Pet Drug Reports

How the site counts reports

Last checked against the FDA pages:

Every figure is a count of records in the openFDA animal and veterinary adverse event files. The export used is of . The site does not model or estimate any figure.

What the site counts

One record in the files is one report. The site counts each record one time. The data have 1,378,761 reports, received through .

A record has the drugs that the animal got, the clinical signs, the species, breed, age and weight, the outcome and the kind of report. The site counts these coded fields.

The site does not keep text of reports, lot numbers or details of a reporter.

93 records have no usable date of receipt. The site leaves them out.

Counting by active ingredient

The openFDA records mask the brand name of each drug. The site cannot count a report for a brand. It counts by active ingredient.

  • A drug page covers one set of active ingredients. The set can be one ingredient or a combination of up to 6.
  • A page for all combinations counts one ingredient alone and in every combination.
  • The site makes a page for all combinations only when no single set holds 90% or more of the reports of the ingredient. 248 ingredients have a drug page only.

The ingredient field of a record is not tidy. The site reads it as follows.

  • It looks for the ingredient names of the Green Book, longest name first.
  • It also looks for a short list of substances that veterinarians prescribe from human labels.
  • It ignores everything else, for example brand names, vaccines and descriptions that a reporter typed.
  • A drug with no name that the site recognises is not counted for any drug page.

The Green Book file of 2 Nov 2026 has 2,432 applications.

Counting rules

  • A report that names three drugs counts one time for each set of active ingredients, and one time for each active ingredient.
  • A report that lists five signs counts one time for each sign. The shares of signs can add to more than 100%.
  • A report counts for the month in which FDA received it. This month is not the month of the event.
  • The serious flag is the mark that the reporter set. The site shows its share among the reports that say if the event was serious.
  • The outcome words are the words of FDA, for example "Died" and "Euthanized". A report about more than one animal can have more than one outcome.
  • A breed page counts the reports that give one breed. Reports about crossbred animals are in the species count only.
  • The site converts ages given in days, weeks or months to years.
  • Spellings of one VeDDRA term are counted together. Older FDA terms are shown in small letters and marked as terms of older reports.

Pages and table rows

A page is made only when the count is high enough. A page that is made stays on the site and keeps its address.

  • Drug pages: 20 or more reports. The table of drugs has the pages with 50 reports or more.
  • Pages for all combinations: 50 or more reports.
  • Species pages: 100 or more reports. Breed pages: 100 or more reports.
  • Clinical sign pages: 200 or more reports.
  • Month pages: 300 or more reports.

Which pages search engines list

Search engines list only the pages with enough reports of their own. A page under a number stays on the site. It says that search engines do not list it, and its list links it.

  • Drug pages: 500 reports or more in all years, and 30 reports or more in the 12 months to 26 Jun 2026.
  • Pages for all combinations: 500 reports or more in all years, and 30 or more in the latest 12 months.
  • Clinical sign pages: 3,000 reports or more in all years, and 300 or more in the latest 12 months.
  • Breed pages: 1,500 reports or more in all years, and 30 or more in the latest 12 months.
  • Species pages, the lists, the findings, the guides and the pages about the site are listed. Month pages and the pages of the brand name letters are not listed.

The numbers keep the search index to pages that have figures of their own. They do not rate a drug, a sign or a breed.

A table of drugs on a species, breed, sign or month page has every drug page with a minimum number of reports for that page. The minimum is 20 for a species, 5 for a breed, 20 for a sign and 10 for a month.

These tables are in order of name, and no count decides which drug is in a table. No page ranks drugs. A sign or breed page states its position by the number of reports in all years. A finding can order signs or species by number of reports. A position is a count of activity. It is not a measure of risk and it does not compare drugs.

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.

FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices

Shares, trends and glosses

A share is a part of the reports of the page. It is not a rate, because the files do not give the number of animals that got a drug.

The trend compares the latest 12 months with the 12 months before. A chart shows the month in which FDA received the report. The newest months can get more reports in a later update.

A VeDDRA term is shown as FDA codes it. A plain gloss in brackets explains the word. The gloss comes from a fixed list that the site keeps. A term with no entry has no gloss.

The Green Book lists on a drug page are reference data. They have no count, and the site does not link an entry of the Green Book to a report.

Editorial policy

  • The site states a count, its period and its source. It does not say that a drug caused a sign.
  • The site uses the terms of FDA. It defines each term one time, in the glossary.
  • The site does not rank, compare or grade drugs. It does not rate a drug. It orders signs and species by the number of reports only, and says so beside each order.
  • The site gives no advice about the care of an animal.
  • A fixed sentence in a program writes each sentence about a count. No generative AI runs when the site is built.
  • An AI writing tool drafted the guides and the pages about the site. The publisher is responsible for them. The page shows the date of its last check against FDA pages.
  • Each sentence of FDA is a quotation, with the page that it comes from and the date on which the site read the page.
  • The site changes a page when it finds an error. Corrections shows the log.

Known gaps

Brand names are masked

The site cannot say which brand a report is about. Two products with the same active ingredient are in one count.

Two reports can describe one event

The site does not check if two reports describe the same event. If the files hold two such reports, the site counts both.

The number of reports changes over time

FDA gives this reason for the rise in the total number of reports.

Increases in the total number of AERs is likely a result of improved reporting; however, the FDA believes that AERs are still underreported.

FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices

The site gives no other reason for a rise or a fall of a count.

FDA posts reports after a delay

Reports are not posted in real time. Updates to openFDA are made quarterly, but there may be a 3-6 month delay from the time FDA receives reports until they are posted.

FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices

The files have no number of animals treated

The site cannot show how often an event happens for each animal that got a drug.

The files have more than approved drugs

The AER data received by CVM and uploaded to openFDA.gov includes reports associated with approved animal drugs, unapproved/compounded drugs and devices used in animals.

FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices

The ingredient field can be incomplete

A record for a drug with three ingredients can name two. The site then counts the report for the set of two.

Reporters choose the codes

The person who codes a report selects the clinical sign, the outcome and the serious flag. The site shows them as given.