ineffective, heartworm larvae (122), anorexia (107) and death (95).

Can the count for a month still change?

Yes. FDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Older months change little.

Does a busy month mean something went wrong that month?

Not by itself. The date is when FDA received the report, not when the event happened, and volume follows season, product launches and publicity. FDA states that "there is no certainty that the reported drug or device caused the adverse event" and that the event "may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources."

Where this comes from. Counts are built from the openFDA Animal & Veterinary adverse event bulk files released 28 Sep 2026, which hold reports FDA's Center for Veterinary Medicine received through 31 Mar 2026. openFDA masks brand and manufacturer names in these files, so drugs are counted by the active ingredients each record discloses and no figure is attributed to a brand, application or company. Ingredient names, and the separate reference lists of approved products, follow the FDA Green Book as of 1 Oct 2026. The month is the date FDA first received the report, not the date of the event. No report text, lot numbers or reporter details are published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.