II. LABORATORY
ANIMAL FACILITIES
A. INTRODUCTION
A laboratory animal facility must facilitate
research by minimizing undesirable experimental variables while providing
for the physiological, social and behavioural requirements of the animal.
Different research projects and/or different species of animals often require
differing facilities and environments. To accommodate such needs, an animal
facility must have separate areas for carrying out different functions,
specialized rooms and equipment, and closely controlled environments.
Animal facilities providing the appropriate
environment are expensive to build. It is, therefore, imperative that every
effort be made to ensure that any proposed new facility is programmed,
designed, and built to meet the size and scope of current animal use, and
yet to be versatile enough to allow flexibility in the years to come.
A number of alternative design approaches
to achieve any given functional need are available. For example, the Handbook
of Facilities Planning, Volume 2: Laboratory Animal Facilities (Ruys,
1991), is a useful reference for the planning phase. Other references and
assistance may be obtained from the Canadian Council on Animal Care (CCAC).
It is strongly recommended that the CCAC be involved at an early stage
in the planning phase and that plans be evaluated by the Council before
the start of construction.
B. LOCATION
Animal facilities should be located so
as to minimize public access or through-traffic, as well as the movement
of animals, cages, waste, etc., through public corridors and elevators.
The facilities should be readily accessible by animal users yet easily
secured. Direct access to the outside for deliveries and disposal is desirable.
Facilities located on higher floors should be accessed by a minimum of
two elevators, one for clean and one for dirty materials, unless appropriate
measures are taken to clean and sanitize a single elevator following the
transport of dirty materials. For very small and/or satellite facilities,
alternative precautions to minimize contamination may be acceptable.
C. MECHANICAL SERVICES
Heating, ventilation and air conditioning
systems for animal facilities are usually quite sophisticated and costly
(see also The Environment). Placement of these systems should allow servicing
to proceed with a minimum of disturbance to the animals and the work patterns
in the facilities. This may be accomplished by placing mechanical services
on a separate service floor immediately above the animal facilities so
that maintenance does not require entry into the animal facilities. It
is, however, more common to locate the mechanical systems in the ceiling
space between floors. In this location all access to the mechanical systems
should be from the corridors, and not from the animal rooms or restricted
zones such as biohazard areas.
D. DESIGN
The size of animal rooms should be based
on the species to be maintained, and a multiple of the size of pens, cages
or cage racks to be contained, allowing for adequate ventilation and servicing.
Animal rooms should be designed for ease of sanitation and hence should
have a minimum of built-in equipment. In many cases, a single, small sink
for hand washing may be all that is required. The placement of the animal
rooms and ancillary rooms will depend on the species, experimental use
and microbial quality. The design should facilitate traffic flow from cleaner
to dirtier areas. Rooms requiring frequent access by investigators should
be located near the entry to the facilities to minimize traffic.
E. MAJOR FUNCTIONAL
DIVISIONS
The design of an experimental animal facility
should take into consideration the needs of the experimental animal and
the requirements and convenience of the scientists and technical staff.
Good animal care facilities must provide for several separate functions
and sometimes highly specialized areas (Clough, 1986; Home Office, 1986).
Animal holding rooms should be separate from experimental rooms. Important
aspects of good design are provision for efficient and effective sanitation,
efficient work traffic patterns and orderly expansion. The following identifies
the major functional areas in an ideal animal facility.
1. Animal Reception
Area
The reception area should be situated so
that animals entering it do not pass through holding or experimental areas.
Similarly, waste material should not pass through the receiving area. It
should provide sufficient space for the uncrating and initial examination
of animals as well as for holding them under appropriate environmental
conditions until they are relocated either in the conditioning area or
one of the animal rooms.
2. Conditioning Rooms
Conditioning rooms are ones in which animals
may be maintained for detailed health examination, observation and conditioning
in preparation for experimentation. The availability of a proper conditioning
room(s) is particularly important where random-source animals are being
acquired (e.g., some dogs, cats, non-human primates, and animals from the
wild). Under certain circumstances, where space permits, it may be possible
and even desirable to immediately house animals in an experimental room,
provided the animals are derived from a single source and contact with
other animals can be avoided.
