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Florida
Farm and Feed
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Heat
Stress and Heat Stroke
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Heat Index
When the surrounding temperature approaches the normal human body temperature
of about 99 F our bodies must regulate that internal temperature and get
rid of the excess heat our bodies generate. To do that, human beings sweat
and this sweat then evaporates causing a cooling effect. Other animals,
like dogs and cats do not sweat, but they pant expelling the excess heat
in their breath. Most animals with fur or feathers, pant. Most animals
with hair, sweat. Other animals like reptiles must go underground to cooler
surroundings, or die. See
chart of heat index temperatures (opens new window)
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Equine
Heat Stress and Heat Stroke
from Equines
of the world
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Summertime can be an extremely dangerous time for horses,
especially if their owners aren't aware of the dangers in overheating...or
"Heat Stress", when the condition progresses, it can lead to a life-threatening
condition called "Heat Stroke". The best prevention for equine owners, is
to know how to identify heat stress in a horse before it progresses to heat
stroke. If a horse is being exercised on hot days, extra care and attention
must be given because there is a significant increase in the amount of heat
produced by working muscles. Heat production can increase as much as 50%
during intense exercise as compared with heat production when the horse
is at rest. A horse increases its sweating rate to move more blood to the
capillaries under the skin and breaths much harder in an effort to release
this build-up of heat. The most commonly observed signs of "Heat Stress"
are profuse sweating, rapid breathing, and a rapid heart rate. Some horses
have a condition leaving them little or no ability to produce sweat, these
horses are called "Anhydrotic". Since heat loss is mainly dependent on sweating
and its evaporation, anhydrotic horses are prime candidates for heat stress.
It's important to know if your horse falls at risk due to this condition,
and take proper precautions to protect it from overheating. When you work
or exercise your horse in hot weather, watch carefully for the signs of
"Heat Stroke" which can include; skin that is dry and hot, a pulse and respiratory
rates much higher than normal and unusually high rectal temperatures. "Heat
stroke is life threatening," If you suspect that your horse is suffering
from heat stroke, call your veterinarian immediately! While you are waiting
for your vet, move the horse to a shady area with fans or wind to provide
cool ventilation. Spray cool water on the horses legs and body to help lower
the internal temprature. In critical situations, ice packs or cold water
soaked towels should be placed on legs and other areas that exhibit large
veins surfaced on the horse. (if cold towels are used, make sure to change
them often because the horses extreme heat will quickly turn the cold water
hot) Normally, a horse's rectal temperature is around 101 degrees fahrenheit,
if the rectal temprature is around 104 degrees for any length of time, it
is characteristic of a life-threatening situation. When a horse is suffering
from heat stress, stop working the horse and begin cooling the animal's
body with fans and shade to help stop the onset of heat stroke. Also, pay
careful attention to make sure that the horse doesn't become dehydrated
during long bouts of exercise, large amounts of fluid can be lost through
sweat. In most cases, horses should be allowed to drink as often as they
desire, even during exercise, unless they are showing signs of heat stress.
A "hot" horse has the chance to colic if given lots of water while they
are hot. Small amounts of water should be offered to the horse in frequent
intervals before, during and after exercise. A simple test that can be used
to determine marginal water loss in a horse is the pinch test. When a section
of skin on the neck or shoulder is pinched, the skin recoil will be immediate
in normally hydrated horses. Dehydration will delay skin recoil. It is important
to make sure the horse is properly cooled-down following exercise work-outs.
The built up heat must be released from the horse's body through respiration
and sweat. Heat loss through sweat requires moving air and evaporation.
Walking a hot horse allows the air movement to continue to help evaporate
heat, if left standing still, the lack of air movement could force the internal
temprature to rise even higher. Air flow is vital to remove heat off the
horse's body. The length of cool-down will depend on the amount of work,
the environmental conditions and the individual horse. Horse owners who
know the signs of heat stress in horses can help prevent heat stroke in
their animals, so becomming aware, can reduce the chance of injury, or even
worse, death. If you use common sense and good judgement, this all can be
avoided, so watch for the signs!
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From About.com,
Veterinary Medicine:
Canine Heat
Stress
Time to get out with the family (and likely a family pet or two) and
enjoy recreational activities. The purpose of this article is to serve
as a reminder of summer dangers for pets, so that all of the fun isn't
spoiled by an unsuspected emergency or illness.
Heat Stroke Most people are aware that leaving a pet in a locked car on
a 100F degree day would be dangerous. However, it is the seemingly mild
days of spring (and fall) that pose great danger, too. Driving around,
parking, and leaving your pet in the car for "just a minute" can be deadly.
A 70-80 F degree day can heat up the interior of a car to 120-130 F degrees
in 30 minutes or less - even with the windows cracked.
