Unlike exposure to other toxins, many Agent Orange symptoms tend to take several years to decades to present, and can cause a host of health issues. Initial symptoms tend to include common side effects found with many other illnesses, as well as neurological and psychological problems.
Heavy breathing or panting. Most dogs will pant from time to time because they are stressed or excited, but when dogs pant for no apparent reason and the panting becomes excessive, this can definitely be a sign that a dog is experiencing pain.
Common Causes of Panting in Dogs. Heat Stroke. Heat stroke is perhaps one of the most common causes of heavy dog panting that can lead to devastating damage to the dog's physical health. If a dog is left in a parked car on a hot summer day, or has been out playing or running for a long time in the heat, he can easily get heat stroke.