How Hypertrophic Cardiomyopathy Affects Dogs
Hypertrophic cardiomyopathy (HCM), which is the most common heart disease seen in cats, is not frequently seen in domestic dogs. When it does occur in dogs, it may not be accompanied by any noticeable symptoms and may only be detected incidentally during a routine veterinary check-up. This suggests that the dog probably is not suffering substantial discomfort or distress due to its condition. Of course, some dogs are particularly stoic and may be feeling poorly without showing signs of their ailment.
Symptoms of Hypertrophic Cardiomyopathy
When dogs do develop clinical signs associated with hypertrophic cardiomyopathy, they typically include one or more of the following:
- Increased respiratory rate (tachypnea; rapid breathing)
- Difficulty breathing (dyspnea; respiratory distress)
- Open mouth breathing (panting)
- Coughing (+/-)
- Lethargy, listlessness
- Lack of appetite (inappetence; anorexia)
- Weight loss
- Acute onset of hindlimb lameness (+/-pain)
- Exercise intolerance (tires easily)
- Sudden death
Dogs at Increased Risk
Hypertrophic cardiomyopathy is most frequently seen in young to middle-aged large breed dogs, but it still is an uncommon canine disorder. Males seem to be affected more often than females, although both genders are susceptible. Rottweilers, Dalmatians, German Shepherd Dogs, Boston Terriers and certain Pointers reportedly have an increased risk of developing HCM. The reasons for these apparent associations are not clear.