**WORKING WITH THE LABORATORY DOG**

Training for the Enhancement of Animal Welfare in Research

Videotape Script: June 2001

The use of dogs in research in the United States must comply with the
federal law known as the Animal Welfare Act, which is enforced by the
United States Department of Agriculture. Dogs used in research are also
covered by a Public Health Service policy and a publication entitled
*Guide for the Care and Use of Laboratory Animals*. Additional
information on the dog may be obtained from the book *Laboratory Animal
Management: Dogs* published by ILAR (eye'-lar), and from the Animal
Welfare Information Center at the National Agricultural Library.

In providing care for dogs, their social needs should be considered,
especially in the case of long-term housing. If research protocols
permit, dogs are often best housed in compatible pairs or small groups.
Dogs desire and benefit from interaction with people. Play, grooming,
and petting can provide very positive experiences for the dogs and their
care givers. Objects such as chew toys may also provide enrichment and
outlets for normal behavior. Check with your facility staff for toys
which are appropriate.

Dogs should have the opportunity for activity. This may be provided by
interaction with their care giver, by giving them access to play areas
or runs, or by being walked on a leash.

The ANIMAL WELFARE ACT requires that an exercise plan for dogs be put in
writing and be approved by the attending veterinarian and the
institutional animal care and use committee, or IACUC (eye'-ah-cook).

Typically, individually housed dogs must be exercised out of their cages
unless they are provided at least 2 times the minimum floor space
required by U-S-D-A regulations.

Group-housed dogs do not require exercise out of the cage if they are
provided with at least 100% of the required floor space for each animal.

The Animal Welfare Act requires that pain and distress be minimized in
laboratory animals. Researchers must consider alternatives to the use of
animals for procedures that may be painful. Such alternatives are
commonly known as the three R's:

-   Replacement of animals with nonliving systems or animals of lower
    phylogeny.

-   Reduction in the number of animals used.

-   And, refinement in the methods used on animals.

> Always assume that a procedure which causes pain or distress in humans
> may do so in other animals as well. Make refinements in your
> procedure, for example, by using analgesics and by reducing tissue
> trauma.

If animals do experience pain and distress, you must be able to
recognize the signs so that you can take corrective action. Watch for
changes in appearance, behavior, body weight, food and water intake and
clinical signs. Refer any abnormality to the attention of the veterinary
staff at your institution.

# Occupational Hazards

The barking produced by a room full of dogs may be loud enough to cause
injury to a person's hearing when exposed over a long period of time.
And even brief exposures can be a cause of stress in many people.

Therefore, when working in a dog room, consider the use of hearing
protection, such as headphones or foam inserts for your ears.

Although dogs can be very docile, they are capable of causing painful
and even severe injuries. Dogs may bite when fearful, in pain or if
provoked. They have powerful jaws, long canine teeth, and carnassial
teeth, which are premolars in the upper jaw that have sharp, slicing
edges for shearing flesh.

A dog's toe nails can inflict painful scratches, as when an animal is
struggling because it is either fearful or it is not well restrained.

Another occupational hazard is diseases that are communicable between
animals and humans. Such diseases are known as zoonoses
(zoh-ah-no'-sees). Diseases that are transmissable from dogs are listed
here.

For reasons of human safety, animal welfare and research integrity, it
is important to have a health surveillance program to ensure that dogs
obtained for research are free of these diseases. The program should
also ensure that the dogs have received the appropriate vaccinations and
parasite control.

Because of the potential risk for zoonotic disease, it is important to
ALWAYS wash your hands after handling any animal. Other protective
measures may be required by your institution.

# Methods of Identification

Dogs in an animal facility are required by U-S-D-A regulations to be
properly identified. Typical methods may be a uniquely numbered tag worn
on a collar, a tattoo on the inner side of the ear or an implanted
microchip.

**Anatomy of the Genitalia**

Determining gender is very straightforward in dogs. The male has a
conspicuous scrotum adjacent to the anus. The penis, sheathed in a
prepuce (pree'-puce), is located on the midline of the abdomen. Males
typically have a small amount of discharge, called smegma, in the
prepuce.

In the female, the vulva is close to the anus. Although not shown here,
the vulva will take on a swollen, reddened and moist appearance during
estrus. Also, estrus is signaled by the development of a hemorrhagic
discharge from the vulva.

