MK Deer Tranquilizer
Nondomestic ruminants such as deer can be encountered in the wild, on exotic animal or cervid ranches on breeding farms, and in zoos or petting farms. In order to handle or treat species of deer, most require manual restraint using a hydraulic squeeze or drop floor chute or immobilization. The approach to restraint and anesthesia for these species is governed by the level of habituation to handling and human contact, the handling facilities (holding pens, raceways and squeeze chutes) available, and the animal handling expertise of the caretakers.1 Like all wild ruminants, deer are prey species, and flight is usually their first response to any threat. The more intensively reared or tame the animals, the easier they will be to work and decreasing the flight zone will make the capture or immobilization procedure less unpleasant and stressful for the animal, the handler, and the veterinarian.2
In the wild, or in circumstances wherein use of a squeeze chute or other manual restraint is impractical, sedation or immobilization are necessary. Extremely tame or hand raised animals may allow administration of anesthetic agents via syringe. Pole syringes can be used on animals that can be confined to small pens or stalls. Remote delivery systems involving darts delivered via blow pipe, dart pistol or rifle can also be used to deliver anesthetic and/or sedative agents to deer.
Reasons that a deer may need to be sedated/anesthetized include:
- Regulatory testing (e.g., TB and Brucellosis)
- Semen collection
- Artificial insemination
- Antler Removal
- Transport
- Illness or injury
Immobilization Agents for Deer
The possession and use of drugs used to capture wildlife is governed by federal and state regulations. All drugs currently used to sedate or immobilize wild animals are prescription drugs and must be used by or on the order of a licensed veterinarian. In order to comply with regulations, non-veterinarians and organizations must ensure that a valid veterinarian-client-patient relationship has been established. This requires that a veterinarian must be involved in the process, but it does not necessarily mean that a veterinarian be present during the immobilization process. Some drugs used on wildlife are also classified as controlled drugs. Possession of controlled drugs requires a Drug Enforcement Agency registration number, special record keeping, and special storage requirements.1
The ideal immobilization drug or formulation for deer has a wide safety margin, small volume for delivery, and is fully reversible. A small volume will facilitate rapid administration especially if remote delivery systems are used.1,2
Paralytic Drugs or neuromuscular blocking (NMB) drugs were some of the first drugs used for the chemical immobilization of wildlife. Despite their long history of use, NMB drugs are generally inferior to modern drugs and drug formulations. Two major deficiencies as regards NMB drugs exist: 1) NMB drugs have a very low safety margin; dosage errors of only 10% can result in either no effect (underdosing) or death by asphyxia (overdosing). 2) NMB drugs are virtually devoid of central nervous system effects because of their inability to cross the blood-brain barrier.2
Tranquilizers/Sedatives are primarily used in wildlife immobilization as adjuncts to primary anesthetics (e.g., ketamine) to hasten and smooth induction and recovery and to reduce the amount of the primary agent required to achieve immobilization. The α-adrenergic tranquilizers (e.g., xylazine, medetomidine) are potent sedatives and can be completely antagonized. These are often combined with ketamine, Telazol, or carfentanil. As single agents, they are capable of heavily sedating animals to the point of relatively safe handling. However, animals sedated with these tranquilizers generally can be aroused with stimulation and are capable of response or attack.2
Dissociative Anesthetics are characterized by producing a cataleptic state. Ketamine is probably one of the most widely used drugs of this type for wildlife immobilization because of its efficacy and safety. When used singly, ketamine can cause rough inductions and recoveries, and convulsions are not uncommon.2 Due to this aspect, they are usually administered concurrently with tranquilizers or sedatives.
