#### § 3.53 Primary enclosures.

All primary enclosures for rabbits shall conform to the following requirements:

(a) *General.*

(1) Primary enclosures shall be structurally sound and maintained in good repair to protect the rabbits from injury, to contain them, and to keep predators out.

(2) Primary enclosures shall be constructed and maintained so as to enable the rabbits to remain dry and clean.

(3) Primary enclosures shall be constructed and maintained so that the rabbits contained therein have convenient access to clean food and water as required in this subpart.

(4) The floors of the primary enclosures shall be constructed so as to protect the rabbits' feet and legs from injury. Litter shall be provided in all primary enclosures having solid floors.

(5) A suitable nest box containing clean nesting material shall be provided in each primary enclosure housing a female with a litter less than one month of age.

(b) *Space requirements for primary enclosures acquired before August 15, 1990.* Primary enclosures shall be constructed and maintained so as to provide sufficient space for the animal to make normal postural adjustments with adequate freedom of movement. Each rabbit housed in a primary enclosure shall be provided a minimum amount of floor space, exclusive of the space taken up by food and water receptacles, in accordance with the following table:

| Category | Individual weights (pounds) | Minimum space per rabbit (square inches) |
| --- | --- | --- |
| Groups | 3 through 5 | 144 |
| | 6 through 8 | 288 |
| | 9 or more | 432 |
| Individual adults | 3 through 5 | 180 |
| | 6 through 8 | 360 |
| | 9 through 11 | 540 |
| | 12 or more | 720 |
| Nursing females | 3 through 5 | 576 |
| | 6 through 8 | 720 |
| | 9 through 11 | 864 |
| | 12 or more | 1080 |

(c) *Space requirements for primary enclosures acquired on or after August 15, 1990.*

(1) Primary enclosures shall be constructed and maintained so as to provide sufficient space for the animal to make normal postural adjustments with adequate freedom of movement.

(2) Each rabbit housed in a primary enclosure shall be provided a minimum amount of floor space, exclusive of the space taken up by food and water receptacles, in accordance with the following table:

| | Individual weights | | Minimum floor space | | Minimum interior height | |
| --- | --- | --- | --- | --- | --- | --- |
| kg | lbs | m2 | ft2 | cm | in |
| Individual rabbits (weaned) | <2 2-4 4-5.4 >5.4 | <4.4 4.4-8.8 8.8-11.9 >11.9 | 0.14 0.28 0.37 0.46 | 1.5 3.0 4.0 5.0 | 35.56 35.56 35.56 35.56 | 14 14 14 14 |

| | Weight of nursing female | | Minimum floor space/female & litter | | Minimum interior height | |
| --- | --- | --- | --- | --- | --- | --- |
| kg | lbs | m2 | ft2 | cm | in |
| Females with litters | <2 2-4 4-5.4 >5.4 | <4.4 4.4-8.8 8.8-11.9 >11.9 | 0.37 0.46 0.56 0.70 | 4.0 5.0 6.0 7.5 | 35.56 35.56 35.56 35.56 | 14 14 14 14 |

(3) Innovative primary enclosures that do not precisely meet the space requirements of [paragraph (c)(2)](/on/2024-07-03/title-9/section-3.53#p-3.53(c)(2)) of this section, but that do provide rabbits with a sufficient volume of space and the opportunity to express species-typical behavior, may be used at research facilities when approved by the Institutional Animal Care and Use Committee, and by dealers and exhibitors when approved by the Administrator.

[[32 FR 3273](https://www.federalregister.gov/citation/32-FR-3273), Feb. 24, 1967, as amended at [55 FR 28883](https://www.federalregister.gov/citation/55-FR-28883), July 16, 1990]