**Approaching A Dog**

When first approaching a dog, take a moment to assess how the dog is
reacting to you, and adjust your manner accordingly. Some dogs will
eagerly approach you, but others may be fearful and withdraw to the back
of the cage. Take care not to be bitten in these situations. Some
individuals who are afraid will bite defensively. These are often
referred to as "fear biters". Be careful to use nonthreatening postures
and movements, such as crouching low to place your body on the same
level as the dog, and using a soft but high-pitched reassuring tone of
voice. If a dog appears aggressive, stop and get assistance from
experienced staff.

**Transportation**

Many dogs can be easily lead short distances with a leash, as from
housing areas to procedure rooms. Transport cages can be used for dogs
that will not follow on a leash, or when dogs will be transported long
distances.

Lock the wheels to prevent the cage from rolling when placing or
removing a dog.

To lift a dog, circle your arms around the trunk. Place one arm around
the chest and one behind the rear limbs. To prevent injury to your back,
lift with your legs, not your back.

For most procedures it is best to move the dog onto an examination
table. Make sure ALL four legs are securely on the table. Position the
dog in a recumbent pose and prevent him from standing.

# Restraint

A simple rule for physically restraining animals is to use the least
amount of restraint necessary to accomplish the procedure safely.

However, consideration must be given to protecting both the animal and
personnel. Since each dog has a unique personality, it is helpful to
understand the normal behavior patterns when evaluating the best means
for handling and restraint. Don't forget that for some dogs, the most
humane way to restrain them may be to administer tranquilizers,
sedatives, or anesthetics before any handling.

Here are some things to avoid: Don't distress the animal by applying
excessive restraint. To prevent the dog from injuring himself, never
leave an animal alone on a table. Avoid making loud noises or fast
movements that may startle the dog.

# Restraint in Sternal Recumbency

The basic restraint position used for many procedures is sternal
(ster'-nil) recumbency, in which the dog's sternum, or breastbone, lies
in contact with the table.

One arm is placed under the dog's chin to control the head, while the
other arm is placed over his back to prevent him from standing up. If
necessary, the dog's head can be stabilized against your neck to provide
better head control. This restraint position is useful for access to the
cephalic and jugular veins.

Another restraint position is LATERAL RECUMBENCY, where one flank of the
dog is in contact with the table. Holding onto the downward limbs
prevents the dog from sitting up from this position. Note how a finger
is inserted between the forelegs to prevent them from being pressed
together too tightly. At the rear limb, you can also place your hand on
the knee to stabilize the leg for venous procedures.

These methods of restraint are appropriate for most situations because
dogs are generally cooperative. However, if an animal is fractious,
other methods may be necessary and you should get help from experienced
staff to avoid injurying yourself or stressing the animal.

The use of a muzzle will usually cause stress to a dog, and they are not
needed for most individuals. But a muzzle should be considered any time
a dog's temperament or past behavior suggests that a bite is likely. A
muzzle must be fitted snugly so that it protects against bites, but at
the same time it must be comfortable for the dog.

Muzzles made from leather or synthetic fabrics are available in many
sizes. Use one that is appropriate to the size of the dog.

A good-fitting muzzle should slip easily over the dog's snout but it
should also fit snugly without being too tight. Adjust the size of the
strap to fit firmly but comfortably.

A quick muzzle can be fashioned out of a long strip of gauze. This can
be useful in a situation where you fear the dog may bite.

First, make a large loop with a loose knot in a single throw. \[freeze
#1\] A large loop allows you to keep your hands at a safe distance until
the muzzle is tied. Slowly and gently, slip it over the dog's jaws.
Secure the knot on top of his nose, \[freeze #2\] and then tie another
loop with a single-throw knot below the mouth. \[pause\] Finally, tie it
behind the head, with a bow. Although all knots must be secured, the
muzzle should not be so tight anywhere as to pinch the skin. This would
be painful and would cause the dog to struggle.

To remove the muzzle, untie it at the back, and again keeping your hands
away from the dog, slowly pull the gauze strip towards you. Note how the
steady, gentle pull loosened the knots around his jaws without hurting
him. That is why only single-throw knots should be used.

The dog has five toe nails on the front feet and four or five toe nails
on the rear feet. Note the dew claw, which is equivalent to the human
thumb nail and is located just below the carpus (car'-pis). These toe
nails are a proper length. But when too long, they can cause a
malpositioning of the toes, or become caught in caging. Long toe nails
also present a greater risk of scratch injuries to people.

