While Martingale dog collars can be somewhat hard to find, custom martingale dog collars are nearly impossible!  You’ve found them both here.  Martingale collars are special made for walking and training greyhounds. Sometimes referred to as greyhound collars, they have an extra loop that gently tightens the collar if the animal pulls, so that the collar cannot easily slip off. Choose your Martingale collar with or without custom embroidery.