Heat stress is a serious risk to animals during hot Australian summers. Groups at particular risk include young crias, full fleeced animals and late term pregnant females. However, as alpacas & llamas vary in their individual tolerance to heat and humidity, it is wise to monitor all animals carefully on hot and humid days.

Cause

Heat stress occurs when an animal’s thermoregulation mechanisms fail to keep the bodies temperature within acceptable levels. Average body temperature is around 37-39°C, and while an alpaca may cope with a short term rise, a prolonged temperature higher than 40°C can have serious consequences, including organ and central nervous system damage.

Alpacas & llamas seem to cope with short term heat (a hot afternoon for example) reasonably well but prolonged hot and/or humid days and warm nights can cause serious problems. We are fortunate as our summer days are often hot but the nights are cool, which gives the animals a chance to dissipate the heat built up during the day.

Environmental conditions creating a heat stress risk

Heat stress is caused by high ambient temperatures and/or high humidity. Dr Norm Evans recommends breeders in areas with high humidity implement heat stress prevention methods if the combination of temperature (in °F not °C) and % humidity is over 150 and to exercise extreme caution if it is over 180.  According to Eric Hoffman in the Complete Alpaca book this calculation doesn’t apply in areas of lower humidity. In these situations he recommends monitoring animals when the outside temperature exceeds 32°C. (I use this link to convert °F to °C http://www.onlineconversion.com/temperature.htm )

Prevention

Shearing

One of the best preventions of heat stress is to make sure your alpacas & fleecy llamas are shorn; a long mated fleece does not provide insulation but can trap heat, making life very unpleasant and even deadly for the unfortunate alpaca.

Shade & Shelter

Other preventative measures include providing shelter from direct sun. Shady trees are great, as is a shelter with plenty of air movement.

Water

Efficient thermoregulation depends on adequate water intake, as liquids are lost through evaporation (one of the body’s thermo-regulating mechanisms) must be replaced. It is essential to provide plenty of fresh clean water, and ideally there should be more than one watering point so subordinate animals are not prevented from drinking whenever they need to.  Also ensure there is a water source low enough for crias to get a drink.

I have noticed my alpacas & llamas are reluctant to drink warm water, so on days over 35°C I keep their water cool by adding large ice blocks. At least one bucket in every paddock has a bucket of cool water with electrolytes, this helps replenish minerals and salts lost in sweat. Most animals seem to drink from both buckets but some much prefer the electrolyte water.

On hot days make sure animals don’t have to walk too far to get water. I restrict my herd to a smaller paddock with plenty of trees, a shelter and several watering points. I provide access to the bigger paddock in the late afternoon when it starts to cool down.

Feeding

My herd change their grazing habits during summer. They rest during the heat of the day and graze at dusk, dawn and I expect throughout the night. To fit in with this pattern I hand feed before 6:30AM and after 7PM when it is cool.

Cooling

My alpacas & llamas love having their bellies, legs, armpits & under their tail hosed when it is hot. This area is most effective for cooling as it is free from fleece, the skin is thin & sweat glands are most accessible. 

Providing a way for your alpacas & llamas to cool off on demand is very useful. If using a dam be mindful of the extra risk from liver fluke and fleece rot from too much standing or sitting in water. Other cooling options include a kiddie wadding pool and sprinklers. Make sure water is changed fairly regularly in wading pools as it gets dirty when the animals walk through it and you don’t want them drinking contaminated water. I have been told that soaker hoses are the most suitable and effective sprinklers. Even simply wetting the ground can give the animals a chance to wet their bellies and cool down.

Minimizing Stress

I never attempt to wean crias during late summer as constant fence pacing can increase the risk for both the dam and cria. Try to avoid any stressful event that is likely to cause the alpaca or llama  to pace, stress or reduce their water intake.

Heat Stress & Pregnant Females

Pregnant females affected by high body temperatures can abort or delivery prematurely. In addition Dr Fowler notes that congenital defects are more prevalent in crias whose dams were exposed to 4-5 days of elevated heat in their first 50 days of gestation.

Heat Stress & Crias

Young cria are at particular risk of heat stress as they are not able to thermo-regulate as well as their dams.  Occasionally a dam happily sun-bakes while her cria sitting in full sun is over heating. You can cool a cria down by immersing them in cool (not icy cold) water.  Confining mum, cria and a friend into a shady area will keep the cria out of full sun.

Another risk for crias is dehydration. Many dams don’t want to get up on hot a day, which denies access to their udder. If necessary, make the mums get up so their crias can have a drink. If you are bottle feeding try offering water in between milk feeds to keep the cria hydrated. On days over 30°C I offer my bottle feed lambs water mixed with Vytrate every two hours.

Heat Stress & Stud Males

A couple of really hot days can kill sperm and cause a male to be infertile for 30-60 days. We avoid summer breeding for this reason and because the act of mating can increase the risk of heat stress for the male. Signs a male’s fertility has been compromised include loose and extended skin in the testicular region or swelling and fluid build up in the scrotum.

Symptoms & Treatment

Every animal responds differently when they are suffering from heat stress. The earlier the condition is detected the easier it is to treat. If you observe an animal acting differently to normal it is worth checking out. The most common clinical signs include lying in the paddock, reluctance to move, and a rim of froth, drool or saliva around the lips. More serious signs include breathing with an open mouth, stiffness due to muscle soreness and uncoordination. Heartbeat and body temperature may be elevated

If caught early treat the alpaca with cold water baths, alcohol baths, ice bags in the armpits or in extreme case cold water enemas. If giving cool water enemas make sure a very low water pressure is used and the water exits at the same rate it enters. Also be aware that this treatment will give a false rectal temperature reading for a period of time. Dr Fowler recommends only using a cold water enema if the animal’s temperature is above 42°C. Always contact your vet if you think your animal is suffering from heat stress. They can advise on a course of action and treat the effected animal(s) both short term and for any of the long term complications caused by prolonged heat stress.

References:

Alpaca Field Manual, Dr C. Evans

The Complete Alpaca Book, Eric Hoffman

Antenatal, Birthing & Cria Care, Dr Ewen Mc Millan & Carolyn Jinks