Hypertrophic cardiomyopathy in the dog

Area of Science:

• Veterinary Cardiology
• Comparative Pathology

Background:

• Hypertrophic cardiomyopathy (HCM) is a primary cardiac disease characterized by myocardial hypertrophy.
• Understanding spontaneous HCM in animals can provide comparative models for human disease.

Purpose of the Study:

• To describe the clinical and necropsy findings in dogs with spontaneous primary hypertrophic cardiomyopathy.
• To evaluate the utility of canine HCM as a model for human HCM research.

Main Methods:

• Clinical and necropsy examinations were performed on 10 dogs diagnosed with spontaneous primary hypertrophic cardiomyopathy.
• Cardiac hypertrophy and ventricular septal thickening were assessed, including septal:free wall thickness ratios.

Main Results:

• All 10 dogs exhibited marked cardiac hypertrophy, with 8 showing disproportionate thickening of the ventricular septum.
• Cardiac muscle cell disorganization, typical of HCM, was found in only 2 dogs.
• Common causes of death included anesthesia during procedures (5 dogs) and sudden death (3 dogs).
• Congestive heart failure was observed in 4 dogs, and complete heart block occurred in 3 dogs.

Conclusions:

• Spontaneous primary hypertrophic cardiomyopathy in dogs presents with significant cardiac hypertrophy and specific septal thickening patterns.
• The pathological findings, while showing some similarities, also present differences compared to human HCM.
• Canine spontaneous HCM warrants further investigation as a potential model for studying human hypertrophic cardiomyopathy.