Capture Myopathy in Antelope
Capture myopathy (CM) is a serious condition that can occur in wild and domestic animals wherein muscle damage results from extreme exertion, struggle, or stress. It is also known as exertional myopathy, overstraining disease and exertional rhabdomyolysis.1 Capture myopathy most often occurs as a result of capture, transport or chemical immobilization, but it can also be the result of other natural causes of stress, such as in prey animals attempting to avoid or struggling with predator animals.2 It is of particular concern in cases when it is a cause of death in wild animals that are handled by humans.
Capture myopathy can occur in any animal under extreme stress, although it is thought that some species may be more predisposed to it than others due to their natural temperament and physiological characteristics.3 Capture myopathy has been most widely studied in ungulates and birds, although it is believed to potentially affect any captured wildlife species. It has also been observed in coyotes, badgers, primates, and many other species.2 Ungulates in North America that have been reported with this condition have included white-tailed deer, mountain goats, bighorn sheep, pronghorn antelope, bison, moose, and elk.2,3 It is believed that capture myopathy can even occur in fish and amphibians.1
Causes and Clinical Signs of Capture Myopathy
Capture myopathy can occur naturally when antelope are attempting to avoid predation, but for the purposes of this discussion, capture myopathy will be the result of these animals being captured and/or immobilized with or without chemical means being involved. Antelope, like other animals, are adapted to escape from predators, but they are not adapted to struggle for long periods of time in human-constructed restraints.3 When animals overexert themselves (e.g., struggling in a trap) to the extent that physiological imbalances develop and result in severe muscle damage, capture myopathy results.2 Increased ambient temperatures and repeated chemical immobilization can increase the risk of animals suffering from capture myopathy.4
Source/Credit: Oxford University Press
Clinical signs of capture myopathy in the antelope can vary depending on the species and the cause of exertion.2 The method of capture and restraint is also a determinant in occurrences of CM. The available literature states that capture myopathy may result in sudden death, or that clinical signs may develop hours, days, or up to two months following capture.4 The clinical signs during early onset include elevated respiratory rate, heart rate, and body temperature.1,3 Body temperature increases during exertion, with higher temperatures being associated with death due to CM. The increase in body temperature can be above 42°C.4 Muscle spasms, stiffness and lameness are also clear signs of CM. Animals often become recumbent and may stumble. If dark red-colored urine is noted, this is an indication that the animal's muscles are breaking down and that its kidneys have been severely affected.2-4 Death of the animal usually follows. If the animal survives the acute stage of the condition, scarring of heart and skeletal muscle tissue may permanently debilitate the animal.4 Upon necropsy, light-colored skeletal and cardiac muscle is indicative of capture myopathy being the cause of death.
Preventing Capture Myopathy in Antelope
There is no treatment for capture myopathy, prevention being the best method of avoiding this condition. Care should be taken in case of handling of animals that tend to be more susceptible to capture myopathy. An anesthetic protocol consisting of good anesthetic agents can aid significantly in preventing capture myopathy in antelope. In such cases, the remote delivery of anesthetic agents would be a superior methodology to trapping the antelope prior to the anesthetic event.
The team in the field should be thoroughly aware of the risks of capture myopathy and make every effort to prevent its occurrence. Antelope (and indeed, any wild species) should only be captured when necessary, and the negative effects that capture may have on an animal's health should always be considered before beginning a capture or initiating an anesthetic event.5 Capture methods that minimize animal stress, struggling and handling time should be utilized. Appropriate methods may vary depending on the subspecies, so research can be helpful in identifying the ideal capture method. It has been reported that using a combination of Xylazine HCL and Ketamine HCL can decrease the chance of capture myopathy, but this is by no means a guarantee of avoiding capture myopathy in any antelope.3
1Friend, M., Thomas, N. J. Field Manual of Wildlife Diseases. In: Field Manual of Wildlife Diseases, United States Geological Survey, 361-368.
2Williams, E. S., Thorne, E. T. 1996. Exertional Myopathy (Capture Myopathy). Noninfectious Diseases of Wildlife, Second Edition, 181-193 Iowa State University Press, Ames, Iowa, USA.
3Blumstein, D., et. al. The evolution of capture myopathy in hooved mammals: a model for human stress cardiomyopathy?Evolution, medicine, and public health vol. 2015,1 195-203. 21 Jul. 2015,
4Kohn, Tertius. (2013). Capture myopathy mystery.
5Businga NK, Langenberg J, Carlson L. Successful treatment of capture myopathy in three wild greater sandhill cranes (Grus canadensis tabida). J Avian Med Surg. 2007 Dec;21(4):294-8. doi: 10.1647/2005-013R1.1. PMID: 18351009.
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.