Regional anesthesia provides muscle relaxation as well as postoperative pain relief since its numbing effects can last 8 to 12 hours, depending upon the dose. Some veterinary procedures need to be performed with the animal under general anesthesia (for example: dentistry, surgery, and some diagnostic imaging).
Anesthesia-related deaths are rare, though, and while complications can occur, the veterinarian and his/her team take all the necessary precautions to ensure that the animal is safe and can handle anesthesia. However, veterinarians face limitations and challenges that are oftentimes not encountered in the practice of adult human medicine.
First, since wildlife and zoo animals are nonverbal, they cannot communicate their degree of pain or the efficacy of an analgesic technique that has been employed. Veterinary medical professionals must rely on various assessment tools to estimate the degree of pain.
There are wide variations in exotic species’ anatomy, physiology, and the pharmacokinetics of local anesthetics that must be taken into consideration prior to safely performing regional anesthesia. Felines have increased sensitivity to local anesthetics when compared with other species, necessitating much lower maximum doses be used.
“A general anesthetic event for a horse, for example, requires specialized equipment and carries a much higher risk of complications such as long-bone fractures, myopathy, and neuropathy simply based on sheer size. Equine anesthetic mortality is reported to be 10- to 20-fold greater than for dogs and cats.” 5 For these reasons, large animal surgical procedures are typically performed under sedation with regional anesthesia.
5 In the zoo setting, input from the animal’s primary caregivers, the zookeepers who are attuned to subtle changes in behavior, are often the only clue to discomfort in some species. The zoo veterinarian is frequently called upon to plan and administer analgesia for a wide range of species.
He or she must not only recognize and interpret signs of discomfort in these species, but must also determine and implement effective analgesic regimens that accommodate patient and caregiver safety. “Many zoo animals are large, dangerous animals that cannot be approached directly without a barrier or immobilization.
However, while that approach may be necessary for a large carnivore such as a lion or tiger, the veterinarian also must be ready to treat something as small as a poison dart frog.” 1 1 Pharmacokinetic studies and analgesia efficacy experiments are rare in the field of zoo medicine.
One very important addition to the arsenal of treatment strategies that has revolutionized the approach to zoo veterinary care is the use of behavioral training to facilitate treatment.” 3 6 Perry R, Moore D, Surreal E. Globe penetration in a cat following maxillary nerve block for dental surgery.
Procedural sedation combined with loco regional anesthesia for orthopedic surgery of the pelvic limb in 10 dogs: case series. Unlike other veterinary compounding pharmacies, Bergen focuses on drugs that are difficult to find or are no longer available due to manufacturer discontinuance or have yet to be offered commercially for veterinary applications, but which still serve a critical need for our customers.
Our pharmacists are also encouraged to develop strong working relationships with our veterinarians in order to better care for veterinary patients. Such relationships foster an ever-increasing knowledge base upon which pharmacists and veterinarians can draw, making both significantly more effective in their professional roles.
Bergen Pharmaceuticals compounded veterinary preparations are not intended for use in food and food-producing animals. Bergen Pharmaceuticals, LLC does not recommend, endorse or make any representation about the efficacy, appropriateness or suitability of any specific dosing, products, procedures, treatments, services, opinions, veterinary care providers or other information that may be contained in this blog post.
For example, the animals may have problems to solve in order to get their food, rather than it just being dropped in front of them. You don't just put a grizzly bear behind a flimsy fence and drug it.
The enclosure will have strong metal fencing or thick, reinforced glass, an overhang or roof if the animals are climbers or high jumpers, fencing which extends below ground if the animals are diggers, etc. They don't take to tranquilizers well, and any reputable zoo will not drug them unless it is the last resort.
The animals can easily have health problems from the drugs, or even die. Even though wild...most animals in zoos come from breeding programs and have been raised in captivity...now although that doesn't mean they are tamed or domesticated.those environments are all they know and are usually quite comfortable with their exhibits... I used to work for the Houston Zoo and the only time we sedated any animals was if it needed to be examed or going to the vet., even when cleaning exhibits if we could get the animal into a holding cage without sedation we did.
Because many zoo animals, especially prey species, instinctively conceal overt signs of illness until the disease process is well advanced, it is necessary to make keepers aware of the significance of what may seem to be trivial changes. Once a diagnosis is made, the treatment of zoo animals is similar to that of domestic species except in the method of drug administration and restraint.
Unless medical conditions dictate otherwise, it is often preferable to leave an animal under treatment at its home exhibit where it can maintain contact with its conspecifics and keepers. This can also prevent disruptions in social hierarchies, which may cause difficulties with reintroductions to an established group.
Through positive reinforcement, amphibians, reptiles, birds, and mammals in zoo settings have been trained to perform behaviors on command that facilitate accomplishment of various management or medical procedures. Management behaviors include shifting on and off exhibit, onto scales, and into restraint devices or shipping containers.
Procedures such as venipuncture from the ear, foot trimming, reproductive evaluation, artificial insemination, and trunk washes are routinely performed using protected contact. Restraint devices (squeeze cages) or chute systems are frequently used for species that are large, dangerous, or difficult to handle.
