Hypothermia and Hyperthermia in Llamas During Capture and Chemical Immobilization

Llamas (Lama glama) are domesticated camelids that are believed to be descended from the wild guanaco (Lama guanicoe). These New World camelids come from a group known as lamoids, which includes llamas, alpacas, vicuñas, and guanacos. Fossil evidence indicates that all camelids originated in North America, and it is believed that one group moved north, crossing the Bering land bridge and evolving into camels, while others migrated south and became New World camelids.¹Most lamoids have been domesticated for thousands of years. In fact, many lamoid species have ceased to exist in the wild, while their domesticated descendants are flourishing. Some have been interbred and developed for various uses, such as pack animals, food or fleece.

The range of the llama encompasses the high Andes mountains of South America. They are slender-bodied, with long legs, long necks, short tails and large ears. Llamas average 45 inches in height at the shoulder, with adult males weighing between 300 and 400 pounds, and adult females weighing between 230 and 350 pounds.^2,3

Llamas are known to be gentle, intelligent animals that are easy to train. In a very short amount of time, a llama can be trained to accept a halter, follow on a lead or get in and out of a vehicle. They can also be trained to pull a cart or carry a pack. With humans, they are very sociable, but require the companionship of other llamas.²

The largest of the lamoids, llamas are used in the Andean highlands chiefly as pack animals. An adult llama can carry loads of 50 to 75 pounds for up to 20 miles in a day. Pack trains of llamas can include several hundred animals, and regularly move large amounts of goods over the rough Andean terrain.² Sometimes, a llama carrying too heavy a load will refuse to move, lie on the ground and spit, hiss, or kick until the load is lessened.

Like the smaller alpaca, llamas are also valued for their fleece. As a result, llama and alpaca farming has become a popular cottage industry worldwide. The llama’s natural environment in the South American Andes is at high altitude and is relatively cool. Thus, the llama’s health benefits from periodic shearing if they live where summers are hot. Llamas vary considerably in fleece length and thickness, so the importance and frequency of shearing depends on the individual animal and the climate. A llama needs about three inches of its fleece for winter warmth, so a llama sheared to one inch in the spring can grow an adequate coat by the time winter comes.³

In its natural environment, the llama is a grazer and browser, with a diet consisting of grasses and leaves. Llamas are adaptive feeders, however; on farms, they will eat grasses, shrubs, trees and hay. Three to five llamas can be grazed per acre, and a bale of hay will feed an adult llama for around a week.²

Like other camelids, llamas are not particularly loud animals, but they do use vocalizations. Llamas occasionally emit a humming noise. Females will hum to their offspring, and males emit a type of gurgling sound, often during breeding. Breeding males will “yell” at each other, and if a llama perceives danger, it will put out alarm call to warn the rest of the herd.^1,2 In the wild, the dominant male typically scouts from a high vantage point to watch over his herd of females, vocalizing at any sign of danger.

Hypothermia and Hyperthermia in Llamas

The capture of llamas can be a stressful event which has the potential to cause capture-induced hypothermia or hyperthermia even despite their high level of domestication and their pleasant nature. Either of these complications can result in morbidity or mortality. The severity of the capture-induced hyperthermia has been associated with the likelihood of organ damage, alterations in electrolyte balance (possibly leading to dehydration), increased oxidative stress and death.⁴ It has also been called one of the primary indications for the development of capture myopathy, another potentially fatal complication of capture.

The mechanisms underlying the increase in body temperature during capture-induced hypothermia and hyperthermia are not fully understood, but the sympathetic stress response appears to be a factor. Even animals engaging in low levels of activity during capture with mild ambient temperatures can develop severe hyperthermia.⁵

Avoiding Hypothermia and Hyperthermia in the Llama

The normal body temperature for adult llamas and crias (offspring) is from 96 to 102 degrees Fahrenheit, although the temperature of newborn crias can run slightly higher. Measuring body temperature should always be standard procedure during all anesthetic events involving llamas. Hypothermia is more common in smaller animals because of the large surface area-to-volume ratio, but instances of both hypothermia and hyperthermia have been reported during the capture of llamas.

Some of the drugs used in the chemical immobilization of llamas are known to suppress normal thermoregulatory mechanisms, potentially causing hypothermia or hyperthermia. Hyperthermia however, is also common immediately after the immobilization of both captive and free-ranging hoofstock due to excitement and struggling after being darted with immobilizing drugs.^4-6

Intubation has been recommended for immobilized llamas that need to be transported or anesthetized for greater than twenty minutes,and monitoring core body temperature is essential in llama anesthesia.⁴ 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 primary component of llama anesthesia.⁶

Treating Hyperthermia in Llamas

Physically cooling the captured llama is the method most widely recommended for improving their chances for survival during chemical immobilization. Physical cooling has been known to be highly effective even when capture-induced hyperthermia in a llama is severe. Those attending or on the capture team should be prepared for this possibility and have the proper equipment on hand.

Other recommendations for cooling captured llamas include placing the animals in the shade and dousing them with water using portable mist sprayers, followed by rapid intravenous (IV) fluid therapy.⁵ In animals with body temperatures greater than 41°C, the use of cold water enemas and intravenous infusion of cold Ringer’s lactate are also recommended.⁶

Ice packs have been reported to restore the body temperature of hyperthermic llama to pre-capture levels.⁵ Since carrying water is far less cumbersome and difficult than transporting and maintaining ice-packs in the field, water-dousing is the more practical and effective first intervention for cooling a llama with capture-induced hyperthermia.

Treating Hypothermia in Llamas

Hypothermia during chemical immobilization events (sedation or anesthesia) is a common adverse effect of anesthesia in many species. Smaller animals are generally more susceptible to hypothermia during anesthetic events, but large hoofstock and even carnivores can be affected.⁶ External heating devices or other thermal support during and after anesthesia can dramatically improve outcomes in the event of hypothermia during or after a procedure. Handlers should note that the time of recovery from anesthesia will be longer in case of injectable anesthesia rather than inhalant anesthesia.

In addition to abnormally low body temperature, signs of hypothermia in the llama may include:

• Shivering
• Stiff muscles
• Pale or gray gums
• Fixed and dilated pupils
• Low heart and breathing rates

In cases of mild hypothermia, shivering may be the only observable symptom. As the condition increases in severity, some of the other listed symptoms can become evident. The llama’s vital signs may become increasingly erratic as its body goes into heat conservation mode.⁶ At this juncture, the animal’s body is trying to keep its vital organs from shutting down by restricting the blood flow from other parts of the body.

To raise the llama’s body temperature, water bottles filled with warm water and placed around the animal’s body should be used. External heating devices (e.g., heating pads) may also be employed, although these should be used with care, as it is easy to burn an animal’s skin.⁷ Returning the animal to a warm environment and/or using heat lamps (if available) can also be helpful.