EMS (Electrical muscle stimulation.)
EMS is very similar to a human TENS machine, where a small electrical current is passed into the body. The difference between the two machines is that TENS stimulates nerves to give pain relief and EMS stimulates muscles to create a contraction.
Special pads are stuck to the skin at either end of a muscle, the current is then passed and the muscle contracts. This is the technology used in Slendertone machines. This is a useful way of stopping muscle wasting and can be used even before the animal is able to stand. It is also useful for building muscle when the animal cannot use the muscles themselves particularly after a neurological damage and they cannot get around very well.