Many procedures can be performed on anesthetized animals so confined, including limited physical examinations, tuberculin testing, administration of injections or anesthetics, collection of blood samples, trimming malformed claws or overgrown hooves, and application of topical medications. Although the dimensions and construction of these devices vary, some operate by movement of one wall to restrain the animal against the other.
Exhibits should contain nest boxes or restraint pens equipped with doors that operate remotely to confine the animal. From these areas, the animal can be transferred to a restraint device, anesthetic chamber, or shipping container.
Personnel participating in capture or restraint procedures must understand their role and be aware of the behavioral characteristics and physical abilities of animals. Heavy gloves protect handlers from teeth and claws when animals are manually held after capture.
The fundamental diagnostic technique is a good history and thorough visual and physical examination (often requiring anesthesia). Ease of sample collection for laboratory testing (CBC, biochemical profile, serology, cytology); fecal examination for parasites; urine for urinalysis; and aerobic, anaerobic, fungal, and viral culture depends on species anatomic differences.
Antibiotic, antifungal, and analgesic treatments, as well as anesthetic dosages, are becoming less empirical because of increasing species-specific knowledge resulting from pharmacokinetics studies in zoo species. When using a drug on a group of animals for the first time, it is often wise to initially administer it to just one or two individuals.
Oral antibiotics in hoof stock and other species can disrupt normal bacterial flora and lead to GI problems. Oral sedative or anesthetic administration can result in variable onset, duration, and depth of effect because of inadequate consumption or delayed absorption.
Remote I'm injections may be made by firing a projectile syringe from a dart gun. Other less traumatic methods of I'm injection, over shorter distance, include syringe poles or blow guns.
IV therapy is generally restricted to anesthetized animals or those maintained in restraint devices or small enclosures for the duration of treatment. Many procedures routinely accomplished on domestic animals with minimal restraint require anesthesia of zoo logic species for the welfare and safety of both zoo animals and personnel.
Before anesthesia of a zoo animal, the veterinarian should be familiar with the species and choice of anesthetic agent. Consultation with someone knowledgeable in the field is advised, because there are large differences in effective drugs and dosages in the diversity of species in a zoo logic practice.
An excited animal usually requires more drug and, once anesthetized, has a greater tendency to develop capture myopathy secondary to hyperthermia, respiratory depression, and acidosis. Attention must be paid at all times to appropriate positioning and padding of anesthetized animals and extremes of environmental conditions to prevent secondary complications.
Magazine, deoxidize, or medetomidine ( 2 -adrenoreceptor agonists) used alone produce adequate sedation in some ungulates, mainly bodies, to allow some manipulative procedures. 2 -Agonists should not be used as the sole anesthetic agent in dangerous carnivores, because the animals may appear sedated but can respond aggressively when stimulated.
Peripheral vasoconstriction caused by these agents alone or in combination with other drugs can lead to significant hypertension, so blood pressure should be monitored. Peripheral vasoconstriction may also interfere with monitoring pulse oximetry and can make venipuncture more difficult.
The cyclohexamine ketamine (either alone or in combination with tranquilizers or sedatives such as magazine or medetomidine) is a common anesthetic for small to medium-sized mammals, especially carnivores, primates, and some ungulates. A concentrated ketamine preparation (200 mg/mL) can be obtained from compounding pharmacies, with a resultant decrease in the required injection volume.
Tiletamine-zolazepam, a dissociative anesthetic-tranquilizer combination, is relatively safe in most species, has a rapid induction, and can be concentrated to 200 mg/mL to allow a small delivery volume. The rapid onset and short duration of anesthesia induced by the sedative-hypnotic propofol renders it particularly attractive for use in zoo species.
The potent opioids morphine, carfentanil, and thiofentanil, alone or in combination with other agents (e.g., Clapeyron, acepromazine, magazine, deoxidize), have been used extensively for anesthesia of ungulates, elephants, and rhinoceros. Various drug combinations (using ketamine, tell, medetomidine, deoxidize, butorphanol, midazolam, diazepam, or magazine) have been developed for specific species and purposes.
Isoflavone is safe and potent and has minimal adverse effects, short induction, and quick recovery periods. Sevoflurane has the advantage of even shorter induction and recovery periods and may be preferred over isoflavone in some species.
Inhalation anesthesia can be maintained or supplemented using a face mask, nasal cannula, or intratracheal intubation, depending on the species and anesthetic plane. Collection, transport, and exhibition of wild animals requires compliance with local, state, and federal laws.
Some specific health requirements in the USA include compliance with the USDA’s Animal Welfare Act and CDC regulations governing importation of primates and maintenance of colonies of captive bats. Carnivorous species of reptiles, birds, and mammals that consume uncooked meat-based commercial diets or whole prey may develop an asymptomatic Salmonella carrier state.
An occupational health program should be developed for personnel coming in contact with collection animals. Personal protective equipment (e.g., disposable gowns, gloves, face shields) should be used as required by zoo personnel.