Enlarged Heart Treatment More Condition_symptoms Enlarged Heart???

Enlarged Heart??? - enlarged heart treatment more condition_symptoms

I am open to learning!
Iv heard a lot about "enlarged heart" in small breeds and ....... such
But I have no idea what it is, I can go to know the Google search and get the doctors and everything, but I ask people who have experience with this or someone, a dog has an enlarged heart. What is the cause? Getting a dog from an enlarged heart? What are the treatments? Only in small breeds? What are the symptoms? and last but not least of which is an enlarged heart (dog)

Thank you.
We have 3 Chihuahua, if you just want to offer.
= D