Clinical signs in the most reports, 12 months to June 2026
Finding from the reports that FDA received through 26 Jun 2026
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 .
The sign "Vomiting" is in the largest number of the reports that FDA received in the 12 months to June 2026: 7,871 of 74,895 reports (10.5%).
Of the 25 signs in the table, 6 were listed in more reports than in the 12 months before.
19 were listed in the same number of reports or fewer.
A report can list more than one sign, so the shares in the table add up to more than 100%.
The 25 signs with the most reports
| Position | Sign | In plain words | Reports, 12 months to June 2026 | Reports, 12 months before | Change | Share of the 74,895 reports |
|---|---|---|---|---|---|---|
| 1 | Vomiting | 7,871 | 8,585 | -8.3% | 10.5% | |
| 2 | Lack of efficacy (ectoparasite) - flea | the product did not have the expected effect: fleas | 6,828 | 5,092 | +34.1% | 9.1% |
| 3 | Lethargy | unusually tired or inactive | 5,732 | 6,302 | -9.0% | 7.7% |
| 4 | Lack of efficacy (endoparasite) - heartworm | the product did not have the expected effect: heartworm | 5,433 | 5,729 | -5.2% | 7.3% |
| 5 | Diarrhoea | diarrhea | 4,531 | 4,650 | -2.6% | 6% |
| 6 | Lack of efficacy - NOS | the product did not have the expected effect | 4,330 | 4,441 | -2.5% | 5.8% |
| 7 | Lack of efficacy (endoparasite) - hookworm | the product did not have the expected effect: hookworms | 4,195 | 3,814 | +10.0% | 5.6% |
| 8 | Medication error NOS | a mistake in giving the product, type not specified | 3,250 | 2,396 | +35.6% | 4.3% |
| 9 | Lack of efficacy (bacteria) - Borrelia | the product did not have the expected effect: Borrelia (Lyme disease bacteria) | 2,791 | 3,147 | -11.3% | 3.7% |
| 10 | Seizure NOS | seizure, type not specified | 2,784 | 3,284 | -15.2% | 3.7% |
| 11 | Intentional misuse | use that was knowingly different from the label | 2,412 | 2,538 | -5.0% | 3.2% |
| 12 | Not eating | 2,375 | 2,673 | -11.1% | 3.2% | |
| 13 | Emesis (multiple) | vomiting more than once | 2,109 | 1,786 | +18.1% | 2.8% |
| 14 | Weight loss | 2,042 | 2,155 | -5.2% | 2.7% | |
| 15 | Death | 2,015 | 2,518 | -20.0% | 2.7% | |
| 16 | Lack of efficacy (bacteria) - Anaplasma | the product did not have the expected effect: Anaplasma bacteria | 1,994 | 1,453 | +37.2% | 2.7% |
| 17 | Lack of efficacy (ectoparasite) - tick NOS | the product did not have the expected effect: ticks | 1,968 | 1,538 | +28.0% | 2.6% |
| 18 | Lack of efficacy (endoparasite) - roundworm NOS | the product did not have the expected effect: roundworms | 1,864 | 2,109 | -11.6% | 2.5% |
| 19 | Death by euthanasia | the animal was euthanized | 1,829 | 2,782 | -34.3% | 2.4% |
| 20 | Decreased appetite | 1,586 | 1,737 | -8.7% | 2.1% | |
| 21 | Behavioural disorder NOS | behaviour change, type not specified | 1,526 | 1,645 | -7.2% | 2% |
| 22 | Ataxia | unsteady, uncoordinated movement | 1,409 | 1,799 | -21.7% | 1.9% |
| 23 | Lack of efficacy (endoparasite) - tapeworm | the product did not have the expected effect: tapeworms | 1,279 | 1,303 | -1.8% | 1.7% |
| 24 | Elevated alanine aminotransferase (ALT) | a liver enzyme above the normal range | 1,264 | 1,324 | -4.5% | 1.7% |
| 25 | Other abnormal test result NOS | abnormal laboratory result, type not specified | 1,195 | 1,196 | -0.1% | 1.6% |
In earlier editions
- October 2026: the first row was Vomiting (7,871).
How the figures were made
The order is the number of reports that list the sign. A sign in a report is a term coded by the person who sent the report. A report is not proof that a drug caused a sign.
Some terms are about a product that did not have the expected effect, or about a defect of a package. The terms are from VeDDRA and from older FDA reports.
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.
A program makes this page from the openFDA files with fixed sentence rules. How the site counts reports. Sources and licences.
Cite this page
Pet Drug Reports. Clinical signs in the most reports, 12 months to June 2026. https://petdrugreports.com/findings/signs-in-the-most-reports/ 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 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.