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 dvm360Pet Owner 2.0: A dvm360 Leadership Challenge Veterinary issues in 2016: Will this be the year of telemedicine? Top 8 nastiest things to clean at a veterinary practice The 12 days of veterinary client handouts Need a urine sample? Urine luck!