There are many breeds commonly affected by heart disorders;
Atrioventricular valvular insufficiency
Afghan hounds, American cocker spaniels, Beagles, Bull terriers, Boston terriers, Cavalier King Charles spaniels, Chihuahuas, Dachshunds, Fox terriers, German Shepherds, Great Danes, Japanese Chins, Maltese, Miniature and toy poodles, Miniature schnauzers.
Dilated Cardiomyopathy
Airedales, American and English cocker spaniels, Boxers, Dalmatians, Doberman pinschers, Golden retrievers, Great Danes, Irish wolfhounds, Labrador retrievers, Newfoundlands, Old English sheepdogs, Portuguese water dogs, Saint Bernards, Scottish deerhounds, Springer spaniels
Hypertrophic Cardiomyopathy
Pointers
Your pet may show no sign of heart problems, or you may notice some of the following;
Coughing
Changes in breathing; difficulty breathing, shortness of breath, labored breathing, rapid or fast breathing
Changes in behavior (more noticeable in dogs); tiring easily, reluctance to exercise or not wanting to go fore walks, less playfulness, slowing down or lack of energy, depression or a withdrawn demeanor
Poor appetite
Weight loss
Fainting or collapsing
weakness
Restlessness, especially at night
Swollen abdomen.
Don't assume your pet's behavior is simply a sign of aging. Contact your veterinarian immediately if you notice any of the above.