University Committee on Animal Care and Supply (UCACS) Standard Operating Procedure (SOP) SOP # I201 Title Environmental Enrichment for Rodents, Rabbits, Guinea Pigs 1. Purpose The purpose of this SOP is to describe an environmental enrichment program for rodents, rabbits and guinea pigs. 2. General Information/Responsibility Environmental enrichment refers to the addition of articles to an animal s environment with which it can interact. Environmental enrichment must be provided to all rodents, rabbits and guinea pigs, unless scientific justification for a lack of enrichment is indicated in the Animal Use Protocol (AUP) and specifically approved by the Animal Research Ethics Board (AREB). Environmental enrichment enhances the physical and psychological well- being of a captive animal by providing opportunities to express species- typical, non- injurious behaviours and to promote physical and mental health, thus enhancing animal welfare. The enrichment should be biologically relevant (e.g. playing, hiding, socializing, foraging, nesting) to avoid loss of its enriching value over the duration of the animal use. The Principal Investigator (PI) and the Facility Veterinarian must approve novel enrichment materials before their introduction. Furthermore, to avoid the introduction of unwanted experimental variables, all rodents, rabbits or guinea pigs in a study should be provided with the same type of enrichment. Responsibility for enrichment: Principal Investigator, animal care staff, UCACS. 3. Equipment/Materials 1. Nesting material 2. Shelters 3. Sand bath (gerbils) 4. Toys (guinea pigs see below) 5. Toys (rabbits plastic balls, dumbbells, syringe cases) 6. Dietary supplements (if permitted) 7. Other types of approved enrichment Page 1 of 8
4. Procedure A. Social Contact 1. Mice are social animals and pair or group housing is a critical environmental enrichment as it creates new and unpredictable situations to which the animal must react. A social group leads to an in crease of alertness and exploratory behaviour and provides diversion, occupation and security. 2. Pair or group house same gender mice at all times with the following exceptions: Incompatibility due to aggression (e.g. breeding age males) Pregnant females based on strain disposition (may cannibalize young if left with male or other females) Specific AUP approved by the AREB 3. Locate individually housed mice within sight of one another when possible. 1. Rats are social animals and pair or group housing is a critical environmental enrichment as it creates new and unpredictable situations to which the animal must react. A social group leads to an increase of alertness and exploratory behavior and provides diversion, occupation, and security. Positive interaction with humans (e.g., handling, training, and socializing) benefits both the animal and the handler, and ultimately the outcome of the experiment. 2. Pair or group house rats at all times with the following exceptions: Incompatibility Specific protocol approved by the UCACS 3. Provide individually housed rats with human contact where appropriate 4. Locate individually housed rats within sight of one another when possible 1. Hamsters are solitary animals, and will often fight if housed together. Individually house hamsters unless they are littermates raised together pair or group house animals of the same gender Closely monitor littermates for aggression once they reach sexual maturity Do not group house: pregnant females, incompatible animals 1. Gerbils are social animals and pair or group housing is the most complex type of enrichment as it always creates new and unpredictable situations to which the animal must react. A social group leads to an increase of alertness and exploratory behavior and provides diversion, occupation, and security. Positive interaction Page 2 of 8
