Pet Drug Reports

Famotidineadverse event reports that FDA received

Active ingredient

The Green Book lists no brand name for exactly this active ingredient.

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.

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 .

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

Contacting a veterinarianHow to report to FDA

From November 2006 to June 2026, FDA received 3,067 adverse event reports that name a drug with famotidine as its active ingredient. Of the 3,067 reports, 2,643 (86.2%) are about dogs. 406 reports are about cats (13.2%).

In January to March 2026, FDA received 56 reports that name this drug. The signs that appear in the largest number of the 3,067 reports are "Vomiting", "Lethargy" and "Diarrhoea". A report is not proof that a drug caused a sign.

Reports that name this drug fell by 12.0% 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 86.2% of the reports that name this drug, and 72.6% of all reports.

Since the last update of the FDA data

The site recorded an update of the FDA data on . FDA changed these counts for January to March 2026:

  • All species: from 42 to 56.
  • Dog: from 38 to 49.

January to March 2026 is the latest closed quarter in the data. In that quarter FDA received 56 reports that name famotidine: 49 dog, 7 cat, 0 horse, 0 other or not given.

All updatesFeed of updates (RSS)

Signs that the reports list

A sign is a coded term from the report. The words in brackets are a plain gloss of the term. The percentage is the share of the 3,067 reports that list the sign. One report can list more than one sign.

The sign that is in the largest number of the reports comes first.

  1. Vomiting29.1%894 reports
  2. Lethargy[unusually tired or inactive]27.5%842 reports
  3. Diarrhoea[diarrhea]17.2%529 reports
  4. Anorexia[not eating]16.1%494 reports
  5. Death by euthanasia[the animal was euthanized]14.1%431 reports
  6. Other abnormal test result NOS[abnormal laboratory result, type not specified]13.1%402 reports
  7. Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]11.6%357 reports
  8. Weight loss9.4%289 reports
  9. Not eating9.4%288 reports
  10. Death9.3%286 reports
  11. Decreased appetite9.3%286 reports
  12. Elevated serum alkaline phosphatase (SAP)[a liver and bone enzyme above the normal range]8.5%262 reports
  13. Elevated blood urea nitrogen (BUN)[a kidney value above the normal range]7.9%242 reports
  14. Anaemia NOS[low red blood cell count]7.4%227 reports
Show the next 16 signs
  1. Emesis[vomiting]7.3%225 reports
  2. Elevated total bilirubin[bilirubin above the normal range]7.3%224 reports
  3. Lack of efficacy - NOS[the product did not have the expected effect]7.3%223 reports
  4. Abnormal radiograph finding6.8%210 reports
  5. Dehydration6.8%208 reports
  6. Leucocytosis NOS[high white blood cell count]6.7%207 reports
  7. Abnormal ultrasound finding6.6%202 reports
  8. Elevated creatinine[a kidney value above the normal range]6.2%190 reports
  9. Elevated liver enzymes[liver enzymes above the normal range]5.7%176 reports
  10. Fever5.3%164 reports
  11. Neutrophilia[high neutrophil count]5.3%164 reports
  12. Pain NOS[NOS: not otherwise specified]5.2%160 reports
  13. Behavioural disorder NOS[behaviour change, type not specified]5.1%156 reports
  14. Bloody diarrhoea[diarrhea with blood]5%154 reports
  15. Panting4.8%148 reports
  16. Hypoalbuminaemia[low blood albumin]4.7%145 reports

The list shows 30 of 1,554 coded signs. A report is not proof that a drug caused a sign. Download all signs (CSV)

Reports by species

  • Dog86.2%2,643
  • Cat13.2%406
  • Human exposure0.3%9
  • Goat0.1%2
  • Parrot0.1%2
  • Ferretunder 0.1%1

The share is of all 3,067 reports that name famotidine. The other reports give a different species or no species.

Reports for each month, Jul 2021 to Jun 2026

Dog953 reports. Largest count in one month: 28 (Sep 2024)
Cat170 reports. Largest count in one month: 10 (Nov 2025)
Horse1 report

No chart: no month has 5 or more reports.

Other or not given6 reports

No chart: no month has 5 or more reports.

The month is the month in which FDA received the report. Each chart has its own scale. 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 by year

  • Dog
  • Cat
  • Horse
  • Other or not given
Reports that name famotidine, by the year in which FDA received them and by species
YearDogCatHorseOther or not givenAll species
20261081010119
20252435004297
20242314301275
20232034101245
20221181800136
20211071207126
20201032401128
20191142700141
20181672303193
20172182600244
20162652000285
20151532600179
20141261200138
20132644200306
20122043100235
20111500015
200901001
200810001
200710001
200620002

2026 has the reports that FDA received through Jun 2026. Download the years (CSV)

What the reports record

Outcome at the time of the report

  • Recovered/Normal22%676
  • Recovered with Sequela[recovered, with a lasting effect]1.1%33
  • Ongoing33.7%1,035
  • Died9.9%305
  • Euthanized14.2%435
  • Outcome Unknown19.2%589

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 3,067 reports that name famotidine.

A report about more than one animal can have more than one outcome.

Kind of report

  • Safety issue86.5%2,652
  • Lack of expected effectiveness2.4%75
  • Both safety and lack of expected effectiveness9.7%298
  • Manufacturing or product defect1.2%37
  • Other0.2%5

3,053 reports say if the event was serious. 55.2% of them have the serious flag. The person who sends the report sets the flag.

Show age, weight, breed and route

Age of the animal

  • Under 1 year5.5%169
  • 1 to 3 years15.3%468
  • 4 to 7 years24.1%738
  • 8 to 11 years30.8%946
  • 12 years and over22.9%702
  • Age not given1.4%44

Weight of the animal

  • Under 5 kg (11 lb)19.4%595
  • 5 to 9.9 kg (11 to 22 lb)22.8%698
  • 10 to 24.9 kg (22 to 55 lb)23.3%714
  • 25 to 44.9 kg (55 to 99 lb)27.6%847
  • 45 kg and over (99 lb and over)4.2%129
  • Weight not given2.7%84

Breed, where the report gives one breed

A breed with many animals has many reports.

Route in the report

  • Oral32.7%1,004
  • Subcutaneous4.9%151
  • Intravenous3.6%111
  • Parenteral0.9%29
  • Intramuscular0.2%6
  • Other0.2%5

Each bar is on a scale of 0 to 100%.

Approved animal drugs with this active ingredient (FDA Green Book)

This section is reference data. It has no report count.

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.

The Green Book lists no approved animal drug with this active ingredient. FDA also receives reports for human drugs and compounded drugs that veterinarians prescribe.

Next in the A to Z list

All drugs by active ingredient. Brand names A to Z

FDA pages for this drug

The site checked these addresses on . The links open in a new tab.

Cite this page

Pet Drug Reports. Famotidine: adverse event reports that FDA received. https://petdrugreports.com/drug/famotidine/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of . Reports received through .

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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 use the application number that a record has.

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 these reports

Which brand are these reports about?

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. The Green Book lists no brand name for exactly this active ingredient.

Do the reports show that the drug caused the signs?

No. 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

How many reports did FDA receive in the latest 12 months?

FDA received 272 reports in the 12 months to June 2026. It received 309 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.

What kinds of report are in the count?

Of the 3,067 reports received from November 2006 to June 2026, 86.5% are about a safety issue only. 12.2% are about a lack of expected effectiveness, alone or with a safety issue. 1.2% are about a defect of the product or its package.