9 CFR § 3.33 - Classification and separation.

---
identifier: "/us/cfr/t9/s3.33"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "9 CFR § 3.33 - Classification and separation."
title_number: 9
title_name: "Animals and Animal Products"
section_number: "3.33"
section_name: "Classification and separation."
chapter_name: "ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE"
subchapter_number: "A"
subchapter_name: "ANIMAL WELFARE"
part_number: "3"
part_name: "STANDARDS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "7 U.S.C. 2131-2159; 7 CFR 2.22, 2.80, and 371.7."
regulatory_source: "32 FR 3273, Feb. 24, 1967, unless otherwise noted."
cfr_part: "3"
---


# 3.33 Classification and separation.

Animals housed in the same primary enclosure shall be maintained in compatible groups, with the following additional restrictions:

(a) Except where harem breeding is practiced, preweanling guinea pigs shall not be housed in the same primary enclosure with adults other than their parents.

(b) Guinea pigs shall not be housed in the same primary enclosure with hamsters, nor shall guinea pigs or hamsters be housed in the same primary enclosure with any other species of animals.

(c) Guinea pigs or hamsters under quarantine or treatment for a communicable disease shall be separated from other guinea pigs or hamsters and other susceptible species of animals in such a manner as to minimize dissemination of such disease.