Thursday, May 15, 2008

Off Season Conditioning - Watch for Heat Stroke


It is important to note that like any athlete, running sighthounds need to stay in condition all year. It is not practical to just shut them in a kennel at the end of the hunt season and forget they exist until next fall and expect them to come out of isolation and hunt the way you want them to. Early morning, sometimes predawn runs to help keep them fit or early evening when the outside temperatures get below 70 degrees F, are best. If you are in a part of the country where it never gets below 70 or 80 degrees all spring/summer, then you need to keep the runs short and have a water source close at hand so the hounds can cool off sufficiently. I had an occasion where I was coursing some hares on BLM land in Wyoming in the Spring of '06. It was later in the morning and the sun was shining. An absolutely beautiful day actually. The problem was that the temperature had climbed just above 60 degrees F. We were walking back to our trucks and the hounds flushed a hare. My white hound, Mace was all over this hare and it was quite an exciting course. It took them up and over a hill approximately 1/2 mile from me. Mace came back within a few minutes but was looking and acting disoriented. She was panting excessively hard and was having a difficult time standing. I knew at once that she had overheated herself and began looking for a way to cool her down. I took all the remaining water I was carrying and poured it over her mouth and on her belly but there just was not enough. I raced around trying to find a little puddle of water in a fairly arid place. I was fortunate to locate one and carried Mace to it as she was not walking well. I sat her down in the muddy water and within about 20 minutes she seemed to be feeling better. This could have been a much more serious problem with a bad outcome if I had not found a way to cool her off. I have known a number of people to loose good hounds during warm weather to this condition. The following description was written by Dr. Dunn, DVM. My hope is that this article provide a way to avoid this condition or if it should occur, a way to cure this before an avoidable tragic loss of a valuable hound happens.

WHAT IS HEAT STROKE

Living cells have temperature tolerance limits. Go beyond those limits and the cell breaks down, looses functional capacity, releases chemicals within itself that cause more adverse reactions, and eventually ceases to function and dies. Tolerance to higher than optimum temperatures for mammals breaks down at about 107 degrees. And the death of the cell (that state where the traumatized cell cannot recover from the heat injury) occurs when time and temperature factors combine to terminate the cell's integrity. The longer the cell is above the 107 degree level the less chance there is for the cell to recover. The higher the temperature becomes above 107 degrees the faster the cell death occurs. In pets confined to a space where the ambient (surrounding) temperature and humidity are above tolerable levels the animal's body will begin to acquire heat from the environment faster than it can dissipate that heat. In overheated humans we begin to sweat, which evaporates (unless the humidity is 100 percent), and cools the skin surface and assists in dissipating that heat buildup. In fur covered dogs and cats that have very few sweat glands to begin with the only means of dissipating excess body heat is via panting. This movement of air over the moist tongue and airway surfaces increases evaporative cooling (again, unless the ambient humidity is 100 percent). Unfortunately, panting is a rather inefficient means of dissipating body heat and actually generates some heat due to the muscle activity involved. Keep in mind that as an animal is confined to a closed space the expired air, which is at 100 percent humidity and 102 degrees, will eventually increase the ambient humidity and temperature of the animal's space. Plus, especially with larger animals such as Great Danes and St. Bernards, their body heat will increase the ambient temperature in the vehicle. It should be readily obvious that leaving an animal in an enclosed space, even if the vehicle is in the shade and even if the outside temperature is only in the seventies, will cause a buildup of temperature and humidity in that vehicle. Time and temperature and humidity are critical factors in the development of heat stroke in pets. And once the animal's cells reach 107 degrees it is crucial for any chance of recovery to lower that temperature as fast as possible. Otherwise death will result no matter what you do to try to save the animal.

SIGNS OF HEAT STROKE

Signs of heat stroke are intense, rapid panting, wide eyes, salivating, staggering and weakness. Advanced heat stroke victims will collapse and become unconscious. The gums will appear pale and dry. If heat stroke is suspected and you can take the animal's temperature rectally, any temperature above 106 degrees is dangerous. The longer the temperature remains at or above 106 degrees the more serious the situation. If you return to your car or the area in which the animal was confined and find your pet seems to be highly agitated, wide-eyed and panting uncontrollably... start for the nearest animal hospital right away with the air conditioning at full blast. Otherwise get the dog to a cool area and begin the treatment for heat stroke.

TREATMENT FOR HEAT STROKE

Take the pet's temperature rectally if possible. A body temperature of about 105 degrees or higher is probable evidence for heat stroke. Place your pet in a tub of cool running water or spray with a hose being sure the cool water contacts the skin and doesn't simply run off the coat. Thoroughly wet the belly and inside the legs. Run the cool water over the tongue and mouth. Take a rectal temperature if possible to know when to stop cooling. A safe temperature is about 103 degrees. A small dog will cool down much faster than a large dog. Once the temperature gets to 103 or 104 degrees do not cool the pet any further because the cooling effects will continue to bring the temperature down even further. Seek veterinary attention as soon as possible.
If you are near an animal hospital, go there right away. At the animal hospital they may administer oxygen, cortisone and dextrose to help protect the traumatized cells. The staff can provide proper cooling measures and monitor the dog's temperature, heart rate and provide oxygen which some evidence indicates may help protect stressed body cells. Providing intravenous fluids and anticoagulants may be utilized as well.

WHAT DOES HEAT STROKE DO?

In severe cases, the elevated body temperature triggers chemical reactions in the cells of the body... highly active cells such as brain, intestinal and liver cells are at greatest risk for heat trauma. The metabolic disturbances brought on by excessive heat instigate the release of chemicals within the cells that cause the ultimate destruction a breakage of the cell. Most heat stroke victims are dehydrates, as well, and their blood thickens to the point that the heart has severe stresses placed on it in trying to pump the abnormally viscous blood through the blood vessels. The result is stagnation of blood, blood clotting and eventual death of tissues due to what is termed ischemic necrosis. Wherever a clot forms, the tissues nourished by that clogged vessel die from metabolic starvation. The dying cells give off chemicals that further damage surrounding tissues and a point is reached beyond which no recovery is possible. In some unfortunate situations where the heat stroke victim has experienced a dangerously high body temperature for a length of time such that too many brain and other body cells have been damaged, no matter what life saving measures are employed and bioprotective medications are administered, death will result.

FINAL THOUGHTS

This is a serious condition which you need to be aware of not only while hunting your hounds but there are a lot of people that participate in other forms of recreation with their running hounds like lure coursing or even playing in a dog park. Traveling with your hound, even on short trips where you make a quick stop for coffee or a drink. Be aware of the temperatures your hounds will be subjected to. Become familiar with the symptoms of Heat Stroke and get treatment to help a dog in distress very quickly. Their lives will depend on it and on you to help them.

2 comments:

nikhil said...

for hunting dogs i fail to understand why instead of using greyhound or deer hound we don't use the asawakh or mudhol hound which has a very high heat tolarence. even the salukis of arabia are better than using a greyhound cross.

Mike Bilbo said...

Nikhil,
Thanks for the comments. I have not heard of the Mudhol Hounds and the Azawakh are very difficult to fine here in the US. Salukis lack size and speed to course the coyotes and most of our hunting is done in winter or cooler weather. I would be interested to see these hounds work but have never seen either of them in the field.