There are few wild species that are as iconic as the camel. There are three recognized species of camel; these are the dromedary camel (Camelus dromedarius), the Bactrian camel (Camelus bactrianus) and the wild Bactrian camel (C. ferus). Approximately 90% of the world's camels are dromedary camels (also known as Arabian camels) and nearly all of these are domesticated.1 Wild Bactrian camels are leaner in build than their domesticated counterparts, with smaller humps and less hair.
Camels are found in northern Africa and southwestern Asia, and have been introduced into Australia. Bactrian camels are native to the Gobi Desert in China and the Bactrian steppes of Mongolia. The dromedary camel has one back hump, while the domesticated Bactrian and wild Bactrian camels have two humps. Arabian camels have been domesticated for approximately 3,500 years and have been long valued as pack animals that can carry large loads (over 100 lbs.) for up to 25 miles a day.2 Camels have long been used by humans for their wool, milk, meat, leather, and dung (which can be used for fuel).3
These ungulates have an unmistakable appearance, with their humped back, short tail, long legs, and a long neck. All three camel species are approximately 10 feet long and 6-1/2 feet high at the hump. Males typically weigh in at 900 to 1,400 pounds; females are about 10% smaller and lighter. Their color is light brown to medium gray. Bactrian camels are slightly darker and stockier, and have more hair than wild Bactrian camels.2 All camels have heavy eyelashes which protect their eyes from blowing sand, and their nostrils can be squeezed shut.
Like cows, camels are ruminants; they are diurnal and spend much of their days eating. Each half of their split upper lips move independently, so camels can forage short grass very near to the ground. Their lips can break off and eat tough vegetation such as thorns or salty plants, and it has been reported that they will even eat fish.3
Camels can go a week or more without water, and a camel can last for several months without food. Their humps store up to 80 pounds of fat, which camels break down into water and energy when food is not available.2,3 The humps give camels their noted ability to travel up to 100 miles in the desert without water. When camels do drink, they can drink 30 gallons of water in less than 15 minutes.
All species of camel are seasonal breeders with females coming into heat during the breeding season. This normally occurs during the winter months, from November to March.1
One of the more common post-sedation and post-anesthesia complications in both domestic and exotic animals is vomiting. It is not uncommon for both humans and animals to vomit once or twice after a surgical procedure. However, if the vomiting continues, it can be a sign of an emerging complication. A far more serious complication involves vomiting that occurs during a procedure, as this can pose grave risks due to anesthetic aspiration.
Anesthetic aspiration involves a camel vomiting food from its stomach during a surgical procedure, which subsequently infiltrates into the lungs. This can lead to aspiration pneumonia. While modern protocols for anesthesia and sedation in wildlife are generally safe, respiratory complications such as anesthesia-related aspiration and pneumonia can be fatal.4
Anesthesia-related aspiration is defined as the entry of liquid or solid material into the trachea and lungs. As indicated above, this occurs when patients without sufficient laryngeal protective reflexes (as a result of sedation or anesthetic agents) regurgitate gastric contents. “Pulmonary syndromes of differing severity can result, ranging from mild symptoms such as hypoxia to complete respiratory failure and acute respiratory distress syndrome (ARDS).”4 In extreme circumstances, cardiopulmonary collapse and death can occur. The related pulmonary syndromes can include acid-associated pneumonitis, particle-associated aspiration (airway obstruction) or bacterial infection. Which of these develops depends upon the composition and volume of the aspirate.
Acute intraoperative aspiration (aspiration during a surgical procedure) is a potentially fatal complication with significant associated morbidity. Animals undergoing thoracic surgery are at increased risk for anesthesia-related aspiration, largely due to the predisposing conditions associated with this complication. Awareness of the risk factors, predisposing conditions, precautions to decrease risk and immediate management options by the veterinarian is imperative to reducing risk and optimizing outcomes associated with this complication.4
The veterinary care of domestic and non-domestic hoofstock has become commonplace due to the integration of veterinary medicine in wildlife management programs, zoological collections, exotic animal ranching expansions and the private collection of wildlife species.5 As a result, research and wildlife veterinarians are required to amass the requisite knowledge associated with safely anesthetizing and handling these animals.
The sedation and anesthesia of camels requires the knowledge the pharmacology of the drugs being used, as well as the wide variation in dose response among sub-species of these animals. A major challenge—and one which impacts potential complications such as anesthetic aspiration—is correlating the available pharmaceutical tools with the environment and conditions, as well as the procedures and events preceding, during, and following the anesthetic event.6 For example, an anesthesia protocol that’s practical in a fenced captive environment may not be appropriate in a free-ranging environment or large enclosure.
Today, the quality of sedation, anesthesia and analgesia achievable in camels and other wildlife species has been made possible through the availability of new, receptor-specific and highly potent agonist-reversible pharmaceuticals and the improved knowledge of CNS receptors.
Despite their size, camelids (camels, llamas and alpacas) are often agreeable when it comes to handling, thus physical restraint and local anesthetic techniques are frequently used to provide immobility and analgesia. General anesthesia techniques are similar to those for ruminants and horses.7,8 Regurgitation of compartment one (C1) of the stomach contents, similar to ruminants, and postoperative nasal congestion and associated respiratory distress postextubation are potential hazards associated with anesthesia. In most cases, recovery from anesthesia is generally uneventful.8
Monitoring core body temperature is essential in camel anesthesia.6 Until the more recent use of formulated drugs (e.g., combinations of α2-agonists such as medetomidine, detomidine, xylazine and their reversal agents), opioids were the mainstay of camel anesthesia in wildlife and captive care.5
Guidelines for the preparation of camels for anesthesia and surgery include decreasing the size and pressure in C1 before anesthesia, withholding food for 12 to 18 hours in adults and withholding water for up to 12 hours. Withholding food or water in neonates is not recommended, as this increases the risk of dehydration and hypoglycemia. Camels younger than one month of age rarely regurgitate during anesthesia. It is also recommended that camels be orotracheally intubated for procedures lasting more than 20 minutes.8
For the prevention of anesthetic aspiration, histamine (H2) antagonists such as cimetidine, famotidine, nizatidine, and ranitidine and proton pump inhibitors (PPIs) such as dexlansoprazole, esomeprazole, lansoprazole, omeprazole, pantoprazole, and rabeprazole have been shown to be effective in increasing the pH and reduce the volume of gastric contents.4 Additionally, prokinetics (e.g., domperidone, metoclopramide, erythromycin and renzapride) promote gastric emptying and are believed to reduce the risk of aspiration.6
The first step in successful management of an intraoperative aspiration is the immediate recognition of gastric content in the oropharynx or the airways.4 The animal should be immediately positioned with the head down and rotated laterally if possible. Orotracheal and endotracheal suctioning is indicated, either before or after orotracheal intubation, depending on whether regurgitation continues and if the airway is visible. It is recommended that the airway be secured as rapidly as possible to prevent further contamination and to facilitate airway clearance.6 Flexible bronchoscopy is an important adjunct to orotracheal and endotracheal suctioning, and having a flexible bronchoscope at the ready if possible is a sound prophylactic measure. If particulate matter is present in the airway, rigid bronchoscopy may be required.4-7
1britannica.com.