A dog's nails should be routinely trimmed. There are two types of nail
trimmers, the guillotine type and the scissor type. Both are safe and
effective when used properly.

To trim a nail, first identify the quick. This is the sensitive tissue
at the base of toenails in all species, including humans. You do not
want to cut the quick because it would be painful to the dog, and would
bleed profusely.

Position the clippers carefully to avoid cutting the quick. If the nail
is unpigmented, you can see it as a triangular area towards the base of
the nail. If the nail is pigmented, where you cannot see the quick, trim
on the thin and curved tip of the nail.

The scissor type trimmer has a nail guard behind the blades to prevent
cutting too much of the nail. And on the front feet, don't forget to
trim the dew claw.

**Routine Care Procedures -- Clipping Fur**

For many procedures, the first step is to clip the fur. Because the
dog's skin is sensitive, it is important to use the clipper correctly to
avoid scratching or burning the skin. Position the clipper with the
blade laid flat on the skin to allow the teeth to work best in cutting
the hair. And, clip against the direction of the fur. Where fur grows in
multiple directions, you should reposition the clipper for each track of
growth. Never angle the clipper to drag the blade across the skin, which
will cause scratching. When clipping for a long period of time, feel the
blade with your hand to ensure that it is not getting hot. Also, avoid
going over the same spot repeatedly, which may abrade the skin. With
care, you can prevent causing a rash commonly called "clipper burn". And
last, avoid rushing because working too fast will increase the chance of
injury to the dog.

**Oral Administrations**

Whenever possible, embedding medication in a ball of moist food is an
easy and effective method of administration. Because dogs generally
swallow without chewing their food, they do not notice the presence of a
pill and swallow it quickly. This is also an opportunity to provide the
dog with a special treat and some friendly attention.

When it is necessary to administer a pill by hand, place it between your
thumb and index finger. Your third finger is used to open the animal's
lower jaw. With your other hand lift the upper jaw to open the mouth.
Press the lips inward at the space behind the canines, but be careful
not to pinch the lips against the teeth. The pill must be administered
far back in the throat, near the base of the tongue, where it will be
swallowed by reflex action. Otherwise, the tongue can easily push the
pill out of the mouth.

To facilitate swallowing, hold the jaws closed and massage the throat.

**The Pill Gun**

A device known as a pill gun offers an advantage of easily delivering a
pill to the back of the throat. Load the pill in the tip, which is made
of a soft rubber so as not injure the throat.

Insert the pill gun into the side of the mouth, in the space just behind
the canine teeth. Once it is advanced to the back of the throat, press
the plunger to release the pill. Again, if delivered far back in the
mouth, the pill will be swallowed by reflex action. But if the pill ends
up more forward in the mouth, hold the dog's jaw closed and massage the
throat.

**Oral liquid administration**

When liquids in volumes up to twenty ccs (see-sees) must be
administered, it is best to use a syringe. Oral gavage with an
orogastric tube should be considered for the administration of larger
volumes. This will be demonstrated in tape 2. To administer by syringe,
allow the dog to maintain a position comfortable for his head. A slight
upward tilt will help fluids drain towards the throat. Administer at a
rate comfortable for swallowing. If too fast, the dog may become
frightened, or the material may spill out of the animal's mouth.

**Use of the elizabethan collar**

In some instances, an Elizabethan collar may be used to prevent a dog
from traumatizing an area of his head or body, such as the site of a
surgical incision.

It should be sized to extend past the animal's nose, which will prevent
licking or chewing of areas on his body and scratching on his head. The
edge around the neck should be padded.

\[Pause until 21:26:09\] The collar should be fitted to the neck to
allow just enough space to pass your fingers through the opening. Any
tighter would be uncomfortable for the dog.

Dogs will quickly adjust to wearing an Elizabethan collar. It is very
important, however, to determine that it does not interfere with the
animal's access to food and water. And it should be removed when no
longer needed.

# Injections and Blood Collection

For injections and blood collection, the sizes of needles used are
commonly in the range of 20 to 25 gauge. To minimize the pain of the
procedure, always use the smallest size of needle that is appropriate
for the procedure.

