Wounds in Antelope During Chemical Immobilization
Capture and/or chemical immobilization events carry inherent risks to wildlife regardless of size or species, but these risks are often more pronounced when dealing with larger species such as antelope and other hoofstock in the field. During capture/chemical immobilization, these risks include such complications as capture myopathy, aspiration, dehydration, hypothermia, hyperthermia, respiratory depression and/or arrest and cardiac arrest. Many of these complications can come about as the direct result of chemical immobilization, either due to inadvertent overdose, comorbidities or latent sensitivities in individual animals.
One complication that may be considered less critical or tangential in this context, but which must be seriously considered, is that of wounds incurred during capture events. These can occur as a result of an animal attempting to flee prior to immobilization, as it loses physical coordination during take-down after darting or, rarely, from the darts themselves.1
Physical injuries are certainly one of the most common threats to wild animals. In some cases, animals can incur severe injuries that kill them directly. In other cases, their injuries can affect them in ways that are indirectly fatal (e.g., reducing their ability to find food or to evade predators). Discounting human-related causes, these can come about as a result of myriad events, such as evading predators, fighting for mates or territory and accidents. Even when an animal doesn’t die as a direct or indirect result of an injury, it can be left in a permanently compromised state or with chronic pain.2
When an animal suffers a wound during capture/chemical immobilization, ethical imperatives obviously come into play. These dictate that those undertaking the required research or wildlife management protocols make every effort to ensure that the animal is promptly treated so that it can make as complete a recovery as is possible.
Antelope, Behavior and Wounds
Antelope comprise approximately 91 of the 140 or so known species of the Bovidae and Antilocapridae families; the former also includes sheep, goats, and domesticated cattle. The pronghorn antelope (Antilocapra Americana) is the only member of the Antilocapridae family.
Antelope vary widely in size; for example, the small royal antelope weighs an average of about four pounds, whereas the eland weighs up to 1,800 pounds.3 Despite being extremely widespread in geography and diverse in size, behavior and habitats, nearly all antelope are large hoofstock, and comparatively large as regards species typically encountered by researchers and wildlife managers in the field. Additionally, all antelope are prey animals, and have evolved with instincts and behaviors gauged to help them survive.
Consequently, all antelope will attempt to flee when approached in the field. Occasionally, this can result in injuries either before or after an animal is darted. If the approach by humans is protracted (e.g., a long vehicle or helicopter chase), the risk of complications and injury can be increased manifold. While a wide variety of injuries is possible in such circumstances, more often than not, when these occur, they are usually soft tissue injuries of varying severity.
Antelope have developed a number of methods to deal with predators, the most noteworthy of which is their speed and agility. If an antelope cannot evade its pursuer outright, it may try to hide in areas that are difficult to access. Some species will freeze in place to avoid being noticed, while others may stand their ground and defend themselves with their horns.2
Treatment of Wounds in Antelope
Most antelope injuries connected with capture events are experienced when attempting to flee human pursuers,1 and the most common injuries suffered are lacerations. While remote drug delivery via the dart itself is unlikely to result in a serious injury, darting can on occasion result in minor lacerations. Finally, in some cases an animal may need to be immobilized specifically for the treatment of a serious wound it has suffered due to other causes.
The first step will be to clean the wound. In the case of small, shallow lacerations, this can be done by flushing with a commercial povidone-iodine or other scrub solution. Deeper wounds can be flushed with povidone-iodine diluted with saline, and should generally not be sutured to allow for drainage.1 The current literature recommends high volume and, ideally, high-pressure irrigation unless the tissue is very delicate. The suggested lavage volume is 50 to 100 mL of fluid per centimeter of wound. Low-pressure irrigation is gentle to tissues and does not force bacteria deeper into the wound, but it does not debride as well as high-pressure irrigation, which can be performed with a pressurized fluid bag or a large syringe with an 18-gauge catheter.2
For suturing more superficial wounds that have been cleaned, a veterinarian should perform the procedure. If a veterinarian is not immediately available, non-absorbable sutures should be used.
Any animal receiving a laceration prior to or during an anesthetic event should receive systemic antibiotics to reduce the likelihood of infection. Procaine penicillin G combined with benzathine penicillin G is a common formulation is these instances. Long-acting oxytetracycine is also frequently used to treat hoofstock that have suffered lacerations.2
Given the inherent risks associated with chemical immobilization, there is no way to guarantee that injuries will not occur, particularly under field conditions. That said, the drug formulations currently available for immobilizing antelope and other wildlife have been refined to a degree that eliminates much of the risk that existed years ago. With the right drug formulations, proper planning and safety precautions in place, experienced personnel can have the expectation of effective and incident-free chemical immobilization of antelope in most cases.
1Kreeger T., Arnemo, J., Raath, J. Handbook of Wildlife Chemical Immobilization, International Edition, Wildlife Pharmaceuticals, Inc., Fort Collins, CO. (2002).
2vetfolio.com: Remote Injection Systems. https://www.vetfolio.com/learn/article/remote-inj...
3Friend, M., Thomas, N. J. Field Manual of Wildlife Diseases. In: Field Manual of Wildlife Diseases, United States Geological Survey, 361-368.
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.
NexGen 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. NEXGEN PHARMACEUTICALS, LLC IS NOT RESPONSIBLE NOR LIABLE FOR ANY ADVICE, COURSE OF TREATMENT, DIAGNOSIS OR ANY OTHER INFORMATION, SERVICES OR PRODUCTS THAT YOU OBTAIN THROUGH THIS BLOG POST.