Jogging is also dangerous this time of year. So your dog jogs everyday
with you and is in excellent shape - why alter the routine? As the weather
warms, humans alter the type and amount of clothing worn, and we sweat
more. Dogs are still jogging in their winter coat (or a slightly lighter
version) and can only cool themselves by panting and a small amount of
sweating through the foot pads. Not enough! Many dogs, especially the
'athletes' will keep running, no matter what, to stay up with their owner.
Change the routine to early morning or late evening to prevent heat stroke.
Consider your pet's housing. If they are kept outdoors, do they have shade
and fresh water access at all times? I have treated one case of heat stroke
in a dog that did indeed have shade and water while tethered under a deck,
but had gotten the chain stuck around a stake in the middle of the yard
-- no water or shade for hours. If you live in a warm climate, it is a
good idea to hose down the dog before work, at lunch or whenever you can
to provide extra cooling (if you dog is not over heated in the first place).
Signs of heat stroke include (but are not limited to): body temperatures
of 104-110F degrees, excessive panting, dark or bright red tongue and
gums, staggering, stupor, seizures, bloody diarrhea or vomiting, coma,
death. Brachycephalic breeds (the short-nosed breeds, such as Bulldogs
and Pugs), large heavy-coated breeds, and those dogs with heart or respiratory
problems are more at risk for heat stroke.
If you suspect heat stroke in your pet, seek Veterinary attention immediately!
Use cool water, not ice water, to cool your pet. (Very cold water will
cause constriction of the blood vessels and impede cooling.) Do not aid
cooling below 103 F degrees - some animals can actually get HYPOthermic,
too cold. Offer ice cubes for the animal to lick on until you can reach
your Veterinarian. Just because your animal is cooled and "appears" OK,
do NOT assume everything is fine. Internal organs such as liver, kidneys,
brain, etc., are definitely affected by the body temperature elevation,
and blood tests and veterinary examination are needed to assess this.
There is also a blood problem, called DIC (Disseminated Intravascular
Coagulation) that can be a secondary complication to heat stroke that
can be fatal.
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Symptoms
Give Warning of Heat Stress in Horses
Courtesy of Oklahoma State University
Article by Donald Stotts |
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Symptoms Give Warning of Heat Stress in Horses Courtesy of
Oklahoma State University Article by Donald Stotts STILLWATER - Daytime
temperatures for Oklahoma are soaring upward into the 90s and approaching
100 degrees Fahrenheit; that means horse owners will need to monitor their
animals closely. Heat is produced as a normal by-product in the daily metabolic
processes of horses, said Dave Freeman, Oklahoma State University Extension
equine specialist. During exercise, there is a significant increase in the
amount of heat produced by working muscles. Heat production estimates can
increase as much as 50 percent during periods of intense exercise as compared
with heat production when the horse is at rest. In response, a horse increases
its sweating rate, moves more blood to the capillaries under the skin and
increases its rate of breathing in an effort to release this build-up of
heat. "Heat stress from exercise can result when the environmental temperature
is high," Freeman said. Commonly observed signs of heat stress are profuse
sweating, rapid breathing rate and rapid heart rate. Furthermore, some horses
are anhydrotic, meaning they have little or no ability to produce sweat.
Since heat loss is mainly dependent on convection (wind) and evaporation
(sweating), anhydrotic horses are prime candidates for heat stress. Freeman
said heat stroke can progress rapidly from heat stress if work intensity,
environmental temperature, humidity or anhydrosis overloads the horse's
ability to cool itself. Symptoms include skin that is dry and hot, pulse
and respiratory rates much higher than normal and unusually high rectal
temperatures. "Heat stroke is life threatening," said Freeman. "The owner
should call an equine veterinarian immediately." Freeman said the horse
should be moved to a shady area with fans or wind to provide ventilation.
Cool water should be sprayed on the legs of the animal's body to help the
evaporation process. "In critical situations, ice packs should be placed
on legs and other areas that exhibit large veins surfaced on the horse,"
Freeman said.Veterinarians normally will give large amounts of fluid to
the animal, and possibly give cold water enemas or drenches if the core
temperature is extremely high. "Normally, a horse's rectal temperature is
around 101 degrees Fahrenheit," Freeman said. "The critical temperature,
one that is characteristic of a life-threatening situation if maintained
for any length of time, is around 104 degrees Fahrenheit." The best recommendation
is for equine owners to know how to identify heat stress in a horse before
it progresses to heat stroke. Relieving the horse from exercise and cooling
the animal's body by fans and shade will help stop the onset of heat stroke.