**Blood Collection**

For small amounts of blood, such as one to ten cc (see-see), the
cephalic (sa-fal'-ic) vein is a good site for blood collection. Position
the dog in sternal recumbency. The elbow should be braced to prevent the
dog from moving the limb during the procedure. The assistant's thumb is
placed over the forelimb, close to the elbow, to distend the vein.
Occlusion is always applied between the site of venipuncture and the
heart, in which direction the blood is flowing. Because veins are
thin-walled and easily collapsed, the occluding pressure should be
gentle. At the same time, it is helpful to roll the vein laterally,
stretching and stabilizing the vein for venipuncture.

Make sure that the distended vein is visible. If necessary, reposition
the dog or adjust the occlusion to enhance your view of the vein.

Alcohol is swabbed to cleanse the area and to improve the vein's
visibility. Before inserting the needle, remember to break the adhesive
seal in the syringe barrel to prevent a jarring motion that could
traumatize the vein wall.

Direct the needle bevel up, or, away from the vein. You may insert the
needle into the vein in a single movement, or in stages -- that is, by
first introducing the needle under the skin parallel to the vein, and
then repositioning the needle to enter the vein. Avoid attempting to
draw blood too quickly because excess negative pressure can collapse a
small vein, making blood collection difficult, and it can injure the
blood cells, resulting in hemolysis. Once blood sampling is completed,
it is critical to release the occlusion of the vein before the needle is
pulled out. Otherwise, the pressure will force blood to leak out through
the puncture site into the surrounding tissues, which will cause
bruising and soreness. As the needle is withdrawn, apply pressure to the
puncture site for a few minutes until bleeding stops.

The jugular veins, located on the left and right sides of the neck,
allow for a rapid collection of large volumes of blood. A maximum amount
of one percent of the animal's body weight may be collected at one time,
followed by a two-week rest period from further blood collection.

Note how occlusion at the base of the neck makes the jugular vein stand
out.

Despite its large size, the jugular vein may be difficult to puncture
because it often rolls away from the needle, due to its loose attachment
to subcutaneous tissues. Your hand at the base of the neck will help
stabilize it, but you may also have to use a jabbing motion to insert
the needle into the vein. \[Pause until needle being withdrawn. Can cut
the following paragraph if the motion segment is cut...to avoid
repetitiveness.\]

When withdrawing the needle, apply pressure for one minute to the
puncture site in the vein.

Low on the hind limb, the lateral saphenous (sa'-fin-iss) vein,
sometimes called the lateral recurrent metatarsal (metta-tar'-sil) vein,
may be used to collect small volumes of blood. This vein, however, is
not often used. Because of its smaller size, and its fragility, it is
prone to forming a hematoma.

With the dog on his side, brace one hand on the knee of his uppermost
rear leg, to both control movement and to distend the vein.

Hold the front limbs by the carpus (car'-pis). Insert one or more of
your fingers between the front legs to avoid pinching them together.

Note that the vein crosses the lateral side of the rear leg, diagonally,
just above the tarsus (tar'-sis).

To minimize the risk of causing a hematoma., it is best to insert the
needle under the skin and then to reposition it to enter the vein.

# Intramuscular Injection

Intramuscular injections are most commonly administered in the anterior
muscles of the thigh and along the lumbar spine. There are no major
vessels or nerves in either site, so that both routes are very safe for
the animal. Volumes of up to 2 to 5 cc (see-see), depending on the size
of the dog, may be injected in any one site. For these demonstrations,
the limbs are shaved to expose the anatomical landmarks.

For the anterior thigh injections, grasp the quadriceps muscle mass and
use your fingertips to locate the femur. Direct the needle perpendicular
to the leg and insert it into the center of the muscle mass. Aspirate to
make sure the needle has not entered a vessel, and then inject slowly.
Finally, massage the area to disperse the material and prevent leakage
back to the skin.

The epaxial (ep-AX-iel) muscles along the lumbar spine may be used as
well. This site also lacks major vessels and nerves that could be harmed
by an injection. Place your hand on the animal's back, fingers pointing
towards the tail. Lay your index finger on the ridge of the spine. Rest
your little finger against the last rib. Gently press your other fingers
into the abdomen to feel the edge of the epaxial muscles. Direct the
needle perpendicular to the body and insert it into the center of this
muscle mass, midway between the spine and the muscle edge. Aspirate,
inject slowly, and then massage the area.

Intramuscular injections may also be made in the caudal thigh. This site
does have large vessels and nerves, particularly the sciatic, which may
be injured by injections made incorrectly. It is essential that the
needle is directed away from the femur (fee'-mer) to avoid these
structures. Otherwise, the needle may enter a vessel, resulting in an
intravascular injection, or it may traumatize a nerve, resulting in
paralysis.

