Overheating, or heat stroke, is a common problem in hunting dogs, and as we found out during South Dakota's pheasant opener last year, a deadly problem as well. Overheating is a condition that develops from the body's inability to regulate temperature. Basically, the heat being produced by the body is greater than the heat being dissipated. The causes of heat stroke in hunting dogs are numerous, but at the top of the list is a lack of conditioning. Too many guys take their dogs from the couch or the kennel straight into the field without any thought about the dog's level of conditioning. This would be akin to taking most of us on a given day and demanding us to run a marathon at the drop of the hat. The difference is that we're able to say no and are in tune with our bodies enough to know when to stop. These dogs love to hunt and love to perform, and by the time they are showing signs of a problem it is often too late. Other causes of overheating include lack of acclimatization, high humidity and high temperatures. A rule of thumb used by many dog trainers down south is that if the ambient temperature when added to the humidity is greater than 150, you probably shouldn't be running your dogs. You can still have heat

stroke develop at lower temps, but this is when it becomes particularly dangerous. You'll also see heat problems with too much exercise too soon. Also an obese animal is going to be much more prone to overheating than one running at a lean body weight. Previous episodes of overheating will also predispose a dog to overheating again, because overheating can cause the body's internal thermometer to become "out of whack" and make the dog more susceptible to future episodes. It's also important to know a dog in water can still have heat stroke. This is particularly true in the summer months and early fall when many of the shallow bodies of water have had time to heat up. At these times it can be like swimming the dog in a hot tub. Just because they're wet doesn't mean they're cool. Basically, you should always try to be smart when working your dog in any type of heat. Signs that your dog may be getting close to overheating include panting and/or extreme hyperventilation. These dogs aren't just hot; they are trying to move as much air as possible in an often futile attempt at removing heat. Many of these dogs will also be hypersalivating. They'll come back with long ropes of drool coming out of their mouths, or puddles of saliva around them. They also will have an altered mental state and appear glassy-eyed. Often when you look at these dogs they look like they are in trouble, almost as though no one is home when you look them in the eyes. Many will become ataxic (i.e. stumbling and incoordination) and show muscle weakness. Often, but not always, you will see vomiting and diarrhea develop. From here it may progress to total collapse. At this point you are probably wondering what temperature the body has to reach to fall into the category of heat stroke, and unfortunately there isn't one. The normal body temperature of dogs is 100-102.5 F, but in normal working dogs, without heat stroke, we can have temperatures during and immediately following exercise that get up around 106-107 F without causing a problem. But these are the same temperatures that we start worrying about heat damage starting to occur with heat stroke. This is where having a thermometer in your emergency kit becomes important, because if the temperature does not begin to fall immediately, or worse it continues to climb, after the exercise is stopped, your dog is in trouble. As corny as it may sound, I would recommend taking you dog's temp after a day of hunting or while out training when you are not even close to crossing the overheating line. This will give you an idea at what temp your pup typically runs while at work and will allow some sort of baseline if you get into trouble out in the field. Basically during heat stroke all the body systems are being affected. The tissues of the body are essentially cooking themselves. When we get these dogs into the clinic they have severe blood chemistry abnormalities, they can go into respiratory distress and this is one condition that can quickly lead to death.