3. Holding Rooms
Separate animal holding rooms should be
available for each species, from each source, and for each investigator's
project. Consequently, it is usually better to have many small rooms rather
than a few large ones. Exceptions can be made where investigators are using
the same species from the same source for different projects (e.g., antibody
production in rabbits). Mixing should be limited to compatible social and
health status groups within a single species. Where mixing of species is
necessary, some degree of isolation may be achieved by specialized room
design, equipment and/or cage selection. Cross-contamination can be minimized
when controlled airflow cubicles, portable laminar airflow units, and various
forms of isolator cages are used. The use of radioisotopes, infectious
agents and highly toxic substances requires special holding rooms. Rooms
suitable for special purposes may also be required (e.g., breeding colonies,
controlled environmental studies and for the housing of both farm and wild
animals).
It is important, when designing holding
rooms to consider possible future uses of these facilities. Where animal
use has been consistent over the years, it may be acceptable to design
all animal rooms for specific species use. However, in many facilities,
animal use fluctuates considerably, making flexibility extremely important.
A flexible holding room is one which meets the acceptable requirements
for housing different species.
4. Quarantine/Isolation
Rooms
Within the facility, but apart from the
conditioning area, quarantine/isolation rooms may be required to separate
sick animals or those animals returned to the facility after use in an
investigator's laboratory.
5. Experimental and
Treatment Facilities
Experimental manipulations should not be
carried out in animal holding rooms, unless mandated by experimental design
or containment needs and approved by the Animal Care Committee (ACC). Separate
facilities should be available to allow for surgery, euthanasia, etc.;
however, not all need to be located within the animal facilities. The animal
holding rooms should therefore be located as conveniently as possible to
the research and teaching laboratories.
Animal facilities may include rooms for
some or all of the following: pre-surgical preparation, surgery, post-operative
recovery (see also Standards for Experimental Animal Surgery), radiology,
necropsy, diagnostic services, special diet preparation, dispensary, etc.
The design and organization of special facilities will depend on their
intended scope and use; however, even very modest facilities will usually
need to provide a special area or procedures room for minor surgery and/or
treatments, and a separate necropsy room.
Separate diagnostic areas for laboratory
animal diseases may not be feasible for smaller institutions. In such cases,
arrangements for provision of such services should be made.
6. Support Facilities
a) Facilities for Washing and Sterilizing
Equipment
Facilities for washing and sterilizing
equipment and supplies should be designed for this purpose and be located
so as to minimize disturbance to animals, staff, and neighbours. Ventilation
should be sufficient to prevent odours, excess heat and steam from affecting
the rest of the facility. Sinks for hand-washing and for cleaning specialized
pieces of equipment are useful. Large, deep sinks are useful. Autoclaves
and other special equipment may be located in this area. Ideally, the wash-up
area should provide for the separation of clean and dirty equipment. If
spray washing of either cages or racks is to be used, provision of a walled-off
bay with hot and cold water and disinfectant dispenser is recommended.
b) Waste Disposal
The waste disposal area should provide
for proper storage of animal material, excrement, soiled bedding, etc.
Waste awaiting collection should be placed in a dedicated refrigerated
container or cold room. Waste stored outside the facility should be in
secure covered containers. Facilities must comply with local bylaws governing
waste storage and disposal. Toxic, infectious or radioactive waste handling
must comply with institutional, federal (HWC/MRC, 1990) and other regulations
(see also Occupational Health and Safety).
c) Food and Bedding Storage
Small quantities of food and bedding may
be stored in an animal room in suitable, covered containers. Separate cool
(<15C), dry, vermin-proof facilities should be available for the storage
of food to minimize spoilage and contamination. Food for farm animals,
such as hay, may contain vermin and should be isolated from the food and
bedding of other laboratory animals.
d) Equipment Storage
Lack of sufficient storage space is one
of the most frequent and more serious deficiencies encountered in facility
design. Equipment storage should not be permitted in halls, corridors,
or in rooms housing animals. Even clean equipment designated for use in
an animal room should not be brought into the room until required. Areas
used for storing clean equipment should be separate from those where soiled
equipment is received. For the average facility, 11% storage space (of
net space) has been estimated as adequate. This proportion will need to
be increased up to 20% or more in facilities handling multiple species
under differing barrier conditions.
