I always have coats for my greyhounds cos they are skinny and short coated - although I have never had one for my lurcher who is fatter and short coated
The greyhound ones I buy are waterproof with a fur lining, they must be long enough and deep enough to cover the dog properly, and they also have a 'high neck' bit.
and make sure the strap is going to be tight enough especially if you have a boy dog had a wax one but it wasnt warm enough and ive got a plain navy waterproof one for my lurcher but i have the problem with the straps not being tight enough around his tummy which means i got sick of taking a smelly dog coat home and he now has to just run around if he gets cold until i get him another oe lol
It gets very cold over here, so we use a coat that's down-filled. A snug fit is important, as is a nice wide belly covering. The dayglo colour is a groovy bonus