Biomedical Engineering Reference
In-Depth Information
such as the gibbon, are almost totally arboreal, while
others, such as the macaques, are both tree dwelling and
terrestrial. Some primates, like baboons, are mostly
terrestrial. Owl monkeys and many of the prosimians
(Strepsirhines) are nocturnal while most other primates are
diurnal. Many nonhuman primates such as the macaques,
live in troops. Other species, such as the marmosets, live in
breeding pairs. Some species live in tree holes in the wild,
and benefit from nest boxes in captivity. Some species can
only survive in very limited tropical habitats while others
tolerate a wider range of temperatures. Some primates may
adapt to severe winter conditions. These species differences
have a major impact on the type of housing required to
adequately care for the animals.
The type of programutilizing the animals impacts the type
of primate housing selected. Animals in production colonies
may be housed in large enclosures capable of holding many
animals and their progeny. Some research protocols may
require that animals be housed individually or even in bio-
containment isolation to protect other animals, staff, and the
public at large from exposure to infectious or chemical
agents. Other protocols may require that animals be housed in
cages to allow close observation and access, but the experi-
mental design still allows housing in pairs or small social
groups throughout the experiment. The 2011Guide states that
“Single housing of social species should be the exception and
justified based on experimental requirements or veterinary-
related concerns about animal well-being.” The European
Union Directive (
European Parliament, 2009
) expresses
similar expectations.
Research requirements and financial resources dictate
the selection of the animal housing method. The location of
an institution and climate of the area affect the type of
housing utilized. An institution located in a densely
populated urban area may not have the option of housing
animals in outside enclosures. Local, state, or federal
regulations regarding environmental impact may affect the
type of facilities that can be used to house nonhuman
primates. Nonhuman primate housing methods may be
dictated by the experience of the institution with certain
types of cages. For other general considerations including
socialization and enrichment, see the table Components of
a Good Housing System in
Jennings et al. (2009)
.
management requirements. Different types of caging can
accommodate housing animals individually, in pairs, or
small groups. Frequent handling of animals may require
cages with movable backs so the inhabitants can be
restrained safely for injections or other procedures. Cages
with restraint devices may reduce personnel exposure to
some of the zoonotic diseases such as Macacine herpesvirus
1 (Cercopithacine herpesvirus 1, herpes B virus). Cages
available from commercial sources are sometimes custom
designed and constructed according to specifications
supplied by the purchaser. Existing designs may be modified
to suit special primate species requirements, research
program needs, or institutional requirements. Some insti-
tutions have the capability to fabricate or modify cages for
specialized requirements. Internet searches of primate
caging will locate a number of caging manufacturing
companies, and their features can be compared. Thoughtful
consideration beforehand can facilitate selection of the most
appropriate caging.
Several factors should be considered in the design and
selection of primary cage housing. Cages should promote
physical comfort of the animals being maintained and cage
height should be sufficient for animals to stand erect with
their feet on the floor (
National Research Council (Institute
for Laboratory Animal Research), 2011
). Cages should
allow for application of behavioral management aspects
such as socialization, training for procedures such as bio-
sample collection and agent administration, and features
for environmental enrichment to promote normal species
behavior. Caging design must address the prevention of
disease and undesired contact and fighting between adja-
cent animals, proper sanitization, ease of maintenance, and
ergonomic considerations for employee safety. Caging
must also meet the research and primate care requirements,
and meet the requirements of regulatory agencies.
Construction Materials
Nonhuman primate cages should be constructed of
nontoxic materials. They must be resistant to rust and
corrosion, withstand routine sanitation and maintenance
procedures, and safely contain the animals. Cages are
usually constructed of stainless steel or, less frequently,
aluminum. Galvanized metal was used in the past to
manufacture individual cages but is used less frequently
now. Newly developed plastic and composite materials
may provide useful alternatives for components of
cage construction or cage accessories. Although costly,
these newer materials can be thermoneutral and sound
attenuating.
Painted steel, still used in some countries, is the least
expensive material but should be avoided. The paint
covering the steel bars and sheet metal are easily picked off
by animals and may be eaten, thus posing a toxic hazard.
PRIMARY HOUSING DESIGN FOR
INDIVIDUALS, PAIRS, OR SMALL
GROUPS
General Considerations for Cage Design
and Construction
Nonhuman primates may be housed in cages to allow close
access for health observations or to fulfill investigative or
