Dogs at high risk of developing intolerance to heat are the very young or very old, those who are overweight, those with history of heart or respiratory disease and those who lack exercise. Recommended preventative measures for hot days include limiting exercise, ensuring the dogs have access to cool water and providing air-conditioned or shaded living accommodations. Dogs will show symptoms when they're prone to heat intolerance. Seek immediate veterinary care at the first sign.
Rapid Heart Rate and Excessive Panting
Dogs cool their bodies by panting. It's their natural internal convection cooling system: They exchange their body heat for cooler air with their tongues, bringing their core temperatures down. The exposure to extreme heat or development of heat intolerance will cause panting to increase -- you'll likely become aware of the increased panting due to the sound of labored breathing or panting. When the air the dog is inhaling is equal to or hotter than the dog's temperature, intolerance to heat symptoms may arise. A rapid heart rate develops due to the overheated body working hard to overcome the excessive body heat.
Changes in the Mouth
A highly noticeable change in the mouth is a bright red tongue. Inspect your dog's mouth further after seeing any color change in the tongue. Dehydration can cause dry mouth and the appearance of sticky, thick saliva, and red or pale gums.
Lack of Energy
A dog experiencing intolerance to heat will experience low energy and weakness. Symptoms of low energy include the dog slowing his walking pace, stumbling or attempting to lie down in the middle of an activity. Shaking, trembling, disorientation, dizziness and weakness will appear as his temperature rises and the heat exhaustion becomes more severe.
Diarrhea and Vomiting
Dogs suffering from intolerance to heat may experience frequent diarrhea and vomiting. It will appear suddenly and may occasionally include small amounts of blood. If you observe signs of heat exhaustion, examine your dog's feces and vomit, seeking the evidence of blood. This symptom should be reported to the veterinarian to assist his course of action for treatment and recovery of heat intolerance.
Shock and Coma
In extreme intolerance to heat cases, dogs can experience shock and slip into coma. Shock and coma develop at the later stages of heat intolerance, which may referred to as heat exhaustion, heat stroke and hyperthermia. These conditions are usually avoidable if you take immediate action at the first sign of heat intolerance. Shock and coma are serious health conditions. Signs of heat intolerance should prompt you to rush your dog to the nearest animal shelter or to a licensed veterinarian immediately.