IACUC Policy on Animal Housing and Environmental Enrichment

Overview
General Information about Environmental Enrichment
Policy Statement
Implementation
Table of Standard and Additional Enrichment

Overview

This policy outlines the types of standard housing used for laboratory animal species at UCI and the types of environmental enrichment materials or practices that may be used to enhance species-specific behavior and reduce distress and anxiety in laboratory animals.

The Guide for the Care and Use of Laboratory Animals¹ ("The Guide") states that:

"A good management program provides the environment, housing, and care that permit animals to grow, mature, reproduce, and maintain good health; provides for their well-being; and minimizes variations that can affect research results."
"Animals should be housed with the goal of maximizing species-specific behaviors and minimizing stress-induced behaviors."
"Depending on the animal species and use, the structural environment should include resting boards, shelves or perches, toys, foraging devices, nesting materials, tunnels, swings, or other objects that increase opportunities for the expression of species-typical postures and activities and enhance the animals' well-being."
"Consideration should be given to an animal’s social needs. The social environment usually involves physical contact and communication among members of the same species (conspecifics), although it can include non-contact communication among individuals through visual, auditory, and olfactory signals."

The Animal Welfare Act (AWA) mandates "environmental enrichment" for nonhuman primates² by specifying that there must be a "program for the psychological well-being of nonhuman primates". Exercise requirements for dogs³ are also specified in the AWA.

General Information

Standard housing refers to the type(s) of housing approved by IACUC and ULAR for housing the species concerned.

Environmental enrichment refers to additions to an animal's environment with which it can interact. The goal is to allow animals to express a range of species-typical behaviors which may enhance their well-being. Examples of environmental enrichment include the following:

Allowing control over the environment such as providing opportunities for:
- nest-building
- areas for animals to hide from threatening situations
- exercise
Novel items (e.g. food, toys, climbing structures).
Group housing to allow interaction with conspecifics.

The type of environmental enrichment provided depends on the species of animal, type of housing, space available, research needs, husbandry practices and other operational needs.

Policy Statement

In compliance with Federal Animal Welfare Regulations and guidance and in consideration of the physical and social needs of research animals the IACUC requires that appropriate environmental enrichment be provided to standard animal housing unless there is scientific justification, approved by the IACUC that precludes the use of environmental enrichment materials or practices.

Implementation

All animals housed for use in research, teaching or testing purposes at UCI must be housed in an animal facility or other space approved by the IACUC.
Each animal housing room (or isolated housing unit) will contain a single species unless special housing arrangements have been made with ULAR for compatible species.
Standard housing is provided by ULAR on a recharge basis, unless the IACUC has approved that housing can be provided and maintained by research groups. For certain species of animals that are not currently or routinely housed at UCI, research groups may be responsible for set-up costs to provide specialized equipment for maintaining the animals.
Changes to the standard housing and environmental enrichment described in Table 1 below are not permitted except under the following circumstances:
- Changes are described in the animal use protocol and approved by the UCI IACUC.
- Changes are prescribed by the ULAR Veterinary Services group for animal health or welfare reasons.
Enrichment materials or practices should not significantly alter the species-appropriate standards for husbandry, nutrient requirements or housing, as described in The Guide, unless these deviations are described and approved by the IACUC in the animal use protocol.
Provision of environmental enrichment other than the Standard or Allowed Environmental Enrichment described in Table 1 must be described in the IACUC protocol. If the standard housing and enrichment for the species cannot be used, a justification must be submitted and approved by the IACUC.
For USDA-covered species, a written record of the environmental enrichment items provided will be kept along with the daily husbandry records.

References

¹ Guide for the Care and Use of Laboratory Animals (National Academies Press, 1996), pages 21, 22, 36 and 37.
² Animal Welfare Regulations, 9 CFR Chapter 1, Subchapter A, Part 3, Subpart D, Section 3.81
³ Animal Welfare Regulations, 9 CFR Chapter 1, Subchapter A, Part 3, Subpart A, Section 3.8