with humans (e.g., handling, training, and socializing) benefits both the animal and the handler, and ultimately the outcome of the experiment. 2. Pair or group house gerbils at all times with the following exceptions: Incompatibility Specific protocol approved by the UCACS 3. Provide individually housed gerbils with human contact where appropriate 4. Locate individually housed gerbils within sight of one another when possible e. Guinea Pig 1. Guinea pigs are social animals and pair or group housing is the most complex type of enrichment as it always creates new and unpredictable situations to which the animal must react. A social group leads to an increase of alertness and exploratory behavior and provides diversion, occupation, and security. Positive interaction with humans (e.g., handling, training, and socializing) benefits both the animal and the handler, and ultimately the outcome of the experiment. 2. Pair or group house same- sex guinea pigs at all times with the following exceptions: Incompatibility Specific protocol approved by the UCACS 3. Provide individually housed guinea pigs with human contact where appropriate 4. Locate individually housed guinea pigs within sight of one another when possible f. Rabbit 1. Rabbits are social animals and pair or group housing is the most complex type of enrichment as it always creates new and unpredictable situations to which the animal must react. A social group leads to an increase of alertness and exploratory behavior and provides diversion, occupation, and security. Positive interaction with humans (e.g., handling, training, and socializing) benefits both the animal and the handler, and ultimately the outcome of the experiment. 2. Whenever possible, pair or group- house female rabbits. 3. House males singly as pair housing often results in fighting. 4. Exceptions for pair or group- housing include: Incompatibility Specific protocol approved by the UCACS 5. Provide individually housed rabbits with human interaction where appropriate 6. Locate individually housed rabbits within sight of one another when possible Page 3 of 8
B. Housing System 1. House mice in solid- bottom cages with ample contact bedding for tunneling unless specifically described in the AUP and approved by the AREB 2. Provide at least the minimal space recommendations for a standard mouse cage (~450 cm 2 ). Trio- breeding: 2 females, 1 male and up to 2 litters until weaning After weaning: 10 mice if < 10 g 7 mice if 10-15 g 5 mice if 15-25 g 4 mice if > 25 g 1. House rats in solid- bottom cages with contact bedding, unless specifically described in the protocol and approved by the UCACS 2. Provide at least the minimal space recommendations for a standard rat cage (~140 in 2 ; 900 cm 2 ) 1 female, 1 male, and one litter until weaning After weaning: 3 rats if <300 g 2 rats if >300 g 1. House hamsters in solid- bottom cages with ample contact bedding for tunneling unless specifically described in the AUP and approved by the AREB 2. Provide a cage with at least 120 cm 2 (19 in 2 ) of floor space, and at least 18 cm (7 ) high. 1. House gerbils in solid- bottom cages with ample contact bedding for digging and tunneling, unless specifically described in the protocol and approved by the UCACS 2. Provide a cage with at least 116 cm 2 (18 in 2 ) of floor space per animal, at least 15 cm (6 ) high. e. Guinea Pig 1. Guinea pigs startle easily; minimize noise and sudden movements near housing enclosures 2. House guinea pigs in solid- bottom cages with contact bedding, unless specifically described in the protocol and approved by the UCACS 3. Cage floor space and height should meet or exceed CCAC recommendations: Page 4 of 8
Guinea Pig Size Floor Area/Animal Height <350 g 300 cm 2 (~46 in 2 ) 18 cm (7 ) >350 g 650 cm 2 (~100 in 2 ) 22 cm (8.5 ) f. Rabbit 1. If possible, group house rabbits in floor pens or open- top solid- bottom cages with contact bedding. Otherwise, singly house rabbits to avoid fighting. 2. Wire- bottom cages require a solid area (~8 X 8 ), such as a rubber mat, to minimize foot problems 3. Rabbits housed in cages should be provided regular opportunity for exercise (eg play pens) unless prohibited by the protocol 4. Cage floor space and height should meet or exceed CCAC recommendations: Rabbit Size Floor Area/Animal Height Up to 4 kg 0.37 m 2 (~4 ft 2 ) 0.4 m (15.6 ) 4-5.4 kg 0.47 m 2 (~4 ft 2 ) 0.45 m (17.6 ) Doe with litter 0.93 m 2 (~10 ft 2 ) C. Nesting material 1. Provide ample nesting material (e.g. Nestlet, Envirodri ) in every cage 2. Transfer portions of the nest to the clean cage with the animals with additional nesting material and a new shelter if necessary 1. Provide nesting material (eg Nestlet, Envirodri ) in every cage 2. Transfer portions of the nest to the clean cage with the animals, with additional nesting material and a new shelter if necessary 1. Provide ample nesting material (e.g. Nestlet, Envirodri ) in every cage 2. Transfer portions of the nest to the clean cage with the animals with additional nesting material and a new shelter if necessary 1. Provide ample nesting material (eg Nestlet, Envirodri ) in every cage 2. Transfer portions of the nest to the clean cage with the animals, with additional nesting material and a new shelter if necessary e. Guinea Pig f. Rabbit Page 5 of 8