Opioid Anesthetics have been used for animal immobilization since the middle of the last century and are among the most potent drugs available for this purpose. A major advantage of opioids is the availability of specific antagonists. The potency of opioids is both an advantage and disadvantage. An advantage is that the reduced volume of drug required for immobilization makes these the only class of drugs capable of remote immobilization of large animals. A disadvantage is that they are potentially toxic to humans. Death is almost always due to respiratory failure. Opioid immobilizing agents should never be used by clinicians working alone or without having an antagonist immediately on hand.2
In the Field
The Handbook of Wildlife Chemical Immobilization (Arnemo & Kreeger, 2018) stresses preparation quite strongly. Before immobilization procedures are executed, it is essential that the veterinarian and support personnel have all drugs and equipment that may be needed. “Fishing tackle boxes usually make good receptacles for all this and they come in a variety of sizes and shapes to suit almost all tastes. Vests with multiple pockets, such as a fly fishing or photographer’s vest, can be used to carry most items and they free the hands to carry such things as dart guns and pole syringes.”2 Darts should be prepared beforehand, with one or more darts loaded before the animal is approached. All loaded darts should be safely stored (especially in transit) to prevent accidental injection.
The target animal—in this case, a deer—should be approached quietly and calmly, even if the animal is captive and restrained in a chute, as rapid or exaggerated movements can panic the animal. “If captive animals are accustomed to a routine such as feeding or cleaning, try to mimic that activity (at the same time of day) to allow a closer approach.”2 Wild deer and other animals can sometimes be approached with a vehicle, but the shooter should always remain inside the vehicle. Distance and wind should be estimated, as many dart guns can be adjusted to deliver more or less propellant to the dart. This is critical, since overpowered darts can cause injury or death, and underpowered darts can miss entirely and spook the deer.2
The preferred route for the administration of an immobilizing drug by remote delivery is via intramuscular injection. The aim is to hit the animal in a specifically-selected site, causing injection into vascular tissue and facilitating rapid absorption of the drug. Not all areas of an animal's body are equally well-suited for injection by remote delivery; thus, the injection site should be carefully chosen.
MK Tranquilizer for Deer
The MK Kit from NexGen Pharmaceuticals is a premixed formulation developed to provide veterinarians and wildlife handlers with a field-tested immobilization anesthesia option that can be effectively used to immobilize a broad range of exotic animal species. Medetomidine (5mg/ml) provides superior pain relief and muscle relaxation to other compounds employing α-2 adrenergic agonists, with Ketamine HCl (150 mg/ml) supplying an effective paralytic.
The neck is generally a suitable site for large animals with muscular necks, such as deer. Care should be taken to avoid hitting the jugular vein, the upper neck and the head. The ideal injection site is the trapezius muscle mass at the upper base of the neck. The shoulder is a suitable injection site in many larger species. This region is well-muscled, presenting a flat, perpendicular target. It is surrounded by relatively resilient areas and presents a fair-sized target in animals that are robust enough to be darted with remote delivery equipment.
For those who may be new to utilizing premixed formulations, it is important to understand the level of anesthesia being administered with Medetomidine/Ketamine sedation. MK is a deep sedation, not to be confused with other sedations that are moderate. In combination, the two provide safe, smooth induction times and excellent recovery results.
1Wolff, P. Capture and Immobilization of Exotic Small Ruminants. In: NAVC Conference 2009, 366.
2Arnemo, Jon & Kreeger, Terry. (2018). Handbook of Wildlife Chemical Immobilization, 5th Ed.
About NexGen Pharmaceuticals
NexGen Pharmaceuticals is an industry-leading veterinary compounding pharmacy, offering sterile and non-sterile compounding services nationwide. Unlike other veterinary compounding pharmacies, NexGen 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. We also specialize in wildlife pharmaceuticals, including sedatives and their antagonists, offering many unique options to serve a wide array of zoo animal and wildlife immobilization and anesthesia requirements.
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.
Disclaimer
The information contained in this blog post is general in nature and is intended for use as an informational aid. It does not cover all possible uses, actions, precautions, side effects, or interactions of the medications shown, nor is the information intended as medical advice or diagnosis for individual health problems or for making an evaluation as to the risks and benefits of using a particular medication. You should consult your veterinarian about diagnosis and treatment of any health problems. Information and statements have not been evaluated by the Food and Drug Administration ("FDA"), nor has the FDA approved the medications to diagnose, cure or prevent disease. Medications compounded by NexGen Pharmaceuticals are prepared at the direction of a veterinarian. NexGen Pharmaceuticals compounded veterinary preparations are not intended for use in food and food-producing animals.
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