Front Cover

Title: Raising laboratory animals and other small stock
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00049915/00001
 Material Information
Title: Raising laboratory animals and other small stock
Physical Description: Book
Creator: Arrington, Lewis Robert,
Publisher: Florida Agricultural Extension Service,
Publication Date: 1968
Copyright Date: 1968
 Record Information
Bibliographic ID: UF00049915
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: 003436213 - Electronic_Aleph
62367790 - Electronic_OCLC

Table of Contents
    Front Cover
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
Full Text
:IRCULAR 326 JUNE 1968
Raising Laboratory Animals
and other Small Stock

)r. L. R.






The term "laboratory animals" is used to iden-
tify the several species of small animals used in
research, and "small stock" represents a larger
group to include those species kept as pets and the
fur bearing animals. Considered as a whole, the
largest numbers of these animals which are pro-
duced are used in research. The numbers raised
for this purpose have increased in recent years, and
it has been estimated that approximately 30 million
mice, 12 million rats, one million guinea pigs and
somewhat smaller numbers of hamsters, rabbits,
and others are used annually in this country. Var-
ious species of these animals have been used in
high school projects and other youth projects and
for certain demonstrations in the lower school
grades. Rabbits are somewhat unique in that they
are widely used for meat as well as in research,
as pets, and their skins or fur have other limited
The purpose of this publication is to present gen-
eral information on the production, care and mar-
keting of the more common species of laboratory

Table 1. Characteristics ol

Mice Rats
Mature size, gms.
Male 20-40 300-400
Female 18-35 250-300
Birth weight, gms. 1-1.5 5-6
Weaning weight, gms. 10-12 35-45
Weaning age, days 21 21
Breeding age 50-60 90-100
days days
Estrus cycle, days 4-5 4-5
Gestation period, days 19-21 21-22
Lactation period, days 21 21
Number young per litter 1-18 1-14
Average 11 10
*Figures are average or the expected range.
:":Data for rabbits are for the New Zealand white breed.

animals. Persons interested in commercial produc-
tion for research or sale for other purposes should
obtain more detailed information for the particu-
lar animals to be produced. Recent Federal Legisla-
tion has established certain standards and require-
ments for laboratory animal welfare, and those
marketing animals should become familiar with
this law.

A number of different species of small animals
make up the group of so-called laboratory animals,
the more common ones being mice, rats, rabbits,
guinea pigs, hamsters, gerbils, dogs, cats and
monkeys. Several of these were developed for lab-
oratory use through generations of selected breed-
ing. Many highly inbred strains of mice and rats
with special characteristics useful in research are
now available. The gerbil is a relatively new intro-
duction to laboratory use. It is smaller than the rat,
but somewhat similar and is sometimes referred to
as the desert rat. It consumes very little water and
excretes a small amount of urine. Gerbils are easily
handled and maintained and are becoming popu-
lar as small pets. Guinea pigs, also known as cavies,

Common Laboratory Animals*
Rabbits* pigs Hamsters Gerbils

9-12 lbs. 900-1200 85-110 80-90
10-14 Ibs. 800-1100 95-120 70-80
100 75-100 2-2.5 2.5-3
1600 250 35-40 15-17
45-55 10-15 21 21-24
6-7 90-100 50-60 70-80
Mo. days days days
15-16*** 16-19 4 -t
31-32 60-70 16 23-25
45-55 10-15 21 21-24
1-16 1-6 1-12 1-12
8 3 10 5
Ovulation is induced in the female rabbit and they will
breed on most of the days of the estrus cycle.
tEstrus cycle of the gerbil is unknown, but is expected to
be about 4 days.

are the animals without a tail, smaller than rabbits
and have been used for many years as laboratory
animals. Hamsters are unique among the labora-
tory species in that they have cheek pouches and
at temperatures below 480F they may hibernate.
Hamsters will hide or store feed in the pouches and
occasionally the mother may be observed to hide
her young in the pouches.
Additional specific characteristics of the labora-
tory animals are recorded in Table 1. The figures
are shown as averages or as a range when the
range may be more useful. Additional information
on breeding is presented in a subsequent section.