Table of Standard and Additional Enrichment

Species (common name)	Standard Housing	Standard Environmental Enrichment Required (ULAR-Provided)	Additional Enrichment Allowed/Recommended (Research Group Must Provide)
Mice	Solid-bottom plastic cage with a wire bar lid that serves as a food hopper and water bottle holder. Filter top (microisolator lid). Cages may be placed on ventilated racks providing filtered air directly to the cage, or placed on static racks. Water bottle. Contact bedding consisting of commercially-available corn cob particles, wood chips, cotton, or paper products specifically made for laboratory animals. Commercially-available laboratory rodent diets approved by ULAR.	Group-housed if compatible (e.g. adult males from different litters cannot be housed together). Nesting material made from paper or cotton fibers. (e.g. Nestlets).	Disposable cardboard mouse houses ("Shepherd Shacks") Plastic mouse houses (must be cage-washer safe).
Rats	Solid-bottom plastic cage with a wire bar lid that serves as a food hopper and water bottle holder. Filter top (microisolator lid) may be used. Cages may be placed on ventilated racks providing filtered air directly to the cage, or placed on static racks. Water bottle. Contact bedding consisting of commercially-available corn cob particles, wood chips, cotton, or paper products specifically made for laboratory animals. Commercially-available laboratory rodent diets approved by ULAR.	Group-housed if compatible. Paper towels for shredding.	Sterilized wooden tongue depressors for chewing. Sterilized Nyla bones for chewing. Plastic rat houses (must be cage-washer safe).
Rabbits	Sanitizable cage of appropriate size with suspended floor. Water bottle or lixit for automatic watering. Commercially-available laboratory rabbit chow approved by ULAR.	Sanitizable toys such as plastic chains or balls, stainless steel rings, PVC pipe. Small portions of timothy hay, other grass hay, alfalfa hay, fresh spinach or fresh kale offered one to three times per week in a sanitizable feeder, or on cage bottom.	Group-housed if compatible. Small amounts of other fresh vegetables such as carrots and Romaine lettuce. Small amounts of dried banana chips apples or pineapple.
Pigs	Indoor pens with sanitizable surfaces. Lixit for automatic watering. Wood chip contact bedding in solid bottom pens. Sanitizable food bowls. Nutritionally complete commercially available diet for laboratory pigs approved by ULAR.	Group-housed if pen size is adequate and if animals arrive together and are compatible. Social contact with other pigs if possible. Positive human interaction (e.g. patting, scratching, rubbing back), if pigs are acclimatized to this. Sanitizable toys (e.g. Kong toys, plastic balls). Stiff brush attached to pen wall for pig to rub and groom skin)	Small amounts of food treats such as fresh vegetables, yogurt or fruit.
Cats	Housed in large indoor holding rooms in compatible groups. Space allocation is at least the minimum required by Animal Welfare Act. Cats may be housed in smaller individual cages temporarily (e.g. after surgery). Sufficient litter boxes appropriate for the number of cats. Fresh water in sanitizable bowls. Nutritionally complete, commercially available dry cat food approved by ULAR. • Group-housed if compatible.	Group-housed if compatible. Positive human interaction daily (e.g. patting, scratching, rubbing back). Multi-level shelves for resting and climbing. Sanitizable or washable toys and items such as scratching posts, toy mice and balls. Guinea Pigs
Guinea Pigs	Polystyrene, polycarbonate or other high-temp plastic solid bottom cage with a wire bar lid that serves as a water bottle holder. Filter top (microisolator lid) may be used. Cages may be placed on ventilated racks providing filtered air directly to the cage, or placed on static racks. Water bottle. Sanitizable food bowl. Contact bedding consisting of commercially-available corn cob particles, wood chips, cotton, or paper products specifically made for laboratory animals. Commercially-available laboratory guinea pig diets approved by ULAR.	Group-housed if compatible.	Plastic guinea pig houses (must be cage-washer safe). Disposable cardboard guinea pig houses ("Shepherd Shacks"). Small quantities of Timothy or alfalfa hay. Sanitizable toys such as balls or Kong toys.
Hamsters	Solid-bottom plastic cage with a wire bar lid that serves as a food hopper and water bottle holder. Filter top (microisolator lid). Cages may be placed on ventilated racks providing filtered air directly to the cage, or placed on static racks. Water bottle. Contact bedding consisting of commercially-available corn cob particles, wood chips, cotton, or paper products specifically made for laboratory animals. Commercially-available laboratory rodent diets approved by ULAR.	Group-housed if compatible. Nesting material made from paper or cotton fibers.	Disposable cardboard hamster houses ("Shepherd Shacks") Plastic hamster houses (must be cage-washer safe).
Gerbils	Solid-bottom plastic cage with a wire bar lid that serves as a food hopper and water bottle holder. Filter top (microisolator lid). Cages may be placed on ventilated racks providing filtered air directly to the cage, or placed on static racks. Water bottle. Contact bedding consisting of commercially-available corn cob particles, wood chips, cotton, or paper products specifically made for laboratory animals. Commercially-available laboratory rodent diets approved by ULAR.	Group-housed if compatible. Nesting material made from paper or cotton fibers.	Disposable cardboard gerbil houses ("Shepherd Shacks") Plastic gerbil houses (must be cage-washer safe).
Birds	Sanitizable wire cages or large flight cages. Perches. Fresh water in water bottle or sanitizable bowls. Food containers and water bottles should be designed and positioned to minimize fecal contamination. Shelter from sun, rain and extreme weather conditions if housed in outdoor aviaries. Nutirionally-complete food appropriate for the species. Dietary supplements appropriate for the species (e.g. cuttlefish bones, shell grit, fresh greens).	Group-housed if compatible. Mirrors if housed singly. Nesting materials and enclosures for breeding.	Sanitizable mirrors, swings, ladders, or other types of perches as appropriate for the species.
Xenopus	Aquaria made of sanitizable materials. Static or flow-though water system. Water filtered or conditioned to remove/inactivate chlorine and chloramine. Nutritionally-complete commercially-available food.	Group-housed if compatible. Shelter structures such as plastic guinea pig houses or large PVC pipes to allow frogs to hide.	Small amounts of dietary supplements such as blood worms, chopped beef heart, and chopped liver.
Fish	Aquaria made of sanitizable materials. Static or flow-though water system. Water filtered or conditioned to remove/inactivate chlorine and chloramine. Nutritionally-complete fish food appropriate for the species.	Group housed if compatible.
Reptiles	Sanitizable, secure enclosures of appropriate size and configuration for the species. Opportunity for animals to thermoregulate, or a constant temperature range in the thermoneutral zone for the species. Water and nutritionally complete food appropriate for the species.	Sanitizable objects to provide hiding places.

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