numnah or saddle pad

cob/full size normally :)

It could but it'll depend on how broad the ponys' back is.

no but its better for your horse's back otherwise it could get little wounds and scratches.

It could hurt the horse and give them sores and pinch nerves!

A saddle should be able to fit correctly without a pad or numnah under it. It's even recommended that you fit a new saddle without anything under it first to see if it fits the horse properly. A saddle cloth, pad, blanket, or numnah is designed to wick the moisture from the horses back and to provide a little bit of cushion. Some pads have a therapeutic benefit such as wither relief or to lift the saddle. The biggest problems are sores from the saddle rubbing on bare skin and hair, and the saddle itself becoming damaged from the horses sweat.