Weakness: in adverse event reports for animal drugs

Clinical sign, a VeDDRA 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 2 Oct 2026. The data have the reports that FDA received through 26 Jun 2026.

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

Contacting a veterinarian How to report to FDA

From January 1987 to June 2026, FDA received 10,825 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 639 reports that list this sign.

Of the 10,825 reports, 82.2% are about dogs. 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 58 of 1,149 clinical signs with a page. Reports that list this sign fell by 11.5% 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 dogs are 82.2% of the reports that list this sign, and 72.6% of all reports.

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 120 drug pages.

Show the 120 drug pages

Drug pages with 20 or more reports that list this sign, in order of name
Active ingredients	Reports that list the sign
(S) - methoprene	66
Acepromazine Maleate	36
Afoxolaner	215
Afoxolaner + Moxidectin + Pyrantel Pamoate	37
Amantadine	30
Amitraz	30
Amlodipine	27
Amoxicillin	140
Amoxicillin + Clavulanate Potassium	46
Amoxicillin Trihydrate + Clavulanate Potassium	50
Ampicillin Sodium	22
Atipamezole Hydrochloride	56
Atropine	21
Bedinvetmab	747
Bexagliflozin	51
Buprenorphine	109
Butorphanol Tartrate	85
Capromorelin	86
Carprofen	1,466
Cefovecin sodium	313
Cefpodoxime proxetil	72
Cephalexin	55
Clindamycin	32
Clindamycin Hydrochloride	23
Cyclosporine	190
Deracoxib	355
Desoxycorticosterone Pivalate	96
Dexamethasone	137
Dexamethasone Sodium Phosphate	49
Dexmedetomidine	32
Dexmedetomidine hydrochloride	44
Dextrose	28
Diazepam	31
Diphenhydramine	173
Doramectin	31
Doxycycline	88
Emodepside + Praziquantel	42
Enalapril Maleate	38
Enrofloxacin	151
Eprinomectin + Esafoxolaner + Praziquantel	25
Estriol	26
Etodolac	35
Famotidine	120
Febantel + Praziquantel + Pyrantel Pamoate	36
Fenbendazole	93
Firocoxib	162
Florfenicol + Mometasone furoate + Terbinafine	32
Fluralaner	422
Frunevetmab	105
Furosemide	45
Gabapentin	334
Grapiprant	144
Hydromorphone	33
Ilunocitinib	24
Imidacloprid	41
Imidacloprid + Moxidectin	145
Insulin	219
Isoflurane	63
Ivermectin	288
Ivermectin + Praziquantel + Pyrantel Pamoate	56
Ivermectin + Pyrantel Pamoate	278
Ketamine Hydrochloride	64
Levetiracetam	21
Levothyroxine sodium	77
Lotilaner	71
Lufenuron	24
Lufenuron + Milbemycin Oxime	142
Marbofloxacin	41
Maropitant	517
Medetomidine	24
Melarsomine Dihydrochloride	319
Meloxicam	191
Methocarbamol	27
Methylprednisolone Acetate	38
Metoclopramide	27
Metronidazole	108
Midazolam	50
Milbemycin Oxime	201
Milbemycin Oxime + Praziquantel	165
Milbemycin Oxime + Spinosad	520
Mirtazapine	55
Monensin	79
Moxidectin	802
Nitenpyram	88
Oclacitinib	223
Omeprazole	46
Ondansetron	45
Orbifloxacin	23
Ormetoprim + Sulfadimethoxine	36
Oxibendazole	25
Phenobarbital	43
Pimobendan	93
Polysulfated Glycosaminoglycan	94
Praziquantel	24
Praziquantel + Pyrantel Pamoate	81
Prednisolone	68
Prednisolone + Trimeprazine Tartrate	33
Prednisone	247
Propofol	56
Pyrantel Pamoate	111
Pyrantel Pamoate + Sarolaner	154
Robenacoxib	57
Sarolaner	135
Sarolaner + Selamectin	25
Selamectin	362
Selegiline Hydrochloride	135
Spinosad	256
Sucralfate	60
Sulfadimethoxine	37
Tepoxalin	24
Tigilanol tiglate	23
Tilmicosin Phosphate	67
Toceranib Phosphate	38
Tramadol	107
Trazodone	49
Triamcinolone Acetonide	31
Trilostane	489
Ursodiol	29
Velagliflozin	26
Vitamin E	30

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 116 ingredients.

Show the 116 ingredients

Reports by species

Dog82.2%8,900
Cat12.2%1,324
Cattle1.9%202
Horse1.3%139
Human exposure1.1%116
Pig0.3%35

The share is of the 10,825 reports that list this sign. The sign is in 0.9% of all reports about the species dog. The sign is in 0.9% of all reports about the species cat.

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 Weakness, by the year in which FDA received them
Year	Reports
2026	296
2025	742
2024	605
2023	362
2022	267
2021	322
2020	346
2019	336
2018	396
2017	425
2016	439
2015	407
2014	455
2013	473
2012	517
2011	344
2010	308
2009	357
2008	302
2007	298
2006	316
2005	278
2004	365
2003	248
2002	241
2001	227
2000	332
1999	264
1998	184
1997	70
1996	45
1995	45
1994	28
1993	29
1992	26
1991	17
1990	23
1989	27
1988	33
1987	30

What these reports record

Outcome at the time of the report

Reports with this sign
All reports

Recovered/Normal13.3%1,441, All reports: 20.7%
Recovered with Sequela[recovered, with a lasting effect]1.4%152, All reports: 2.3%
Ongoing17.3%1,876, All reports: 17.4%
Died22.2%2,401, All reports: 4.9%
Euthanized9.2%1,000, All reports: 1.5%
Outcome Unknown11.2%1,215, 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 10,825 reports that list this sign.

Age of the animal

Reports with this sign
All reports

Under 1 year11.2%1,208, All reports: 9.5%
1 to 3 years14.9%1,613, All reports: 23.9%
4 to 7 years17.6%1,905, All reports: 20.2%
8 to 11 years25.6%2,773, All reports: 15.4%
12 years and over26.4%2,855, All reports: 10.7%
Age not given4.4%471, 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. Weakness: adverse event reports for animal drugs. https://petdrugreports.com/reaction/weakness/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of 30 Oct 2026. Reports received through 26 Jun 2026.

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?: 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 639 reports in the 12 months to June 2026. It received 722 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 6,242 reports that say if the event was serious, 71.9% 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