Heat Stress In Llamas And Alpacas

4-12-04  REMINDER


Are You Ready for Summer ?
(a.k.a. Have You Sheared Your Llama / Alpaca Yet ?)

David E Anderson, DVM, MS, DACVS
Head and Associate Professor of Farm Animal Surgery
Director, International Camelid Initiative
Ohio State University
College of Veterinary Medicine
E-mail: Anderson.670@osu.edu

Spring is rapidly passing and the warmth of the sun melting away any trace
of winter. We are beginnings the throws of another spring parasite research
project. This time we are looking at some herbal interventions (who says I
am not open minded!). This reminds me of the individual variation of these
creatures. Every animal responds to stress - heat stress or any other -
differently. Today, with the temperature at 72 F, the humidity at 65 % (HSI
= 137 for those of you who remember the heat stress index calculation; HSI =
Temp + humidity), and direct sun exposure, some animals show low-grade heat
stress when handled. The llamas and alpacas are not yet sheared - that is
another lab for another day. Now, my mind drifts back to last year. 2003 was
a decent year for us, but several llamas and alpacas died of severe,
unrelenting heat stress in Ohio. 2002 was not much better but I was proud of
our clients' whose preparation for summer resulted in extremely few problem.
We saved most, but some get treatment too late. A friend sent me a reminder
about an upcoming newsletter and I starting to think of all the things I
wished all our clients knew to prepare for heat stress season. So - here are
my TOP TEN list of things to do. The list is not all inclusive, but these
are some of the most important things we need to do to protect the llamas
and alpacas from heat stress before it happens to you !
1. SHEAR - I recommend that all llamas and alpacas be sheared before June 1
every year. Barrel cuts seem to work OK, but not shearing is not an option.

2. SHADE - Lots of shade should be available. Most critical is that there is
enough shade for ALL of the animals to be shaded at the same time whenever
they want.

3. VENTILATION - A good breeze is worth a thousand words. The most important
thing is that the wind can get underneath the animals where the "thermal
window" is located. Fans should blow across the barn at floor level (not
down from a height). Barns should have cross-ventilation so that stagnation
does not occur in any area.

4. WATER - Clean, plain, fresh water should be available at all times. Water
should be replaced at least twice a day to keep it cool (not cold). Water
should be in the shade and animals should not have to compete for access.

5. BEDDING - Straw is bad in summer. This thick bedding closes off  the
thermal window and decreases access to ventilation. Sand bedding, especially
slightly moist, is very good at absorbing heat from the animals. Concrete is
hard, but cool and easy to clean and wet down.

6. WADING - I like pools. Llamas and alpacas will seek out puddles, ponds,
etc to get cool. This tends to make hair fall out if they lay around in
water too much of the time, but pools are very effective at allowing the
animals to self-regulate temperature. Bad for show season, but good for
non-showers. The pool should be in the shade and freshened daily.

7. MONITORING - Observation is the key to life. Watch your animals. If they
spend a lot of time eating, standing, walking around and being active then
they are probably happy and healthy. If they lay around most of the day and
are not active, then they may have sub clinical heat stress (early stage) and
intervention may be warranted. Watch your breeding males very closely. If
you see the scrotum getting pendulous, "baggy", or increasing in size, do
something immediately or you may loose fertility!

8. FEEDING - Eating and digesting hay takes a lot of work and generates a
lot of heat. Some have suggested that less hay, more grass and grains cause
less heat stress risk because heat production from digestion is minimized. I
question the application of this concept, but certainly pasture grazing is
the best management style.

9. ELECTROLYTES - I am a big believer in the protective effect of
electrolytes. I make water available that has salt, potassium, glucose, and
bicarbonate in it to help replace losses that occur in sweat and breathing.
I am a big believer in the protective effects of a balanced diet. Of
particular interest for heat stress is that adequate Vitamin E, Selenium,
Zinc, and Copper are available.

