Serotonin's role in mitral valve disease Jul 27, 2009 By dvm360.com staff A new study has found that in dogs and people with naturally occurring mitral valve disease, diseased cells within the heart are producing serotonin, contributing to valve degeneration. Click here to read more. Hot topics on dvm3605 ways to wow pet owners (and pets) 10 steps to take when a practice owner dies dvm360 sits down with Dr. Pol Ack! How do you spell that again? "Best. Veterinary Practice. EVER."