Changes

Degenerative mitral valve disease tends to affect middle-aged and older dogs, with males being predisposed. The disease more commonly affects small breed dogs, with Cavalier King Charles Spaniels, Chihuahuas, Boston Terriers, Poodles, Pomeranians and Bull Terriers being predisposed. The disease is also recognized in large breed dogs.  

Degenerative mitral valve disease tends to affect middle-aged and older dogs, with males being predisposed. The disease more commonly affects small breed dogs, with Cavalier King Charles Spaniels, Chihuahuas, Boston Terriers, Poodles, Pomeranians and Bull Terriers being predisposed. The disease is also recognized in large breed dogs.  

===History===

==History==

Animals may remain asymptomatic for years. Typical reported signs include exercise intolerance and dyspnoea as a result of reduced cardiac output and a ventilation perfusion mismatch due to pulmonary oedema. A progressive cough often during rest or recumbency is frequently seen and needs to be distinguished from primary respiratory disease. Sudden death is possible due to a left atrial tear or advanced pulmonary oedema.

Animals may remain asymptomatic for years. Typical reported signs include exercise intolerance and dyspnoea as a result of reduced cardiac output and a ventilation perfusion mismatch due to pulmonary oedema. A progressive cough often during rest or recumbency is frequently seen and needs to be distinguished from primary respiratory disease. Sudden death is possible due to a left atrial tear or advanced pulmonary oedema.