Cages and the buildings in which small animals
are kept do not provide an environment which is
the same as their natural habitat, so housing should
be planned to provide comfort as well as sanitary
conditions. In large commercial production and in
research laboratories, mechanical control of the
environment is provided. When small numbers are
kept as pets or for non-research purposes such con-
trol may not be required or possible, but housing
must provide protection from cold, heat, excessive
moisture and provide fresh air. Considering the
small animals as a group, a temperature of 740F
is suitable and should not fluctuate greatly. They
may be kept at a somewhat higher or lower temp-
erature, but once the temperature is selected, it
should be held as constant as possible, preferably
20F. Rooms housing small animals should pro-
vide for fresh air, but drafts should be avoided.
When the temperature falls below 650F some bed-
ding material in which animals may seek protec-
tion should be provided.
Metal cages are desirable since most of these
animals are rodents and may soon eat through
wooden parts of cages. Suitable cages for each
species may be purchased from various supply
houses or they may be constructed from hardware
cloth. Figure 1 shows several types of cages housing
rats in an experimental laboratory. Sufficient space

Figure 1. Some types of cages, feed and water devices used
for small laboratory animals. Note water bottles with delivery
tube, and cages with raised wire floor being used for rats.
Other water and feed cups of different sizes are shown.

must be provided for comfort and some activity.
Rats, for example, should have floor space equal
to approximately 40 sq. in. per rat when housed in
groups and a larger space when housed individu-
ally. One rabbit should have at least 4 to 5 sq. ft.
of floor space per animal. Typical rabbit cages are
shown in Figure 2.
For better sanitation and ease of cleaning, some
animals may be housed in cages with raised wire
floors. These are usually made of hardware cloth
or welded wire of a size that provides reasonable
comfort, but permits excreta to pass through the
floor to a pan underneath. For adult rats the floor
screen should be 1/2 inch mesh and for adult rab-
bits should be 5/8 inch mesh or 1/2 x 1 inch weld-
ed wire. Smaller wire should be used for the smaller
Guinea pigs, mice and gerbils generally are not
housed very satisfactorily on wire, so they are more
commonly maintained in cages with solid floors
and bedding (Figure 3). Bedding should be sup-
plied as clean sawdust or shavings, ground corn
cobs, shredded paper or other clean absorbent ma-
terial. Cages with raised floors should be provided
with absorbent paper or litter under each cage.

Guinea pigs, rats, mice and gerbils may normally
be housed in groups, provided adequate space is
provided. Hamsters and rabbits, unless raised to-
gether are very likely to fight excessively and they
are normally housed individually except when a
constant group has been established.

Diets for most of the common laboratory animals
are now available from feed manufacturers. These
are pelleted, easy to feed and provide a complete
diet which generally requires no supplementation.
It might be noted that, when a feed for a particu-
lar species is not available, certain substitutions
may be made. Mice, rats, hamsters and gerbils, for

Figure 2. Typical cages for housing rabbits in an experimental

example, have similar dietary requirements and
may be fed a rat or mouse diet. If none of these is
available, a dry dog food could be fed for a short
time. Rabbits and guinea pigs have somewhat simi-
lar dietary requirements and a feed for one of these
could be fed to the other for a reasonable time.
Guinea pigs, however, require a dietary source of
vitamin C. If adequate vitamin C is not present in
the diet it should be supplied as fresh cabbage or
other greens once or twice per week or the vitamin
may be added to the water. A mixture of grains
might be fed to some species for short periods, but

it is difficult to provide a balanced diet in this way
and the prepared commercial feeds are much more
Small animals may be provided the diets free-
choice and one daily feeding of the dry feed is
usually adequate. The feed, however, should always
be fresh and not be allowed to become contami-
nated with water, urine, feces or insects. Fresh
clean water should be available at all times. Several
types of water and feeding devices are shown in
Figure 1.


The production and care of laboratory animals
requires that they be handled frequently. Most of
them become accustomed quickly to handling when
it is done properly and usually no problems are
encountered. Unhandled animals are obviously
excitable, and mice, rats and hamsters may give
painful bites. The handler should be patient, con-
sistent in the method used and avoid fear and
Mice are easily picked up by the tail, which
should be grasped near the body. When necessary
to restrain the mouse, it may be held by the loose
skin over neck and shoulders. Rats are normally
held by the whole hand-palm over back and side,
fingers around chest with forefinger in front of the
fore legs. Hamsters and gerbils may be handled
with the whole hand or by the loose skin on shoul-
ders and neck. Rabbits are lifted by the skin over
shoulders-never the ears-and lower part of the
body should be supported with the other hand.
Guinea pigs are usually handled in a manner simi-
lar to that for rats, but both hands may be required.