10. PREGNANCY - I prefer to see females in this area of the country having
crias in the spring. This optimizes easy re-breeding of females; allows
optimal lactation because of the nutrition of fresh grass; optimizes cria
health because of sunlight, clean pastures, and good nutrition; and prevents
females from having to suffer late gestation in the hot summer months.
Successful treatment of heat stress depends upon early recognition
(increased respiration, lethargy, increased recumbency, decreased appetite,
decreased cooperation with or participation in activity, flared nostrils).
Most of the above mentioned prevention strategies can be applied as
treatment. Consult a veterinarian at the earliest time for animals showing
abnormalities of behavior during summer months.



Heat Stress In Llamas And Alpacas

Ross Free, Veterinary Student
David E Anderson, DVM, MS, DACVS
College of Veterinary Medicine

Heat stress is a common occurrence for llamas and alpacas during the summer season. These animals originate from the Andes Mountains of South America, where high heat and humidity are not as common as in many areas of the United States. Llamas and alpacas are not adapted to handle these conditions, so it is critical to manage them in a way to protect
them from heat stress. Heat stress can lead to poor growth, illness, and even death of the animal.

The key to combating heat stress is prevention. There are many practices to prevent llamas and alpacas from suffering the effects of heat stress. It is important to know when llamas and alpacas are most in danger for heat stress. Commonly used is the heat index, which is simply a formula to estimate the risk of heat stress. The Heat Index can be estimated by adding the temperature (F) and percent humidity (%).  Typically, a heat index of less than 120 is safe, 120 to one 180 creates possible problems, and greater than 180 is the range where animals are in the most danger.

During the warmer months of the year there are many ways to keep your animals cool. Shade is an easy way to keep them from getting too hot. Under trees is a great place for them to relax and stay cool during the heat of the day. If there are no trees available, artificial shade can be provided by putting up temporary devices such as shade cloth.
When using artificial shade such as tents, barns, shelters, etc you should try to recreate the "tree" effect. Trees are tall, allow nearly unlimited movement of air, and are broad. A tall roofed broad barn with excellent air flow through creates a cool, comfortable environment.
Animals that are kept indoors are out of the sun, but it is important to keep good ventilation and air movement in the barn. Fans are a great way to keep the air moving and keep the animals cool. Two issues should be considered when using fans: 1) barn ventilation, 2) animal ventilation.

Tunnel ventilation barns are the most desirable because the "tunnel effect" maximizes cooling of the air. Fans placed in series (e.g. all facing the same direction) can create this effect and cool the barn.  Keeping several doors or windows open in the barn can also help create natural air movement and cooling throughout the barn. If available, having an air-conditioned room or area of the barn can help keep animals cool, or be used as a place to move animals that begin to show signs of heat stress.

Giving llamas and alpacas plenty of fresh water also helps prevent heat stress. There should be multiple sources of cool, clean water so all the animals have a place to drink. If possible, water should be kept in the shade. Electrolytes can also be placed in the
water to replace those lost during sweating. Electrolytes should not be placed in all the water sources, as some animals may not like the taste and prefer to drink unflavored water.

Shearing is one of the most important ways to help llamas and alpacas keep themselves cool. The fibers work to trap the heat close to the animal's body, shearing helps the animal to lose heat through evaporation more effectively. If possible, shearing from head to toe
(leaving about 1-3 inches of fiber on the body) is most effective, but barrel cuts (e.g. abdomen and thorax only) will help as well.

Differences are observed amongst the various camelids (e.g. llama, suri alpaca, huacaya alpaca, guanaco, vicuna) with respect to tolerance of hot and cold.

Proper management and husbandry can help prevent heat stress as well. If the animals need to be worked or handled for any reason, it should be done early in the morning in the coolest part of the day.  Also, breeding to have crias born in the spring is important. Gestation and giving birth cause stress for the female, and during the warmer months can cause considerable heat stress. Crias born in the warmer months are often born weak and can become dehydrated soon after birth.

Weaning should also take place during the cooler months, as it is a stressful time for both the cria and its mother. The body condition of the animal also plays an important role in heat stress. Obese animals are more prone to the effects of the heat, so proper management of weight is a good way to help these animals cool themselves. Emaciated animals also have increased susceptibility to extremes of environment.

Proper nutrition of the animals is also important. In particular, providing adequate selenium, vitamin E, copper, zinc, and B vitamins such as thiamine can increase tolerance of environmental extremes.  

