Grade 1
Incredibly soft and barely noticeable
Grade 2
Very soft but easily diagnosed when listening through a stethoscope
Grade 3
Moderate dog heart murmur that is easily heard but lacks any vibration when the vets hand is placed on the dog’s chest
Grade 4
Loud with no noticeable vibration
Grade 5
Loud with some vibration but cannot be heard without the stethoscope
Grade 6
Loud with severe vibration and the vet can hear it without a stethoscope