Capture Myopathy in Bactrian Camels During Capture and Chemical Immobilization
The two-humped or Bactrian camel (Camelus bactrianus) once served as a primary means of transport between East and West, especially during the time of the Silk Road. Named after an ancient region in Central Asia, “Bactrian” was first used to distinguish this camel from the dromedary (Arabian) camel, which has only one hump.1 According to fossil evidence, the ancestors of modern camels evolved in North America during the Palaeogene period and later spread to Asia, subsequently becoming extinct in North America.2
Bactrian camels are one of the few animals that are native to the Gobi desert in north central China, where fluctuating temperatures, scarce food and water and rugged terrain create a difficult environment. The rugged nature of the camel’s range makes it difficult for other animals to survive there. Consequently, Bactrian camels have few competitors or predators. This, and their adaptations to the harsh habitat allow them to obtain sustenance and protect themselves from wind, heat, and cold.
Bactrian camels forage throughout the day, eating a wide variety of plant. It has been reported that they will also eat meat and fish when plat foods are unavailable.1,2 Their two humps store between 30 to 50 pounds of fat, which allows them to survive with little food for extended periods of time. Like dromedary camels, Bactrian camels have evolved specialized blood cells which store fluids to help keep them in good health even when they are dehydrated.3 When they do find water, they can drink up to 30 gallons at a time.
Bactrian camels usually gather in small groups of up to six animals as they migrate through the desert in search of food and water. While most Bactrian camels are domesticated, wild Bactrian camels still exist. These live in herds of about 6-20, although they occasionally aggregate in groups of up to 30 individuals. Herds typically consist of one alpha male leading adult females and their calves.
Both camel species are polygynous, wherein the dominant male will mate with any of the females in the herd. The Bactrian camel's breeding season takes place in March and April. Calves are born weighing about 37 kg and are fully mobile within the first 24 hours. Calves in the wild are typically weaned within the first two years.1
Capture Myopathy Explained
Capture myopathy (CM) is a serious condition that can occur in both wild and domestic animals. The condition is described as muscle damage resulting from extreme exertion, struggle, or stress. It is also known as exertional myopathy, overstraining disease and exertional rhabdomyolysis.4 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 predators.5 Obviously, capture myopathy is of concern when it is a cause of death in animals that are handled by humans, such as capture teams.
Capture myopathy can occur in any animal under extreme stress, although some species may be more predisposed to it than others due to their temperament and physiology.6 Capture myopathy has been most widely studied in ungulates and birds, although it is believed that it can occur in any captured wildlife species.5
Clinical Signs of Capture Myopathy
Since modern camels have few predators and are largely domesticated, for the purposes of this discussion, capture myopathy will be the result of these animals being captured and/or chemically immobilized. When animals overexert themselves (e.g., attempting to flee a capture team) to the extent that physiological imbalances develop and result in severe muscle damage, capture myopathy results.5,6 Increased ambient temperatures and repeated chemical immobilization can increase the risk of a camel suffering from capture myopathy.7
Clinical signs of capture myopathy in Bactrian camels can vary depending on the cause of exertion.5 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.4,6 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
Lameness, muscle spasms and stiffness are also clear signs of CM. If dark red-colored urine is noted, this is an indication that the camel's muscles are breaking down and that its kidneys have been severely affected.5-7 Death of the animal usually follows. If it survives the acute stage of the condition, scarring of heart and skeletal muscle tissue may permanently debilitate the animal.7 Upon necropsy, light-colored skeletal and cardiac muscle is indicative of capture myopathy being the cause of death (see photo).
Preventing Capture Myopathy in Bactrian Camels
As there is no treatment for capture myopathy, prevention is the best method of avoiding it. Care should be taken in handling animals that tend to be more susceptible to capture myopathy, which includes large hoofstock. An anesthetic protocol consisting of good anesthetic agents can aid significantly in preventing capture myopathy in camels. The remote delivery of anesthetic agents is a superior methodology to trapping an animal prior to the anesthetic event.
The capture team or handlers should be thoroughly aware of the risks of capture myopathy and make every effort to prevent its occurrence. Bactrian camels 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.7,9Capture methods that minimize animal stress, struggling and handling time should always be utilized. It has been reported that using a combination of Xylazine HCL and Ketamine HCL can decrease the chance of capture myopathy, but this is not a guarantee of avoiding this condition in Bactrian camels.6
4Friend, M., Thomas, N. J. Field Manual of Wildlife Diseases. In: Field Manual of Wildlife Diseases, United States Geological Survey, 361-368.
5Williams, 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.
6Blumstein, 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,
7Kohn, Tertius. (2013). Capture myopathy mystery.
8Businga 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.