Lisa, "pre-clinical" would be equal to the ACVIM's Stage B1, which refers to "asymptomatic patients that have no radiographic or echocardiographic evidence of cardiac remodeling in response to CVHD."
So, Tillie, with her dilated left atrium, would be beyond pre-clinical. At her stage, I would leave the medication decisions to her cardiologist. Carvedilol may benefit her, but her cardiologist would know enough about it to decide.
Carvedilol is not a new drug, and it is not even new to cavaliers with MVD. It has been given to cavaliers with MVD for at least the past seven years. I think I over-stated the significance of the findings in the Texas A&M report which came out this month. In that report, carvedilol is not so much "successful" as it is "well tolerated".
Orlando, Florida USA