D. Shelters 1. Provide a cellulose- based or plastic shelter or tube 2. Shelters should provide enough cover for all cage occupants 1. Provide a plastic shelter or tube 2. Shelters should provide enough cover for all cage occupants 1. Provide a cellulose- based or plastic shelter or tube 1. Provide a cellulose- based or plastic shelter or tube a. Guinea Pig 1. Provide a plastic shelter or tube 2. Shelters should provide enough cover for all cage occupants b. Rabbit 1. Provide shelters such as large plastic tubes, plastic houses, plastic drums cut in half or plastic buckets to rabbits housed in floor pens or open cages 2. Shelters should provide enough cover for all enclosure occupants 3. Provide raised platforms or flat- topped shelters if possible to encourage climbing and jumping, and provide a lookout E. Dietary Enrichment 1. Dietary enrichment is not routinely provided 2. Provide hamsters with dietary supplementation only as approved by the PI and the Facility Veterinarian (e.g. Cheerios, autoclaved sunflower seeds, rodent treats) 3. Provide a chewing device (e.g. nylon bone, wood block) 1. Dietary enrichment is not routinely provided 2. Provide rats with dietary supplementation only as approved by the PI and the facility veterinarian (eg Cheerios, autoclaved sunflower seeds, Milkbones ) 1. Dietary enrichment is not routinely provided 2. Provide hamsters with dietary supplementation only as approved by the PI and the Facility Veterinarian (e.g. Cheerios, autoclaved sunflower seeds, rodent treats) Page 6 of 8
3. Provide a chewing device (e.g. nylon bone, wood block) 1. Dietary enrichment is not routinely provided 2. Provide gerbils with dietary supplementation only as approved by the PI and the facility veterinarian (eg Cheerios, autoclaved sunflower seeds, rodent treats) e. Guinea Pig 1. Provide autoclaved hay or alfalfa cubes daily or at least twice a week 2. Provide other dietary supplementation only as approved by the PI and the facility veterinarian f. Rabbit 1. Provide autoclaved hay or alfalfa cubes daily or at least twice a week 2. Provide other dietary supplementation only as approved by the PI and the facility veterinarian F. Other Types of Enrichment 1. Ensure the enrichment device is sterilized prior to introduction into the cage. Running wheels Nylabones Hardwood blocks (SPF grade) Plastic or metal shower curtain, or binder rings attached to cage top 1. Chewing device Provide a chewing devise (eg Nylabone, SPF grade hardwood block) to rats on a powdered diet 1. Ensure the enrichment device is sterilized prior to introduction into the cage. Running wheels 2. Gerbil 3. Guinea Pig 1. Toys Provide metal or plastic chains or rings attached to the cage side, or other approved devices that the guinea pig can manipulate 4. Rabbit Page 7 of 8
1. Toys Provide whiffle balls, dumbbells, syringe cases, or other approved devices that the rabbit can manipulate 5. Safety Wear appropriate Personal Protective Equipment (PPE) when working with rodents, rabbits and guinea pigs, observe good hygiene, and be aware of potential allergy, zoonosis, and injury risks. Contact the Facility Veterinarian or Workplace Safety and Environmental Protection (966-4700) for more information. Post contact information for emergency assistance in a conspicuous location within the animal facility. 6. Potential Complications and Troubleshooting N/A 7. References 1. Enrichment Strategies for Laboratory Animals. ILAR Journal, 46 (2), 2005. (http://dels- old.nas.edu/ilar_n/ilarjournal/46_2/html/) 2. Making Lives Easier for Animals in Research Labs. Animal Welfare Institute, 2007 (http://www.awionline.org/ht/a/getdocumentaction/i/4590) 8. Revision History List the changes made during the most recent revision, as well as the reasons for the changes. Date Created: 13 Oct 2010 Written by: C. Wheler SOP Review and Revision History Revision Number Review/Revision Date Reviewer 01 19 Nov 2012 UCACS Page 8 of 8