Cardiomyopathy is a term used to describe a condition which occurs to the heart muscle, when one or more diseases cause inflammation and scarring.  This inflammation and scarring causes an enlargement of the heart itself, and the chambers within the heart dilate and become less efficient in supplying the body and organs with blood.  The end result of a dog suffering from this condition is that the heart muscle will eventually weaken and the dog will develop congestive heart failure, and will die.
     The articles that the author used in researching this condition stated that the reason dogs develop this condition is unknown, but assumed to be genetic.  Exactly how it is inherited is not yet documented, however, the disease appears to be very breed specific. There are some mixed breeds of dogs that have been diagnosed with this condition, but it is extremely rare.  The breeds of dog that have documented histories of cardiomyopathy are:  Boxers, Cocker Spaniels, Doberman Pinschers, German Shepherd Dogs, Golden Retrievers, Great Danes, Irish Wolfhounds and Saint Bernards.
     Doberman Pinschers have been most often used in the medical research on this condition.  It is important to realise that a dog does not react to illnesses like a human will.  The clinical signs of a dog suffering from cardiomyopathy do not appear over a long period of time.  The signs often appear over a few days, when in reality, the disease starts at an early age, between two and five years of age.  Researchers have discovered that male dogs are asymtomatic until the disease becomes severe, sometime between five and eight years of age.  Female dogs are often asymtomatic until they are between nine and twelve years of age.  Once the clinical signs appear the dog may already be in the stage of severe heart failure.
     The following symptoms may indicate a developing heart problem.  They could also indicate other conditions as well, only a visit to the dog’s veterinarian for examination can determine what exactly the problem may be.  The symptoms can occur with surprising rapidity, making the involvement with a veterinarian imperative as this condition is life-threatening.
     Observe your animal for unexplained lethargy, weight loss, cough, exercise intolerance, and shortness of breath.  Cardiac arrhythmias may cause fainting.  If your dog is showing one or more of these problems, get him/her to a veterinarian.