7. Personnel, Office
and Reception Areas
These functional areas may or may not be
combined. It is preferable to have these adjoining, but not within the
animal facilities. Enough office space is required to accommodate all administrative
staff, occasionally technicians, and the extensive records that must be
maintained.
8. Facilities for
Personnel
Personnel facilities should encourage high
standards of personal hygiene by providing staff with easily accessible
changing rooms with lockers, showers, sinks and toilets. Depending on the
design of the facility, these may have to be replicated in different zones.
Suitable protective clothing should be supplied (see also Occupational
Health and Safety).
Facilities should be provided for staff
rest periods, lunch, and for meetings. It is preferable that these areas
are adjoining, but not within the animal holding areas. An information
centre for staff (which could include books, journals, newsletters, catalogues,
and other related materials) would be helpful.
F. SECURITY
Access to experimental animal facilities
must be restricted in order to assure consistent environmental control
and to minimize interferences which might alter experimental results. Entry
and exit should be limited and the facilities maintained secure at all
times. Access should be allowed only to those who have a recognized need
to enter. Where a large number of investigators are using the same facilities,
it is often advisable to have individual room locks. Electronic access
control systems are available.
G. CONSTRUCTION GUIDELINES
FOR ANIMAL ROOMS
1. Floors and Drains
Floors should be seamless, durable, non-slippery,
impervious to water and easy to disinfect. They should be coved to the
walls to eliminate any sharp corners. They should slope towards any floor
drain(s) and the proper level of this slope should be verified in all new
construction. Recommended minimum pitch of sloped floors is 2.1 cm/m (0.25"/ft).
Special attention should be given to ensuring that this critical component
of floor construction is properly carried out.
It is recommended that drains be provided
with a flush mechanism so that a clean water seal (i.e., clean water in
the trap) can be maintained. However, care should be taken to assure that
the location of the flush mechanism does not interfere with cage or pen
placement. Drains should be provided with an adequate cover and pitch basket
trap. Drain and sewage lines should be at least 10.5 cm (4") in diameter.
Where dog excreta is washed down the drain, the diameter should be 15.0
cm (6"). Floor drains used for waste disposal should be placed at the end
of the main drainage line. Drains should be checked regularly to ensure
proper functioning, an effective water seal, and absence of insects. When
not in use, they should be capped and sealed.
Floor drains may not be required in rooms
designed solely to house small species. Instead wet vacuum devices which
permit sweeping and mopping with disinfectants or a cleaning compound may
be used.
2. Walls and Ceilings
Walls should be of an impervious material,
free of cracks, damage resistant, and easily cleaned and disinfected. With
these kinds of surfaces, noise reduction is difficult. Walls need not be
as resistant as the floor, provided that they are protected by a cove or
bumper guard. Pipe and service sleeves should be adequately closed off
and sealed so as to exclude vermin.
Ceilings within all rooms should be seamless
and free of cracks, with ceiling-wall joints well sealed. In some corridors,
it may be necessary to use ceiling tiles in order to allow access to the
mechanical systems. These tiles should be of a type which can be easily
sanitized and which prevent the entry of vermin into the ceiling space.
3. Doors
Animal room doors should be designed and
built to exclude vermin. Self-closing, metal or metal-covered doors with
obscurable viewing windows and kick plates are preferred. A replaceable
sweeper pad should be installed along the bottom if clearance exceeds 0.32
cm (1/8"). Recommended minimum door sizes are 107 cm (42") wide and 213
cm (84") high to allow free passage of equipment.
4. Windows
Exterior windows interfere with temperature
control due to radiation and conduction which may jeopardize animal health
and research results. They also interfere with photoperiod control. If
windows are already present these should be designed or altered to minimize
the above effects and to maximize cleanliness.
