Trembling: 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 12,613 adverse event reports for animal drugs that list this sign. That is 0.9% of the 1,378,761 reports that FDA received from January 1987 to June 2026. In the 12 months to June 2026, FDA received 262 reports that list this sign.

Of the 12,613 reports, 85.8% 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 47 of 1,149 clinical signs with a page. Reports that list this sign fell by 13.0% 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 85.8% of the reports that list this sign, and 72.6% 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 88 drug pages.

Show the 88 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	193
Afoxolaner	388
Afoxolaner + Moxidectin + Pyrantel Pamoate	40
Amoxicillin	81
Amoxicillin Trihydrate + Clavulanate Potassium	24
Atipamezole Hydrochloride	85
Bedinvetmab	107
Buprenorphine	27
Butorphanol Tartrate	76
Carprofen	548
Cefovecin sodium	107
Cefpodoxime proxetil	59
Cephalexin	33
Clomipramine Hydrochloride	71
Cyclosporine	393
Deracoxib	205
Desoxycorticosterone Pivalate	64
Detomidine Hydrochloride	25
Dexamethasone	30
Dexmedetomidine hydrochloride	55
Dichlorophene + Toluene	20
Diphenhydramine	56
Doxycycline	30
Emodepside + Praziquantel	86
Enalapril Maleate	33
Enrofloxacin	71
Famotidine	39
Febantel + Praziquantel + Pyrantel Pamoate	36
Fenbendazole	76
Fenthion	22
Firocoxib	81
Florfenicol + Mometasone furoate + Terbinafine	21
Flunixin Meglumine	20
Fluoxetine hydrochloride	101
Fluralaner	404
Furosemide	28
Gabapentin	91
Grapiprant	39
Imidacloprid	33
Imidacloprid + Moxidectin	368
Insulin	64
Isoflurane	24
Ivermectin	651
Ivermectin + Praziquantel	52
Ivermectin + Praziquantel + Pyrantel Pamoate	105
Ivermectin + Pyrantel Pamoate	604
Ketamine Hydrochloride	61
Ketoconazole	31
Levothyroxine sodium	29
Lotilaner	76
Lotilaner + Moxidectin + Praziquantel + Pyrantel Pamoate	22
Lufenuron	38
Lufenuron + Milbemycin Oxime	245
Lufenuron + Milbemycin Oxime + Praziquantel	22
Marbofloxacin	42
Maropitant	239
Medetomidine	43
Melarsomine Dihydrochloride	227
Meloxicam	124
Metronidazole	37
Milbemycin Oxime	462
Milbemycin Oxime + Praziquantel	107
Milbemycin Oxime + Spinosad	1,655
Moxidectin	436
Moxidectin + Praziquantel	25
Nitenpyram	261
Oclacitinib	146
Ormetoprim + Sulfadimethoxine	61
Pimobendan	81
Polysulfated Glycosaminoglycan	32
Praziquantel + Pyrantel Pamoate	70
Prednisolone	28
Prednisolone + Trimeprazine Tartrate	40
Prednisone	107
Propofol	51
Pyrantel Pamoate	79
Pyrantel Pamoate + Sarolaner	234
Sarolaner	207
Sarolaner + Selamectin	23
Selamectin	922
Selegiline Hydrochloride	99
Spinosad	1,234
Tiletamine Hydrochloride + Zolazepam Hydrochloride	59
Tilmicosin Phosphate	29
Tramadol	31
Trazodone	22
Trilostane	172
Vitamin E	29

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 85 ingredients.

Show the 85 ingredients

Reports by species

Dog85.8%10,826
Cat10%1,267
Horse1.8%221
Cattle1.1%133
Pig0.4%47
Human exposure0.4%46

The share is of the 12,613 reports that list this sign. The sign is in 1.1% of all reports about the species dog. The sign is in 0.8% 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 Trembling, by the year in which FDA received them
Year	Reports
2026	128
2025	283
2024	297
2023	236
2022	220
2021	268
2020	334
2019	338
2018	359
2017	375
2016	364
2015	447
2014	570
2013	612
2012	749
2011	868
2010	891
2009	816
2008	648
2007	501
2006	415
2005	413
2004	416
2003	325
2002	294
2001	357
2000	362
1999	195
1998	137
1997	74
1996	68
1995	46
1994	37
1993	23
1992	24
1991	21
1990	19
1989	31
1988	22
1987	30

What these reports record

Outcome at the time of the report

Reports with this sign
All reports

Recovered/Normal18.3%2,314, All reports: 20.7%
Recovered with Sequela[recovered, with a lasting effect]2%257, All reports: 2.3%
Ongoing9.4%1,186, All reports: 17.4%
Died8.5%1,068, All reports: 4.9%
Euthanized1.6%198, All reports: 1.5%
Outcome Unknown11.4%1,442, 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 12,613 reports that list this sign.

Age of the animal

Reports with this sign
All reports

Under 1 year16.7%2,108, All reports: 9.5%
1 to 3 years27.7%3,496, All reports: 23.9%
4 to 7 years21.8%2,754, All reports: 20.2%
8 to 11 years16.9%2,137, All reports: 15.4%
12 years and over11.7%1,479, All reports: 10.7%
Age not given5.1%639, 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

Tooth disorder
Torn ligament
Toxicity
Trauma NOS[NOS: not otherwise specified]
Tremor
Tremor of limb
Tubes, Abnormal[a product quality report, not a sign in an animal]
Tubes, Damaged[a product quality report, not a sign in an animal]

All clinical signs

Cite this page

Pet Drug Reports. Trembling: adverse event reports for animal drugs. https://petdrugreports.com/reaction/trembling/ 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 262 reports in the 12 months to June 2026. It received 301 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 5,431 reports that say if the event was serious, 44.6% 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