In wildlife medicine, it is often necessary to chemically restrain animals to perform even the most basic procedure. This
is certainly true when one is working with members of the Order Carnivora, a large and diverse group of mammals consisting
of seven families (Canidae, Felidae, Ursidae, Procyonidae, Mustelidae, Viverridae, and Hyaenidae). It is, therefore, important
to be familiar with the variety of immobilizing agents and equipment used in this field, as well as to understand when to
use each of them. Because there is some overlap in the situations in which the various drugs and equipment may be used,
personal preference and familiarity play a large role in determining which types of immobilization agents and equipment are
used. Other factors involved in this decision include: facility design, the species involved, the attitude and behavioral
characteristics of the animal, and the physiologic or pathologic condition of the animal.
Considerations for choice of restraint methods include: human safety, animal safety, environmental factors, knowledge and
preference, and the preparation/planning involved.
Physical Restraint
Although physical restraint of native carnivores may be appropriate in some management and medical situations (and will be
influenced by the animal's type, temperament, size [generally ≤ 5 kg], and physical/pathologic condition), it does effect
patients in various physiologic and psychological ("stress") ways. In addition, physical restraint may precede an anesthetic
procedure, especially when the proper use of physical restraint can preclude the use of additional anesthetic agents. To
facilitate the physical restraint of nondomestic patients, therefore, one should have access to equipment such as protective
gloves, towels, hoop nets, snares, plastic tubes, and ideally, a squeeze cage.
Chemical Restraint
Most native carnivores, especially large (≥ 5 kg), wild, or fractious individuals, or those requiring extensive procedures
or surgical manipulation, require chemical restraint. In these cases, pre-immobilization planning is essential for successful
chemical immobilization. This involves having trained personnel, appropriate equipment, an equipment check-off list, a check-off
list to refer to during the procedure, emergency drug doses calculated, and a preanesthetic assessment of the patient (may
be visual/behavioral observations). Human and animal safety issues must also be addressed prior to the chemical restraint
of an animal.
Prior to anesthesia, the patient needs to be fasted for appropriate periods (generally 24-48 hours for large, 24 hours for
medium-sized, and 12 hours for small carnivores). Also, withhold water for 12 hours in large animals (unless dehydrated)
and 2 hours in smaller patients.
Premedication/sedation of animals may have value in some cases, but may be unnecessary in others. Some medications (i.e.,
diazepam) can be administered PO prior to a procedure, often with beneficial results; results, though can be highly variable.
To administer premedications parenterally, though, requires that an animal be handled or darted twice to achieve anesthesia.
In some cases, this can result in an excited animal at the wrong time, negating any potential benefit from a sedative. Frequently,
the anesthetic sparing effect of some sedatives can be retained by incorporating them with the anesthetic drugs (i.e., administering
the drugs simultaneously). Following induction, maintenance of the animal using gaseous anesthetics is often indicated.
Once anesthetized, it is important to monitor cardiopulmonary functions (i.e., pulse oximeter, Doppler blood flow monitor,
ECG, etc.) and temperature of the patient. Administering supportive care such as supplemental heat and fluid therapy to anesthetized
patients may be required. Recovery of an anesthetized patient should occur in an undisturbed, quiet, dimly lit, secure area
that is free from physical hazards. Animals are generally placed in lateral recumbency for recovery. Chemical reversal of
the anesthestic agent is generally desirable. Unfortunately, postanesthetic monitoring of native carnivores is generally
difficult.
