Pet Drug Reports

Drugs by active ingredient

Drug · single active ingredient

Mycophenolate: adverse event reports

All products with this active ingredient · not in an FDA-approved animal drug

95reports naming this ingredient, 2012–20260% of all reports · about 7 a year
19reports, 12 months to March 202618 in the 12 months before
78.5%classed serious, as reportedof 93 reports stating it
49.5%record death or euthanasia, as reported47 reports
96.8%of reports concern dogs0% of all dog reports

FDA has received 95 adverse event reports in which a drug is recorded with mycophenolate as its active ingredient, from December 2012 to February 2026. It is not the active ingredient of an FDA-approved animal drug; it reaches animals through human-label or compounded products.

openFDA masks the brand and manufacturer in every report, so these figures describe the ingredient across all products and cannot be attributed to a brand.

In the 12 months to March 2026, 19 reports named it, close to the 18 of the 12 months before. Recent months are provisional: fDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Over its whole reporting history that is about 7 reports a year and 0% of all 1,357,245 reports (0% of all dog reports). How many animals received it is not published, so a count says nothing about how often a problem occurs per dose.

Reporters most often listed lethargy (38.9%), death by euthanasia (34.7%) and immune mediated haemolytic anaemia (29.5%). A report can list several signs, so shares add to more than 100%; 384 different terms appear across these reports.

96.8% of reports concern dogs. Of reports that state seriousness, 78.5% were classed as serious, and 49.5% of all reports record a death or euthanasia as an outcome, as reported. FDA has not necessarily determined whether any drug played a part.

Monthly reports by species, five years

Dog49 · peak 5
Sep 2021: 2Nov 2021: 1Feb 2022: 1May 2022: 1Jul 2022: 1Apr 2023: 1Oct 2023: 1Nov 2023: 1Jan 2024: 1Feb 2024: 1Mar 2024: 1Apr 2024: 1May 2024: 2Jun 2024: 3Jul 2024: 1Oct 2024: 1Nov 2024: 1Dec 2024: 2Jan 2025: 3Feb 2025: 4Apr 2025: 1May 2025: 2Jun 2025: 1Jul 2025: 3Aug 2025: 2Sep 2025: 5Oct 2025: 1Nov 2025: 1Dec 2025: 1Feb 2026: 22022202320242025
Cat0 · peak 1
2022202320242025
Horse0 · peak 1
2022202320242025
Other1 · peak 1
Oct 2023: 12022202320242025

Reports by the month FDA received them. Each panel has its own scale; the peak month is printed at the top right. The newest months are incomplete because FDA posts reports with a delay of three to six months.

Reports by year received

012242012: 120122013: 220132014: 420142015: 520152016: 420162017: 820172018: 920182019: 720192020: 520202021: 320212022: 320222023: 420232024: 1420242025: 2420252026: 22026

2026 covers reports received through March 2026 only.

Signs listed in reports

share of mycophenolate reports listing the termall dog reports

  1. Lethargy[unusually tired or inactive]38.9%37
  2. Death by euthanasia[the animal was euthanized]34.7%33
  3. Immune mediated haemolytic anaemia[the immune system destroying red blood cells]29.5%28
  4. Vomiting25.3%24
  5. Leucocytosis NOS[high white blood cell count]24.2%23
  6. Thrombocytopenia[low platelet count]20%19
  7. Anaemia NOS[low red blood cell count]18.9%18
  8. Anorexia[not eating]18.9%18
  9. Diarrhoea[diarrhea]18.9%18
  10. Other abnormal test result NOS[abnormal laboratory result, type not specified]18.9%18
  11. Neutrophilia[high neutrophil count]16.8%16
  12. Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]13.7%13
  13. Elevated serum alkaline phosphatase (SAP)[a liver and bone enzyme above the normal range]13.7%13
  14. Elevated total bilirubin[bilirubin above the normal range]13.7%13
  15. Pale mucous membrane[pale gums]13.7%13
  16. Death12.6%12
  17. Fever12.6%12
  18. Not eating12.6%12
  19. Elevated blood urea nitrogen (BUN)[a kidney value above the normal range]11.6%11
  20. Hypoalbuminaemia[low blood albumin]9.5%9
  21. Icterus[jaundice (yellowing)]9.5%9
  22. Proteinuria[protein in the urine]9.5%9
  23. Ataxia[unsteady, uncoordinated movement]8.4%8
  24. Decreased packed cell volume (PCV)[lower share of red cells in the blood]8.4%8

Top 30 of 384 coded terms (VeDDRA, the veterinary reporting dictionary; plain-language gloss in brackets). One report can list several terms. The ticks show how often the same term appears in a wider pool of reports; they describe the reports, and FDA cautions that such figures cannot be used to estimate risk or to compare one product with another. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand.