5. Corridors
Corridors should be strategically located
to facilitate traffic flow for the desired work patterns. It may be more
efficient to divide the animal facilities into zones with single corridors
than to use a double corridor (clean/dirty; supply/return) system.
Design standards for corridor floors, walls,
drains, coving, bumper guards, etc., should duplicate those for animal
rooms. Traffic corridors should be at least 1.82 m (6') wide. Other corridors
should be wide enough to allow free movement of personnel and equipment.
Walls should be free of any projecting fixtures up to a height of 213 cm
(84"); alternatively, these fixtures should be adequately protected with
guards. Exposed corners should be protected with steel plates or similar
durable material. All guards and fixtures should be sealed to exclude vermin.
Corridors leading to noisy areas should have double doors or similar noise-trapping
devices.
6. Services
Service lines should be located on the
floor above the animal facilities or in the ceiling space above the corridors
so as to eliminate in-room maintenance. Separate hot and cold water lines
should be supplied to each animal room for hand washing, cleaning, and
automatic watering. Every animal room should have at least one electrical
outlet; these should be water, insect and explosion-proof. Switches and
thermostats should be similarly designed. An emergency power source should
be available in case of a power failure.
H. CAGING
The size of caging chosen to house each
species should be appropriate for that species (see Appendix I).
Cages and pens must not only confine the
animals securely, but also ensure their comfort and safety by permitting
normal postural and behavioural adjustments, and provide for environmental
enrichment. Animals which are social by nature should not be singly housed
unless this is a necessary requirement of the research protocol, and approved
by the ACC (see also Social and Behavioural Requirements of Experimental
Animals).
Cages must provide for adequate ventilation,
satisfactory viewing and easy access to the animal. Food and water delivery
systems should be designed and located so as to allow the animal ready
access, but prevent contamination with excrement. Cage design should facilitate
cleaning and disinfection.
The intensity of light perceived by the
animal, the level of noise to which it is exposed, the ventilation and
temperature of its microenvironment are affected by cage design and material.
Considerable care should be used when choosing the appropriate caging for
a particular species and usage. Caging for animals other than the conventional
laboratory species requires special consideration.
Unless contra-indicated by the nature of
the research (e.g., nutritional studies) solid bottom cages should be chosen
(over suspended wire caging) for rodents and guinea pigs in that they permit
creation of microenvironments and facilitate provision of environmental
enrichment (see also Social and Behavioural Requirements of Experimental
Animals).
1. Shoebox Cages
The shoebox cages used mainly for small
rodents are particularly suited for breeding purposes. They are usually
made of plastics such as polycarbonate, polystyrene, and polypropylene.
Polycarbonate is clear, autoclavable, and resistant to most disinfectants.
Polystyrene and polypropylene do not withstand high temperatures well.
Polypropylene cages are translucent and offer animals more privacy, which
may be beneficial for some breeds or wild species. However, opaque cages
should not be placed on shelves above eye level since the animals within
cannot be readily observed.
A contact bedding (e.g., woodchip, ground
corncob, etc.) is used in the bottom of shoebox cages, allowing an animal
to form its own microenvironment. These cages are considered comfortable
for the animal, and the cage of choice for breeding. However, animals in
these cages are in contact with their own excreta and airflow is restricted.
Therefore, it is important to clean the cages frequently. Filter caps restrict
the airflow even more if cages are not individually ventilated. Faster
buildup of ammonia, carbon dioxide and moisture necessitates more frequent
cleaning (up to three times per week may be required). Shoebox cages can
be fitted with wire grid floors for certain projects which require that
there be no contact with excreta.
2. Larger Solid Bottom
Caging
Large plastic tubs have been used quite
successfully for group housing guinea pigs and rabbits. These tubs must
be strong enough to support the weight of the animals contained, have rounded
corners to facilitate cleaning and be resistant to disinfectants. These
are used with a contact bedding.
3. Suspended Cages
Suspended cages may be top or front opening.