Note the position of the sciatic (sigh-A'-tic) nerve on the lateral
aspect, and the position of the femoral (fem'-er-il) nerve and vessels
on the medial aspect. The figures also show the CORRECT orientation of
the needle, directed caudally (cod'-illy) AWAY from the femur.

Grasp the muscle mass posterior to the femur and insert the needle in a
caudal (cod'-il) direction, away from the bone. Aspirate, inject slowly
and massage the area when finished.

**Subcutaneous Injection**

Dogs have a loose attachment of skin to underlying muscles, which allows
injections to be made subcutaneously. Injections are commonly made over
the trunk between the shoulders, where the skin is loosest and least
sensitive to the momentary pain of injection.

Raise a fold of skin, like a tent, and direct the needle into the base.

Aspirate to ensure that the needle has not entered a vessel, and then
inject.

Finally, massage the area to disperse the material and to prevent
leakage back to the skin.

A common ERROR is to insert the needle too high in the skin fold, near
the peak of the tent. Note how the needle can penetrate through the
opposite side of the skin fold, resulting in the loss of the injection
material onto the skin surface. This mistake can easily be overlooked in
animals with long fur or when a small volume is injected.

**Use of sedatives and anesthetics in the dog**

There are many choices of these agents available for use in the dog.
Refer to a text on laboratory animal medicine for recommended drugs and
doses. However, because of complexities in drug interactions and effects
on the animal, it is essential that you consult with a veterinarian to
determine a dosage regimen that is appropriate for the length and type
of the procedure and the need for analgesia.

When used alone, sedatives provide a tranquilizing effect which assists
in handling an animal. Some agents also have an analgesic effect. None
of these agents can be used alone for painful procedures, such as
surgery. However, they are useful adjuncts to general anesthetics to
achieve a balanced anesthesia.

The common anesthetics are very different classes of drugs, with very
different properties.

Gaseous anesthetics offer good analgesia. Because gas is delivered by a
dialable vaporizer, the duration of anesthesia can be matched to the
length of a procedure.

Ketamine, known as a dissociative anesthetic, provides mimimal
analgesia. And when used alone in the dog, it can cause seizures.
Therefore, it must be combined with other agents to not only prevent
seizuring, but also to provide sedation and analgesia.

Pentobarbital, though still used, has disadvantages of a low safety
margin, hepatic enzyme induction, prolonged and rough anesthetic
recovery, and regulatory restrictions as a controlled substance.

Analgesic agents are primarily used for pain relief. In general, they
should be used for routine post-operative care unless otherwise
scientifically justified. There are two common classes of drugs -- the
opioids (oh'-pee-oids) and the nonsteroidal (non'-ster-oid'-il)
anti-inflammatory drugs. The opioids may also be used in combination
with general anesthetics for achieving a balanced anesthesia. Of those
listed, buprenorphine has the longest duration of action and is
therefore preferred in post-operative care.

**Euthanasia**

Animals should be euthanized when killed for any purpose including
research. Euthanasia may be defined as a gentle death that is free of
pain and distress. In addition to using an appropriate method, proper
administration of euthanasia includes the use of humane handling and
restraint of the animal in the procedure leading up to its death and if
possible rapidly rendering the animal unconscious before the moment of
its death. It is important to consult with a veterinarian on selecting a
method of euthanasia and how to conduct it properly. The method must
take into account the following considerations:

one - humaneness for the animals;

two - aesthetics for the operator and observers;

three -- sensitivity to the emotional attachment by others to the
animal.

four - safety for the operator to perform; and

five - training of the operator in the method used, in the proper
handling of the animals to be euthanized, and in the concepts of
euthanasia;

A preferred method for all species, whenever possible, is the use of
anesthetic agents, such as the barbiturates, or a specific euthanasia
formulation.

For more information, refer to the Report of the American Veterinary
Medical Association's Panel on Euthanasia and guidelines from the
Universities Federation for Animal Welfare in the United Kingdom.

This concludes the first part of our series on the dog. Refer to tape 2
for training in catheterization of peripheral veins, injection of the
lingual vein, determination of a pulse, collection of arterial blood,
the monitoring of vital signs, endotracheal intubation, orogastric
intubation and urethral catheterization in the male and female dog.