Outcomes and report types

Outcome recorded in the report

Recovered/Normal4.2%4
Recovered with Sequela1.1%1
Ongoing27.4%26
Died12.6%12
Euthanized36.8%35
Outcome Unknown17.9%17

What kind of report it was

Safety issue90.5%86
Lack of expected effectiveness3.2%3
Both safety and lack of expected effectiveness5.3%5
Manufacturing or product defect1.1%1
Other0%0

Coloured bar: reports naming mycophenolate. Grey bar: all 1,357,245 reports in the database. Outcomes are the status at the time of the last report, as stated by the reporter; a report covering several animals can carry more than one outcome. FDA has not necessarily determined whether any drug played a part in any outcome.

Species and breeds in the reports

Species

Dog96.8%92
Human exposure2.1%2
Cat1.1%1

Single-breed animals

Breed shares follow how common each breed is. Crossbred animals and reports with no breed stay in the species figure only.

Age, weight and route

Age of the animal

Under 1 year4.2%4
1 to 3 years7.4%7
4 to 7 years44.2%42
8 to 11 years28.4%27
12 years and over12.6%12
Age not given3.2%3

Weight of the animal

Under 5 kg (11 lb)6.3%6
5 to 9.9 kg (11–22 lb)14.7%14
10 to 24.9 kg (22–55 lb)33.7%32
25 to 44.9 kg (55–99 lb)33.7%32
45 kg and over (99 lb+)8.4%8
Weight not given3.2%3

Route of administration stated in reports: oral (35), ophthalmic (1).

In context

MeasureMycophenolateAll dog reportsAll reports
Reports95985,6751,357,245
Share of that pool's reports naming this drug—0%0%
Classed serious, of reports stating it78.5%38.3%38.6%
Death or euthanasia recorded, per 1,000 reports494.75563.8
Filed as lack of expected effectiveness (wholly or partly)8.4%—23%
Top term, share of reportsLethargy 38.9%7.9%—

This set accounts for 100% of all reports naming mycophenolate, so no separate ingredient column is shown. Shares are of reports, not of animals treated. The number of doses sold is not public, so none of these figures is a rate of occurrence, and differences between columns reflect which animals receive a drug and who reports as much as anything else.

FDA-approved products (Green Book)

Reference information, not report statistics. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The list below is the FDA Green Book as of 1 Oct 2026; nothing on this page says which of these products, if any, a report concerned.

The Green Book lists no approved animal drug with these ingredients. Reports reach FDA for human-label and compounded drugs that veterinarians prescribe.

Species are the major species the Green Book search lists for the application ("—" where it lists another species or none). Approval dates are not part of the Green Book listing files and are not shown. Pioneer applications (NADA) come first, then generics (ANADA).

Questions about mycophenolate reports

How many adverse event reports has FDA received for mycophenolate?

95 reports record a drug with mycophenolate as its active ingredient in the openFDA release of 28 Sep 2026, covering reports received through March 2026. 19 of them arrived in the latest 12 months.

Which brand do these reports concern?

That cannot be known from the public data. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand.

What signs are reported most often?

lethargy (38.9%), death by euthanasia (34.7%), immune mediated haemolytic anaemia (29.5%), vomiting (25.3%) and leucocytosis NOS (24.2%). These are the coded terms listed in reports; several can appear in one report, and a term's presence is not a finding that the drug was responsible.

Which species and breeds appear in these reports?

dog (96.8%), human exposure (2.1%) and cat (1.1%). Among single-breed animals the most frequent labels are Labrador Retriever, Maltese, Australian Shepherd Dog and Boxer; popular breeds appear often in any drug's reports because there are more of them.

Are reports rising?

19 reports in the 12 months to March 2026, close to the 18 of the 12 months before. FDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Counts also move with sales, publicity and time on the market.

Do these reports show that mycophenolate harms pets?

Report counts cannot show that. FDA states that "there is no certainty that the reported drug or device caused the adverse event" and that the event "may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources." FDA also notes that commonly used products may have more reports simply because more animals receive them.

Are these the side effects of mycophenolate?

They are signs listed in reports, not an established list of side effects. The adverse reactions observed in studies are printed on each product's FDA-approved label, which a veterinarian can go through with you. This page is a record of what was reported to FDA.

How do I report a problem with an animal drug?

FDA asks owners and veterinarians to call the drug company first (the number is on the label); companies must pass reports to FDA. Reports can also go directly to FDA on Form FDA 1932a. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Animal & Veterinary adverse event bulk files released 28 Sep 2026, which hold reports FDA's Center for Veterinary Medicine received through 31 Mar 2026. openFDA masks brand and manufacturer names in these files, so drugs are counted by the active ingredients each record discloses and no figure is attributed to a brand, application or company. Ingredient names, and the separate reference lists of approved products, follow the FDA Green Book as of 1 Oct 2026. Drug entries are grouped by the active ingredients their unmasked ingredient field discloses; the application number that records also carry is not used. No report text, lot numbers or reporter details are published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.