During the first hour of the program, we will discuss the most common cardiomyopathy seen in dogs: a dilated cardiomyopathy (DCM) phenotype. We will explore the use of the term ‘phenotype’ and the differences between primary DCM and secondary DCM. We will also discuss how primary and secondary DCM affects treatment and prognosis. The second hour of the program will focus on the most common cardiomyopathy seen in cats: a hypertrophic cardiomyopathy (HCM) phenotype. We will discuss primary vs. secondary HCM in cats as well as treatment and prognosis.