General breeding characteristics of the common
species of laboratory animals are indicated in
Table 1. Mice, rats and guinea pigs may be bred
by placing one or more males with a group of fe-
males. This method of colony or polygamous

breeding does not permit identification of parent-
age and the timing of conception is more difficult,
but it has the advantage of breeding a number of
animals in a small number of cages. Individual
female hamsters and rabbits should be transferred
to the male's cage for mating. If the female ham-
ster is in estrus she should remain with the male for
15 to 30 minutes. Female rabbits will accept service
on most of the days of the estrus cycle and mating
usually takes place in a short time when the female
is introduced to the male's cage. The female ham-
ster and rabbit should be returned to their cages
after mating, otherwise fighting may occur. Some
species exhibit a post-partum estrus within a few
hours after the birth of their young and may breed
at this time if they are in cages with males. Gerbils
mate for life and should be paired before breeding
Several days prior to the time of parturition
(birth of young), the females which may have been
housed in groups or on wire floors should be trans-
ferred to an individual cage with a solid floor and
bedding. Although mice, rats and guinea pigs can
care for young in cages with other animals, it is

Figure 3. Solid bottom cages with bedding used for housing
mice and guinea pigs.

more desirable that they be provided a single cage.
Rabbits should be provided with a nesting box con-
taining hay, straw or some bedding material several
days before parturition.
Dead or injured young should be removed as
soon as possible after birth, otherwise the female
may start cannibalism. If a female with young
should die or should produce more young than may
be nursed properly, it is often possible to transfer
(foster) the young or a portion of the litter to
another lactating female. Females of most species
will accept young from another if they are trans-
ferred within a few days after birth and young are
the same approximate age. It is often helpful to
introduce some scent or odor into the cage which
will mask the smell of the young transferred and
the female will less likely reject the fostered young.

Cages, feeders, waterers and all other equipment
coming in contact with animals should be kept
clean and sanitary. They should be washed period-
ically in hot water containing a good washing com-
pound. In commercial operations, in research or
other situations where animals are maintained for
long periods, cages and other equipment should
be sterilized with heat or sanitized with a disinfect-
ant solution. The frequency of this cleaning may
depend on several factors, but normally clean cages,
feeders, etc., should be provided at least once
weekly. Bedding in cages and litter under raised
wire floors must also be changed at intervals of
about one to five days as required to minimize odors
and provide better sanitary conditions. Animals,
feeds and equipment should be protected from
other animals, insects, smoke, fumes, etc. Any
animal which appears sick should be isolated from
the others and treated or destroyed.

Fairly extensive markets exist for most of the
laboratory animals, yet satisfactory and profitable

disposition of small animals may be one of the ma-
jor problems unless definite market outlets are
determined and established before production is
started. The market for research animals is a rath-
er specialized one, and unless animals are pro-
duced to meet the specifications required, they
may not be suitable as research animals. This
means that the producer should determine from
the laboratory or research center what specifica-
tions should be met. At present there is a substan-
tial market for quality laboratory animals of many
species and those producers prepared to meet the
specifications should find a ready market.
Rabbits which are sold for meat are usually sold
to a processor who slaughters and sells to wholesale
and retail outlets. Since some of these small ani-
mals are kept as pets, they may often be marketed
through pet stores.
Information on the production and marketing of
fur bearing animals in this state is very limited and
has not been included in this report. A word of
caution about beginning production of these ani-
mals should, however, be stated. Occasionally ad-
vertisements and claims are seen which indicate
very high profits which may be expected with some
fur animals. Considering the limited information
available, the problem of production and breeding
and the likelihood of a fluctating market demand,
one should move very cautiously before investing
money and time in production of fur bearing

Cooperative Extension Work in
Agriculture and Home Economics
(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida
United States Department of Agriculture, Cooperating
M. O. Watkins, Director

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