"Also, care must be taken that the horse doesn't become dehydrated during
long bouts of exercise," Freeman said. "Large amounts of fluid can be lost
through sweat." Freeman said the long-accepted practice of restricting drinking
water to exercising horses has little scientific backing. "Generally, horses
should be allowed to drink as frequently as they desire, even during periods
of exercise, unless they are showing definite signs of heat stress," he
said. A hot horse may colic if given large amounts of water; since horses
should not drink large amounts when they are hot, riders should offer small
amounts of water to the horse in frequent intervals before, during and after
exercise. A simple test that can be used to determine marginal water loss
in a horse is the pinch test. When a section of skin on the neck or shoulder
is pinched, the skin recoil will be immediate in normally hydrated horses.
Dehydration will delay skin recoil. Another practical test is the "effective
temperature" test, used to help determine the environmental conditions most
likely to result in heat related illness in an exercising horse. This test
combines ambient temperature with relative humidity. "When the sum of the
ambient temperature in degrees Fahrenheit and the relative humidity is around
150, the rider should use caution in exercising the horse so heat build-up
doesn't become critical," Freeman said. Most riding activities involving
long or intense exercise should be postponed when figures approach 180.
Finally, it is important not to overlook cool-down periods following exercise
bouts, even when environmental temperatures are well within normal parameters,
Freeman said. "Large amounts of heat build up in a horse during work," he
said. "This heat must be released from the horse's body through respiration
and sweat." Heat loss through sweat requires convection and evaporation.
Freeman said the commonly used practice of walking a hot horse guards against
placing it in an area void of air flow. "Air flow is vitally important for
convection of heat off the horse's body," Freeman said. The length of cool-down
procedures will depend on the amount of work, the environmental conditions
and the individual horse. Freeman said horse owners who use these simple
procedures and who know the signs of heat stress in horses can help prevent
heat stroke in their animals.
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Thursday, June 3, 1999
Heat's
hard on pets
By LINDSAY TOZER Staff Writer
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You're sitting in an unventilated car, unable to roll down
the windows or open the door. It is 97 degrees outside, and you're wearing
fur. It's a dog's day of summer. The best case scenario finds the pet panting;
the worst case finds the animal staggering, his heart racing, until he collapses
into a coma, said Abilene veterinarian Elizabeth King. Confinement is more
dangerous than people think, she said - Society for the Prevention of Cruelty
to Animal officials have likened a car parked in the sun to a furnace -
with the intense heat causing organ damage. Even mild dehydration affects
kidneys, King said, and heat stroke can scar the liver and heart. Initially,
signs of heat stroke might be subtle - an increase in panting or a change
in gum color - but the trouble they signify can kill an animal. Something
as simple as excessive drooling that suddenly stops may not mean your dog
has adapted to the heat, the veterinarian said, but might indicate advanced
dehydration. About 50 percent of owners who bring their pets to King recognize
the symptoms as being related to the weather, she said. Older dogs, puppies
and obese animals can be more susceptible to heat-related problems. "There
was a dog last summer who developed heat stroke in the same shady yard he'd
always been in," she said. "The difference was, now he was 17 years old."
Cats left in parked cars account for a majority of the feline heat stroke
cases King sees. "Even a minute or two stuck in the car while you're standing
in line at Skinny's is too long," she said, though cats have suffered from
being trapped in closed garages and sheds. Dousing a pet with cool, but
not ice cold, water and contacting a veterinarian, King said, is crucial
for those owners who suspect their animals have developed heat stroke. The
number one pet priority for hot summer months is cool, clean water and lots
of it, she said. Keeping animals inside, if at all possible, is ideal during
the summer months. According to the National Weather Service, temperatures
should hover in the mid-90s through the weekend. Rationalizing that Abilene
summers aren't particularly humid isn't enough, King said. "If it gets hot
enough, dry heat can kill as quickly as wet heat," she said. "We think it
is more comfortable because we can sweat it off, but dogs and cats can't
sweat enough to make a difference." If keeping a pet indoors is not an option,
a shady yard and a kiddie pool filled with a few inches of water can keep
a dog cool, said Beverly McCallon, a Taylor-Jones Humane Society volunteer.
In hot weather, walks should be kept to a minimum, according to the ASPCA.
With the dogs bodies being so low to the ground, the hot asphalt can make
their bodies can heat up quickly. Ditto for transporting dogs in the back
of pick-ups, McCallon said. "The metal and the black bedliners could burn
their paws," she said. At home, pay attention to where the shade is and
how your pet reacts when he's outside, King said. "What happens on the weekends
is what happens when you're at work," she said. Apartment dwellers or those
without a fenced-in yard tackle special issues. Although many apartment
communities around Abilene prohibit leaving a pet outside unsupervised,
a few, including Curry Junction management, said they've dealt with cases
of owners leaving their dogs on porches or patios during the workday. The
veterinarian doesn't mince words about those who can not sufficiently service
the needs of their pets during the summer months. "You need to think about
that before you get a pet," she advised. "A dog put on a short chain or
in a cage, you need to find a new home for you or for your pet, period."
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