21 CFR 58.90
Animal care
21 CFR 58.90 is the regulation titled “Animal care” in 21 CFR Part 58, Good Laboratory Practice for Nonclinical Laboratory Studies. Since 2021, 4 FDA warning letters have cited it.
- Letters citing it
- 4 since 2021
- Jan 1 to Oct 30, 2026
- 0 against 2 on the same dates in 2025
- Most often cited with
- 21 CFR 58.202, in 4 letters
- Closed out
- 0% of these letters have a published close-out
Letters citing it, by year issued
All are medical device letters. 2026 runs to Oct 30, 2026. Pick a year to see its letters.
What FDA writes when it cites it
The finding headings that cite 21 CFR 58.90 most often, as written in the letters.
- 1 letterFailure of the testing facility to ensure that all newly received animals from outside sources were isolated and their health status evaluated in accordance with acceptable veterinary medical practice [21 CFR 58.90(b)]
- 1 letterFailure of the testing facility to ensure warm-blooded animals, excluding suckling rodents, used in laboratory procedures that require manipulations and observations over an extended period of time or in studies that…
- 1 letterFailure to ensure that warm-blooded animals shall receive appropriate identification where all information needed to specifically identify each animal within an animal-housing unit appears on the outside of that unit…
The regulation
Read the text of 21 CFR 58.90 (eCFR, as of Sep 1, 2026)
(a) There shall be standard operating procedures for the housing, feeding, handling, and care of animals.
(b) All newly received animals from outside sources shall be isolated and their health status shall be evaluated in accordance with acceptable veterinary medical practice.
(c) At the initiation of a nonclinical laboratory study, animals shall be free of any disease or condition that might interfere with the purpose or conduct of the study. If, during the course of the study, the animals contract such a disease or condition, the diseased animals shall be isolated, if necessary. These animals may be treated for disease or signs of disease provided that such treatment does not interfere with the study. The diagnosis, authorizations of treatment, description of treatment, and each date of treatment shall be documented and shall be retained.
(d) Warm-blooded animals, excluding suckling rodents, used in laboratory procedures that require manipulations and observations over an extended period of time or in studies that require the animals to be removed from and returned to their home cages for any reason (e.g., cage cleaning, treatment, etc.), shall receive appropriate identification. All information needed to specifically identify each animal within an animal-housing unit shall appear on the outside of that unit.
(e) Animals of different species shall be housed in separate rooms when necessary. Animals of the same species, but used in different studies, should not ordinarily be housed in the same room when inadvertent exposure to control or test articles or animal mixup could affect the outcome of either study. If such mixed housing is necessary, adequate differentiation by space and identification shall be made.
(f) Animal cages, racks and accessory equipment shall be cleaned and sanitized at appropriate intervals.
(g) Feed and water used for the animals shall be analyzed periodically to ensure that contaminants known to be capable of interfering with the study and reasonably expected to be present in such feed or water are not present at levels above those specified in the protocol. Documentation of such analyses shall be maintained as raw data.
(h) Bedding used in animal cages or pens shall not interfere with the purpose or conduct of the study and shall be changed as often as necessary to keep the animals dry and clean.
(i) If any pest control materials are used, the use shall be documented. Cleaning and pest control materials that interfere with the study shall not be used.
[43 FR 60013, Dec. 22, 1978, as amended at 52 FR 33780, Sept. 4, 1987; 54 FR 15924, Apr. 20, 1989; 56 FR 32088, July 15, 1991; 67 FR 9585, Mar. 4, 2002]
Text from eCFR as of Sep 1, 2026.
Cited alongside it
Regulations that appear in the same letters as 21 CFR 58.90.
- 21 CFR 58.202Grounds for disqualification4 letters cite both
- 21 CFR 58.33Study director4 letters cite both
- 21 CFR 58.35Quality assurance unit4 letters cite both
- 21 CFR 58.81Standard operating procedures3 letters cite both
- 21 CFR 58.130Conduct of a nonclinical laboratory study2 letters cite both
- 21 CFR 58.185Reporting of nonclinical laboratory study results2 letters cite both
- 21 CFR 58.31Testing facility management2 letters cite both
- 21 CFR 58.107Test and control article handling1 letter cites both
Latest letters citing it
The 3 letters citing 21 CFR 58.90 that FDA posted most recently.
- DevicesView Jiangsu Kerbio Medical Technology Group Co.nonclinical laboratory testing services for medical devicesIssuedJul 11, 2025PostedAug 26, 2025
- DevicesView CCIC Huatongwei International Inspection Co., Ltd.GLP nonclinical safety testing for medical devicesIssuedJun 25, 2025PostedAug 26, 2025
- DevicesView Mid-Link Testing Company, Ltdnonclinical laboratory studies for medical devicesIssuedSep 10, 2024PostedSep 11, 2024
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Counts include every citation in a letter, as the Letters filter does. How this database is built.