Pet Drug Reports

Unclassifiable adverse event: in adverse event reports for animal drugs

Clinical sign, a VeDDRA term

In plain words: event that fits no dictionary term.

Read this first. FDA says this about the data:

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 publishes these words. Source: Adverse Event Reports for Animal Drugs and Devices, read on . The data have the reports that FDA received through .

This page is not veterinary advice. For an animal that is ill, speak to a veterinarian.

Contacting a veterinarianHow to report to FDA

From January 1987 to June 2026, FDA received 10,344 adverse event reports for animal drugs that list this sign. That is 0.8% of the 1,378,761 reports that FDA received from January 1987 to June 2026. In the 12 months to June 2026, FDA received 159 reports that list this sign.

Of the 10,344 reports, 85% are about people who were exposed to the drug. A report can list more than one sign and more than one drug. A report is not proof that a drug caused a sign.

By number of reports in all years, this sign is number 63 of 1,149 clinical signs with a page. Reports that list this sign fell by 0.6% in the 12 months to June 2026, compared with the 12 months before. Reports for all animal drugs fell by 4.6% in the same periods. The newest months can get more reports in a later update. Reports about people who were exposed to the drug are 85% of the reports that list this sign, and 1.2% of all reports.

Search engines list a sign page with 3,000 reports or more in all years. The page also needs 300 reports or more in the 12 months to June 2026. This page is under one of these numbers. The site keeps the page and keeps it out of search engines.

Drug pages with reports that list this sign

The table has every drug page with 20 or more reports that list this sign, in order of name. No count decides which drug is in the table. The table has 68 drug pages.

Show the 68 drug pages
Drug pages with 20 or more reports that list this sign, in order of name
Active ingredientsReports that list the sign
(S) - methoprene25
Afoxolaner27
Albendazole24
Altrenogest100
Amitraz102
Amoxicillin53
Bexagliflozin32
Buprenorphine70
Carprofen791
Cefovecin sodium24
Ceftiofur Hydrochloride25
Ceftiofur Sodium22
Clomipramine Hydrochloride183
Clorsulon + Ivermectin56
Copper Naphthenate21
Cyclosporine54
Deracoxib35
Detomidine Hydrochloride25
Dexamethasone + Thiabendazole114
Dexmedetomidine hydrochloride22
Dinoprost Tromethamine110
Doramectin231
Emodepside + Praziquantel26
Enrofloxacin126
Eprinomectin77
Epsiprantel43
Estradiol + Tylosin Tartrate21
Famphur103
Fenbendazole64
Firocoxib26
Florfenicol153
Flunixin Meglumine44
Fluralaner141
Gabapentin22
Grapiprant33
Imidacloprid + Moxidectin160
Insulin33
Isoflurane51
Ivermectin380
Ivermectin + Praziquantel36
Ivermectin + Pyrantel Pamoate57
Lotilaner34
Lubabegron35
Lufenuron + Milbemycin Oxime61
Maropitant71
Melarsomine Dihydrochloride47
Meloxicam113
Milbemycin Oxime136
Milbemycin Oxime + Praziquantel71
Milbemycin Oxime + Spinosad124
Monensin90
Moxidectin123
Nitenpyram47
Oclacitinib25
Oxibendazole43
Oxytetracycline40
Oxytetracycline Hydrochloride20
Pentobarbital96
Polysulfated Glycosaminoglycan24
Propofol25
Pyrantel Pamoate93
Selamectin1,596
Selegiline Hydrochloride45
Spinosad123
Tilmicosin Phosphate2,095
Tulathromycin137
Tylosin152
Tylosin Phosphate33

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand. A report can name more than one drug.

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.

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. Source: Adverse Event Reports for Animal Drugs and Devices

Ingredients, all combinations

The list has every active ingredient with 20 or more reports that list this sign, in order of name. It has 75 ingredients.

Show the 75 ingredients

Reports by species

The share is of the 10,344 reports that list this sign. The sign is in 51.8% of all reports about the species human exposure. The sign is in 0.1% of all reports about the species dog.

Reports by month and by year

Reports for each month, Jul 2021 to Jun 2026. The month is the month in which FDA received the report.

FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.

Reports that list Unclassifiable adverse event, by the year in which FDA received them
YearReports
202660
2025180
2024142
2023133
2022103
202177
202088
201972
201868
201750
201647
201516
201451
2013114
2012247
2011436
2010559
2009568
2008546
2007554
2006529
2005548
2004603
2003604
2002679
2001727
2000678
1999523
1998407
1997272
1996133
1995161
1994117
1993106
199280
199115
19906
198928
198814
19873

What these reports record

Outcome at the time of the report

  • Reports with this sign
  • All reports
  • Recovered/Normal1.6%162, All reports: 20.7%
  • Recovered with Sequela[recovered, with a lasting effect]0.1%13, All reports: 2.3%
  • Ongoing1.2%123, All reports: 17.4%
  • Died2.7%277, All reports: 4.9%
  • Euthanized0.7%68, All reports: 1.5%
  • Outcome Unknown6.6%683, All reports: 22.7%

An outcome in a report is not proof that the drug caused it. The person who sends the report gives the outcome. Each share is of the 10,344 reports that list this sign.

Age of the animal

  • Reports with this sign
  • All reports
  • Under 1 year1.5%156, All reports: 9.5%
  • 1 to 3 years5.3%552, All reports: 23.9%
  • 4 to 7 years2.5%258, All reports: 20.2%
  • 8 to 11 years2.2%231, All reports: 15.4%
  • 12 years and over50.6%5,230, All reports: 10.7%
  • Age not given37.9%3,917, All reports: 20.3%

The outcome is for the full report, not for this sign only.

Next in the A to Z list of signs

All clinical signs

Cite this page

Pet Drug Reports. Unclassifiable adverse event: adverse event reports for animal drugs. https://petdrugreports.com/reaction/unclassifiable-adverse-event/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of . Reports received through .

Where the data come from

The counts come from the openFDA Animal and Veterinary adverse event files, export of 30 Oct 2026. The files have the reports that the FDA Center for Veterinary Medicine received through 26 Jun 2026. The files mask brand and manufacturer names. The site counts a drug by the active ingredients that each record gives, and gives no count to a brand, an application or a company. Ingredient names and the lists of approved products follow the FDA Green Book of 2 Nov 2026. The site counts the different spellings of one VeDDRA term together.

The site does not publish report text, lot numbers or details of a reporter. FDA's record is the authority. See how the site counts reports, the data sources and the corrections page.

Questions about this sign

What does this term mean in a report?

In plain words: event that fits no dictionary term. It is a term from VeDDRA, the list of terms that FDA and drug companies use to code a report. The person who coded the report selected the term.

How does the count of the latest 12 months compare with the 12 months before?

FDA received 159 reports in the 12 months to June 2026. It received 160 reports in the 12 months before. FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.

How many of these reports have a serious flag?

Of the 1,084 reports that say if the event was serious, 40.5% have the serious flag. The person who sends a report sets the flag.

Does a drug in the table cause this sign?

The reports do not show that. A report can name more than one drug. FDA states this about the data.

When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event.

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. Source: Adverse Event Reports for Animal Drugs and Devices