Biomedical Engineering Reference
In-Depth Information
Perches and Other Enrichment Devices
Perches are recommended for most nonhuman primate
cages and strongly suggested for cage enrichment by
federal regulations (
US Department of Agriculture, 1991
),
guidelines (
National Research Council (Institute for
Laboratory Animal Research), 2011
), and welfare advo-
cates (
Rennie and Buchanan-Smith, 2006; Jennings et al.,
2009
). When perches are available, the animals will use
them (
Williams et al., 1988; Reinhardt, 1990; Bayne et al.,
1992; Shimoji et al., 1993; Neveu and Deputte, 1996
).
Perches should be easily sanitized and resistant to corrosion
or destruction or consumption by the cage residents.
Perches may be constructed of stainless steel, aluminum,
polyvinyl chloride pipe, or other similar thermoneutral
material. If the cage has a squeeze back, it should move
forward unimpeded by the perch (
Watson, 1991
). The
distance between the top of the perch and the cage ceiling
should accommodate the resident primate without causing
it to hunch excessively. Most cages should have permanent
perches, although a few cages with removable perches
might be retained for use by debilitated animals or others
for whom a perch might be hazardous.
A variety of other environmental enrichment devices or
toys may be mounted on or placed in the cage to allow
animals to engage in manipulative and play behaviors.
Examples of these devices include malleable rubber or
plastic toys of various shapes, swings, and aluminum rings.
The range of devices that may be purchased or easily
constructed are limited only by the resources of the insti-
tution and the imagination of the animal care staff. See
Chapter 6 for more information on enrichment options and
considerations. Internal devices that take up floor space
should not be included as part of the minimum required
floor area (
National Research Council (Institute for Labo-
ratory Animal Research), 2011
).
must be housed singly owing to research requirements.
They can also be used for small-group housing.
Containment Housing
As determined by an appropriate risk assessment, experi-
ments involving use of infectious agents or certain chem-
icals may require animals to be housed in a primary
biosafety containment system with inward flow ventilation
to isolate personnel and other animals from exposure to
aerosols from infected animals (
US Department of Health
and Human Services, 2007
). Temporary cage-level bio-
containment isolation systems may be devised using flex-
ible clear plastic film material that surrounds the cage. The
air exhausted from these systems are HEPA filtered
(
Johnson et al., 2008
). Commercially manufactured
primary containment systems are available for housing
nonhuman primates in a biocontainment environment
(
Erwin and Landon, 1992
). Regardless of the system used,
it will be necessary to access the animals to perform sani-
tation tasks, provide food and water, and perform veteri-
nary and research related procedures. For these activities
staff will need to don appropriate personal protective
equipment. Additionally, facilities for secondary contain-
ment should be appropriately designed to allow appropriate
and adequate containment (
Lehner et al., 2009
).
GROUP ENCLOSURES
Group housing of nonhuman primates usually implies more
than two animals in a primary enclosure. Group-housed
nonhuman primates may be located in three types of
facilities: indoor facilities which are totally environmen-
tally controlled, sheltered or indoor/outdoor facilities in
which only the indoor portion is environmentally
controlled, and outdoor facilities which are not environ-
mentally controlled. Major factors in the selection of the
housing method for groups of nonhuman primates are the
climate encountered at the institution and the species being
housed. The local climate is of paramount importance in
determining if outdoor enclosures are feasible. In the USA,
the provision of shelter from environmental elements is
a regulatory requirement, and adequate shelter must be
provided (
US Department of Agriculture, 1991
). The
shelter(s) must be designed so that all animals can seek
shelter simultaneously. Animals in outdoor group enclo-
sures should have opportunities to seek an adequate envi-
ronment to assist in controlling body temperature. For
example, animals may modify their immediate surround-
ings by huddling in sheltered areas with other animals, thus
reducing the loss of body heat. The primates should be
allowed to seek the sun or shade, climb above the ground,
or use water sprinklers in hot weather to keep cool. If
supplemental heat is provided, the heated area must be
Other Caging Options and Considerations
Transfer cages (boxes) should be designed to allow easy
movement of animals from their home cage into the
transfer cage. Cages should be selected or designed to
accommodate transfer boxes. Various accessories such as
connecting tunnels or mobile cages (
Seier and de Lange,
1996
), view-ports (pop-out porches), enrichment panels,
panels to facilitate unsedated venepuncture from trained
animals, and other accoutrements are available from some
caging manufacturers or can be fabricated in house. See
Chapter 6 for some examples. Activity cages (larger and
with more enrichment devices than the primary cage) can
be used on a rotational basis. Activity cages allow for more
locomotion options, expression of normal behavior, and
reductions in abnormal behaviors (
Szostak, 1987; Bryant
et al., 1988; Kessel and Brent, 1995a,b; Tustin et al., 1996
)
and are especially appropriate for nonhuman primates that
