Head tremor: 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.

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From September 2005 to June 2026, FDA received 2,532 adverse event reports for animal drugs that list this sign. That is 0.2% of the 1,378,761 reports that FDA received from January 1987 to June 2026. In the 12 months to June 2026, FDA received 183 reports that list this sign.

Of the 2,532 reports, 86.1% 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 231 of 1,149 clinical signs with a page. Reports that list this sign fell by 24.1% 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 86.1% 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 34 drug pages.

Show the 34 drug pages

Drug pages with 20 or more reports that list this sign, in order of name
Active ingredients	Reports that list the sign
Afoxolaner	332
Afoxolaner + Moxidectin + Pyrantel Pamoate	53
Bedinvetmab	91
Buprenorphine	25
Butorphanol Tartrate	21
Carprofen	48
Cefovecin sodium	32
Dexamethasone	21
Emodepside + Praziquantel	23
Enrofloxacin	20
Eprinomectin + Esafoxolaner + Praziquantel	32
Florfenicol + Mometasone furoate + Terbinafine	22
Fluralaner	289
Frunevetmab	31
Gabapentin	76
Imidacloprid + Moxidectin	58
Ivermectin	49
Ivermectin + Pyrantel Pamoate	187
Lotilaner	76
Lotilaner + Moxidectin + Praziquantel + Pyrantel Pamoate	20
Lufenuron + Milbemycin Oxime	41
Maropitant	66
Melarsomine Dihydrochloride	51
Milbemycin Oxime	29
Milbemycin Oxime + Praziquantel	85
Milbemycin Oxime + Spinosad	205
Moxidectin	66
Oclacitinib	78
Prednisone	53
Pyrantel Pamoate + Sarolaner	344
Sarolaner	269
Sarolaner + Selamectin	41
Selamectin	56
Spinosad	45

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 34 ingredients.

Show the 34 ingredients

Reports by species

Dog86.1%2,181
Cat13%330
Horse0.3%8
Cattle0.2%5
Pig0.1%3
Donkeyunder 0.1%1

The share is of the 2,532 reports that list this sign. The sign is in 0.2% of all reports about the species dog. The sign is in 0.2% 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 Head tremor, by the year in which FDA received them
Year	Reports
2026	90
2025	225
2024	263
2023	217
2022	204
2021	241
2020	262
2019	220
2018	218
2017	135
2016	98
2015	101
2014	84
2013	70
2012	65
2011	29
2010	1
2009	2
2008	5
2005	2

What these reports record

Outcome at the time of the report

Reports with this sign
All reports

Recovered/Normal36.4%922, All reports: 20.7%
Recovered with Sequela[recovered, with a lasting effect]1.6%41, All reports: 2.3%
Ongoing32%810, All reports: 17.4%
Died1.9%47, All reports: 4.9%
Euthanized4%101, All reports: 1.5%
Outcome Unknown24.4%618, 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 2,532 reports that list this sign.

Age of the animal

Reports with this sign
All reports

Under 1 year21.1%535, All reports: 9.5%
1 to 3 years32.8%830, All reports: 23.9%
4 to 7 years16.9%427, All reports: 20.2%
8 to 11 years13.2%334, All reports: 15.4%
12 years and over13.5%342, All reports: 10.7%
Age not given2.5%64, 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. Head tremor: adverse event reports for animal drugs. https://petdrugreports.com/reaction/head-tremor/ 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 183 reports in the 12 months to June 2026. It received 241 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 2,512 reports that say if the event was serious, 46.9% 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