Monocytosis: in adverse event reports for animal drugs

Clinical sign, a VeDDRA term

In plain words: high monocyte count.

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 3,394 adverse event reports for animal drugs that list this sign. That is 0.3% of the 1,378,761 reports that FDA received from January 1987 to June 2026. In the 12 months to June 2026, FDA received 487 reports that list this sign.

Of the 3,394 reports, 84.3% 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 185 of 1,149 clinical signs with a page. Reports that list this sign rose by 36.8% 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 84.3% 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 87 drug pages.

Show the 87 drug pages

Drug pages with 20 or more reports that list this sign, in order of name
Active ingredients	Reports that list the sign
Acepromazine Maleate	30
Afoxolaner	205
Afoxolaner + Moxidectin + Pyrantel Pamoate	37
Amoxicillin	57
Amoxicillin + Clavulanate Potassium	40
Amoxicillin Trihydrate + Clavulanate Potassium	54
Ampicillin Sodium	27
Atipamezole Hydrochloride	29
Atropine	20
Bedinvetmab	180
Bexagliflozin	30
Buprenorphine	102
Butorphanol Tartrate	79
Capromorelin	63
Carprofen	475
Cefovecin sodium	137
Cefpodoxime proxetil	46
Cephalexin	30
Clindamycin	22
Cyclosporine	97
Deracoxib	134
Dexamethasone	82
Dexamethasone Sodium Phosphate	39
Dexmedetomidine	37
Dexmedetomidine hydrochloride	24
Dextrose	25
Diazepam	21
Diphenhydramine	87
Doxycycline	106
Enrofloxacin	109
Eprinomectin + Esafoxolaner + Praziquantel	32
Famotidine	87
Febantel + Praziquantel + Pyrantel Pamoate	21
Firocoxib	81
Florfenicol + Mometasone furoate + Terbinafine	22
Fluralaner	292
Frunevetmab	53
Furosemide	29
Gabapentin	187
Grapiprant	57
Hydromorphone	34
Ilunocitinib	35
Imidacloprid + Moxidectin	27
Insulin	48
Isoflurane	59
Ivermectin	36
Ivermectin + Pyrantel Pamoate	185
Ketamine Hydrochloride	30
Ketoconazole	24
Levothyroxine sodium	26
Lotilaner	59
Lufenuron + Milbemycin Oxime	46
Maropitant	388
Melarsomine Dihydrochloride	83
Meloxicam	127
Methadone	20
Methylprednisolone Acetate	26
Metoclopramide	36
Metronidazole	99
Midazolam	39
Milbemycin Oxime	31
Milbemycin Oxime + Praziquantel	76
Milbemycin Oxime + Spinosad	96
Mirtazapine	37
Moxidectin	177
Oclacitinib	135
Omeprazole	51
Ondansetron	66
Pimobendan	38
Polysulfated Glycosaminoglycan	28
Prednisolone	61
Prednisone	156
Propofol	57
Pyrantel Pamoate	28
Pyrantel Pamoate + Sarolaner	88
Rabacfosadine	28
Robenacoxib	41
Sarolaner	32
Selamectin	70
Spinosad	59
Sucralfate	54
Tigilanol tiglate	42
Tramadol	45
Trazodone	41
Trilostane	83
Velagliflozin	66
Verdinexor	20

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 87 ingredients.

Show the 87 ingredients

Reports by species

Dog84.3%2,860
Cat15%509
Horse0.6%20
Cattle0.1%4
Goatunder 0.1%1

The share is of the 3,394 reports that list this sign. The sign is in 0.3% of all reports about the species dog. The sign is in 0.3% 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 Monocytosis, by the year in which FDA received them
Year	Reports
2026	241
2025	423
2024	334
2023	193
2022	129
2021	131
2020	138
2019	162
2018	178
2017	198
2016	178
2015	101
2014	82
2013	67
2012	105
2011	79
2010	67
2009	77
2008	64
2007	117
2006	68
2005	64
2004	81
2003	27
2002	12
2001	13
2000	17
1999	19
1998	11
1997	2
1996	3
1995	3
1994	1
1992	2
1989	2
1988	2
1987	3

What these reports record

Outcome at the time of the report

Reports with this sign
All reports

Recovered/Normal7.1%241, All reports: 20.7%
Recovered with Sequela[recovered, with a lasting effect]1.4%49, All reports: 2.3%
Ongoing30.1%1,023, All reports: 17.4%
Died15.8%535, All reports: 4.9%
Euthanized14.4%490, All reports: 1.5%
Outcome Unknown17.3%586, 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 3,394 reports that list this sign.

Age of the animal

Reports with this sign
All reports

Under 1 year12.1%410, All reports: 9.5%
1 to 3 years17.5%595, All reports: 23.9%
4 to 7 years22.9%777, All reports: 20.2%
8 to 11 years28.9%982, All reports: 15.4%
12 years and over17.8%604, All reports: 10.7%
Age not given0.8%26, 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. Monocytosis: adverse event reports for animal drugs. https://petdrugreports.com/reaction/monocytosis/ 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?: In plain words: high monocyte count. 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 487 reports in the 12 months to June 2026. It received 356 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 2,611 reports that say if the event was serious, 79.2% 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