9 June 2007
Take a measuring tape and wrap the tape around your dog's neck.
Place two of your fingers between your dog's neck and the tape and take the measurement - most pet collar sizes on eBay (and in shops) are stated in inches. After wearing a new collar for a few while, check your dog's neck to see if your dog has any redness or hair loss under the dog collar, as you may need to adjust it.
If you have a puppy, it is important that you check the collar more regularly to see if your puppy has outgrown it - otherwise the collar could dig into the neck and cause bleeding.