Most top opening suspended cages use the rack shelves as the top for the
cage. The top opening cages are used primarily for smaller rodents, whereas
the front opening cages are better suited to guinea pigs, cats, dogs, rabbits
and non-human primates (NHP).
Most suspended cages have a floor of wire
mesh, steel rod, perforated metal or plastic, above a collection tray or
solid floor. It is extremely important that the size of the floor perforations
be appropriate for the species housed. They should be large enough to permit
excreta to freely pass through, but small enough to prevent foot and leg
injuries. The gauge of wire should support the animal's weight without
sagging. Floors should be designed so the animal's feet can grip during
movement, so as to minimize slipping. Wire mesh floors are not suitable
for guinea pigs nor for use in rodent littering cages.
In suspended cages, animals are not in
contact with their own excreta and the cages are usually well-ventilated.
The pans or trays can be cleaned more frequently than the cage, resulting
in less disturbance of animals. The animals, however, do not have the opportunity
to form their own microenvironment, and so control of the room environment
becomes more critical.
It is recommended that these cages be fabricated
from stainless steel or other woven metal alloys, corrosive resistant plastic
and/or in the case of some front opening cages, fibreglass. Fibreglass
is strong, warm-feeling, and more sound-resistant than other materials,
making it especially suitable for post-operative care. NHP and cats should
be supplied with one or more resting boards or perches at different levels.
A squeeze device built into the cage facilitates restraint of NHP.
4. Other Cages
Many cages are designed to meet specific
requirements. Examples include metabolism cages, mechanical exercise cages,
gang cages, transfer cages, restraint cages and walk-in cages (used for
housing groups of animals).
Additional information on housing large
domestic animals and fowl may be found in Agriculture Canada's Canadian
Farm Building Handbook (Agriculture Canada, 1988) (see also Farm Animal
Facilities and Environment) as well as Social and Behavioural Requirements
of Experimental Animals in this volume. Guidelines for the use of agricultural
animals have also been published in the U.S. (Curtis, 1988).
For information on cages for wild animals,
contact the Secretary-Treasurer of the Canadian Association of Zoological
Parks and Aquariums, c/o Metro Toronto Zoological Society, P.O. Box 280,
West Hill, Ontario M1E 4R5.
Information on shipping crates and transport
cages for a wide range of domestic, wild and laboratory animals may be
obtained from the most recent volume of Live Animals Regulations
(1992) of the International Air Transport Association (IATA), 2000 Peel
Street, Montreal, Quebec H3A 2R4.
All cage types must take into consideration
the well-being of the animal(s) during its confinement.
I. REFERENCES
AGRICULTURE CANADA. Publication 1822/E.
Canadian farm building handbook. Communications Branch, Agriculture Canada,
Ottawa, Ont., K1A 0C7. 1988.
CLOUGH, G. The animal house: Design, equipment
and environmental control. In: Poole, T.B., ed. UFAW (Universities Federation
for Animal Welfare) handbook on the care and management of laboratory animals.
6th Ed. New York, NY: Churchill Livingstone Inc. 1986: 108-158.
CURTIS, S.E., ed. Guide for the care and
use of agricultural animals in agricultural research and teaching, 1988.
Consortium for Developing a Guide for the Care and Use of Agricultural
Animals in Agricultural Research and Teaching, 309 West Clark Street, Champaign,
IL 61820.
HEALTH AND WELFARE CANADA/MEDICAL RESEARCH
COUNCIL. Laboratory biosafety guidelines. Ottawa, Ont.: Office of Biosafety,
Laboratory Centre for Disease Control, Health and Welfare Canada, 1990.
HOME OFFICE. Code of practice for the housing
and care of animals used in scientific procedures. Act Eliz. II 1986 c.14
Section 21, Animals (Scientific Procedures) Act. London: Her Majesty's
Stationary Office 1986: 4-8.
INTERNATIONAL AIR TRANSPORT ASSOCIATION.
Live Animals Regulations. 19th Ed. Montreal, Quebec: IATA, 1992.
RUYS, T., ed. Handbook of facilities planning.
Laboratory animal facilities. New York, NY: Van Nostrand Reinhold, 1991:
2.
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