Having water available for llamas and alpacas to wade or lay in can also help keep them cool. Streams and ponds in the pasture are a natural place for them to wade or even swim in. If these are not available, setting up baby pools can also provide an area for wading.
Llamas and alpacas that lay in the water can have their fiber damaged in the areas that are under water so this alternative may not be useful when animals are to be shown or exhibited in other ways. Sand pits or concrete floors can also provide a place for the animals to lay and cool themselves. Wetting down sand pits or concrete floors throughout the day will provide a cool place for them to lie. Sand can also be better bedding than straw, as straw can trap heat under the animal and prevent ventilation.

Monitoring the animals is important during the summer months, and signs of heat stress can be observed early. Signs to watch for are nasal flaring, open-mouthed breathing, increased breathing rate and effort, drooling, depression or dullness, not eating feed, scrotal
swelling in intact males, weakness, trembling, a rectal temperature greater than 104 degrees F, a heart rate over 90 beats per minute, or a respiratory rate over 40 breaths per minute. Taking temperatures often is a good way to learn what the normal temperatures of the animals are in the morning and afternoon, and helps the abnormal to be more easily
recognized. It is important to monitor the animals and recognize the signs early, so that the problems can be dealt with before they progress to more serious signs.

Treatment of llamas and alpacas with heat stress should first be to cool the animal down. Calling a Veterinarian should be the first action at the onset of signs, but steps can be taken to help the animal while waiting for the Veterinarian to arrive.  Hosing down the animal is
one way to do this, but it must be hosed down all the way to the skin because moisture in the fiber and not on the skin will only act to trap more heat and make the condition worse. If possible, moving the animal to an air-conditioned room will help cool it down as well. Placing the animal in the shade or in water such as a stream, pond, or wading pool will also help cool the animal down. Dehydrated animals should drink plenty of water, but if their condition does not allow them to do so, they can be re-hydrated by IV fluids. 

Shearing of animals suffering heat stress can also be helpful if it can be done in a way which does not further stress the animal and further complicate the problems.

During the warmest months of the year, heat stress becomes common in llamas and alpacas throughout the country. However, with proper management and care, the effects and losses due to heat stress can be greatly reduced. Taking preventative measures toward keeping
animals safe from the heat is the best way to deal with the heat during the summer.

David E Anderson, DVM, MS, DACVS
Ohio State University
E-mail: Anderson.670@osu.edu



P.Ramsey, D. Linden, and D. E. Anderson.  Dept. of Veterinary Clinical Sciences

      Alpacas and llamas are native to the Andes Mountains residing at an
altitude of 4,000-14,000 feet and their thermoregulation mechanisms have
become adapted to this mild environment. These animals often suffer heat
stress during the months of summer in North America.  Effective shade and
ventilation are critical to the prevention of heat stress.  However, many
owners use intermittent hydrotherapy as a preventative tool during
excessively hot days.  We hypothesized that a single administration of
water would have little effect on body temperature and that there would be
no difference between application to the whole body and the thermal window
(ventral abdomen, inner thighs, and perineum). This study was designed to
determine the interaction of shade and hydrotherapy on body temperature
regulation and thermal distribution.  18 llamas and alpacas were divided
into 3 treatment groups and 2 replicates (shade, sun): Group 1- no
hydrotherapy, Group 2- hydrotherapy on thermal window only, and Group 3-
whole body hydrotherapy.  First replicate: all 3 groups were placed in the
sun without any shade for 2 hours. Temperatures were recorded at 0, 15, 30,
45, 60, 90, 120 minutes rectally and at three different surface sites
(neck, back, and tail base).  Skin surface temperatures were determined
using laser surface thermometer.  Replicate 2 (24 hours after replicate 1)-
fully shaded barn and no box fan ventilation, (all assignments-same). With
the exception of the rectal temperatures, there was a slight decrease in
temperature at 30 minutes after hydrotherapy.  Unfortunately, this was
short-lived and the temperature of all the treatment groups rose as the
study went on.  Ultimately, there was no difference between the whole body
versus thermal window hydrotherapy treatment groups or the no hydrotherapy
group.  However, llamas and alpacas in shade had lower rectal and surface
temperatures compared with those in full sunlight.

David E Anderson, DVM, MS
College of Veterinary Medicine
The Ohio State University


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