After Exercising

• Dogs pant hard after running or exercising. This is due to the dog's excitement combined with the fact that the dog's heart rate and body temperature increase. Dogs don't sweat and panting is the way they release heat. Allow your dog to rest if it pants heavily after exercising. Avoid exercising your pet during periods with extreme heat in the summer to prevent heat strokes.
  
  

Excessive Heat

• A dog that spends time in the sun or is kept in a hot room is likely to pant hard. If the body temperature of the pet increases above 105 F, the dog is prone to a heat stroke. Puppies, senior and overweight dogs develop heat strokes more easily. A heat stroke is a severe condition that causes lethargy, weakness, vomiting and in extreme cases, seizures, collapse and coma. Keep your dog in the shade or indoors during periods of extreme heat and never leave it in a car that is parked in the sun during summer.
  
  

Respiratory Problems

• Brachycephalic pets such as bulldogs, Boston terriers or pugs have a shorter nose and may have difficulty breathing through the nose in certain situations, so they pant often. However, excessive panting may be a sign that the dog is affected by a respiratory problem such as lung disease, polyps or tumors in the respiratory tract or the chest cavity, pneumonia and collapsed trachea. Tests are required to detect any respiratory problems that cause panting.
  
  

Heart Problems

• Your dog may be panting hard due to a heart failure or a blood clot in the area. Additional symptoms that may point to a heart problem include exercise intolerance and coughing. Heartworm disease may also cause breathing difficulties and panting. The parasites occupy the vessels in the lungs and the dog cannot breathe normally.
  
  

Other Causes of Heavy Panting

• Heavy panting may be a side effect of certain medication treatments such as Prednisone. Other potential factors causing panting include fear, poisoning, anemia or fluid accumulation in the abdominal cavity. Dogs often signal pain through heavy panting. Look for additional symptoms in your pet such as visible wounds, excessive licking of certain areas, discolored gums, pawing the mouth or other areas of the body, lack of appetite and dilated pupils. Visit the veterinarian to get a diagnosis and timely treatment.