Some Hot Weather Lure Coursing Tips
by Bonnie Dalzell
May 31, 1995
Hot weather coursing is very tricky as heat exhaustion is one of the
major things limiting athletic performance in dogs. They can build up an
enormous amount of heat in the 60 seconds that a course lasts and if
there is a break in the course and they stand around in the sun before
being rerun you can have a dog go into heat stroke.
There are several important physiological factors to understand
* Heat is lost from a body by evaporation, radiation and convection (mass
Sweating cools you by evaporation
Glowing white hot and cooling to red hot would cool something by
radiation - this is not particularly applicable to most animals as we
know them. However black animals re-radiate heat better than white animals.
Being submerged in cold water, having a breeze blow on you or having
water from a hose run over you are all ways of having convective cooling.
If it is very humid then evaporative cooling is relative ineffective
and convective cooling becomes the most important mode.
* Dogs do not sweat to cool off. They get rid of heat by panting and
submerging in water. After they submerge they can get out of the water
and loose heat as the water evaporates but they will need to submerge
again to restore a water film once they dry off.
* the ability to generate heat is proportional to the dog's body mass
* the ability to cool off is proportional to surface areas:
tongue, ears, inside of mouth, lung surface, legs and the rest of the body.
Since mass increases geometrically but surface area increases
arithmetically larger and bulkier dogs overheat MUCH more easily than
smaller and thinner dogs.
In practical terms. If you have a large dog or a hairy dog just misting
its coat with a spray of water from a mister on a hot humid day is NOT
going to cool the dog off. Neither is allowing it to drink a lot of water.
The dog needs to be submerged or hosed down and it needs to be in the
shade. If the dog has just run it should be walked to aid in cooling but
this does not substitute for hosing down or submerging.
Since dogs obtain a fair amount of evaporative cooling through heavy
panting the dog's mouth can be moistened.
A hot dog should not stand around in a muzzle. The muzzle can seriously
interfere with panting.
Dogs in heat stroke may feel clammy to the touch. While going into
heatstroke they may produce copious quantities of thick, ropey saliva.
Seizures can be a consequence of heat stroke.
Dogs are more sensitive to heat and high humidity than humans. A
situation that may be merely very uncomfortable for you may kill your dog.
Dogs take longer to acclimate to climatic changes involving increased
heat and humidity than people and they will loose that acclimation over a
period of cool weather. Just because your Borzoi or Irish Wolfhound was
fine last summer does not mean that you can take it out and run it for
the first time THIS year at a July trial in Florida!
Judges at lure coursing events should keep in mind that the larger and
faster breeds are much more susceptable to heat stroke than small breeds
and deport themselves accordingly in relation to reruns and starting
Field trial committees should strive to allow 20 minutes between runs
for any given dog (as is the case in reruns and a Best of Breed of Best
In Field following a run off).
Remember the purpose of the sport is to test the athletic ability of the
dogs but not to test it to destruction!
In my opinion mid summer trials should have copious shade
available or be limited to Basenjis, Pharaoh Hounds and Ibizan Hounds.
I think it is quite thoughtless of field trial committees to put on a hot
weather, humid climate trial in one of these low lying, treeless, flat
fields with no water and then absolve themselves of responsibility to the
dogs by saying "contestants should bring their own shade and water".
Hot weather dry climate trials (as in the summer in Colorado) are not
particularly hard on the dogs. It is the humidity that kills.
Dogs can get heat stroke in 80 degree weather if it is humid enough.
Bonnie Dalzell, MA
freelance anatomist, vertebrate paleontologist, writer, illustrator, dog
breeder, computer hacker and iconoclast
mail: 5100 Hydes Rd
Hydes MD USA 21082
phone: 410 592 5512