Effects of Emphysema
Dogs with emphysema may show no observable signs of illness. When visible symptoms do occur, they may come on suddenly, slowly or intermittently. The exact mechanisms leading to the abnormal accumulation of air in respiratory tissues are not well understood. However, it is suspected that inflammation, physical pressure and other as yet unknown forces cause disruption and breakdown of essential lung tissues, which in turn causes inhaled air to be diverted to and accumulate in abnormal places. It is thought that this is what leads to the respiratory difficulties so commonly associated with emphysema, both in our canine companions as well as in people. The particular consequences of emphysema depend upon exactly where the air builds up, and what organs or tissues that the accumulated air puts undue pressure upon.
Symptoms of Emphysema
When clinical signs of emphysema are present, the affected dog may show one or more of the following symptoms:
- Loss of appetite (inappetence; anorexia)
- Weight loss
- Respiratory distress (labored breathing; difficulty breathing; dyspnea)
- Increased heart rate (tachycardia)
- Increased respiratory rate (tachypnea)
- Exercise intolerance
The respiratory symptoms of emphysema can become extremely severe, requiring hospitalization on an emergency basis.
Dogs at Increased Risk
Emphysema is seen most commonly in middle-aged dogs, although dogs of any age can be affected. There is no consistently reported breed or gender predisposition to developing this disease. However, the Pekingese seems prone to congenital lung lobe emphysema secondary to undeveloped or underdeveloped bronchi (large airways), which causes the airways to collapse partially when the dog exhales, leading to air trapping within the lungs.