Too much fast work on hard ground causes the navicular bone (in horses hooves) to swell up..usual remedy is to put them on painkillers for rest of their time. Though it is a good sound
another sound i almost forgot is cat purrs..thoughts of my old fat cat's purr lulling me to sleep spring to mind and more recently the silly purr of a certain black and white cat i've gone all soft on
There's something very comforting and reassuring about a cat's purr.