Dogs come in many different sizes and so do their collars. The perfect collar for your dog is one that fits properly. You can buy a designer collar, preppy collar, or even a cool collar, but if it is not the right size, then it is not the perfect collar for your dog. A collar that is too small will cause your dog to be uncomfortable and one that is too big may put him in danger.
To find the perfect collar for your dog, measure his neck where the collar would sit with a soft tape measure. If you do not have one, use a piece of string and simply measure the string. Once you have measured around your dog's neck, add two inches, you now have your dog's neck size.
Check your new collar by trying it on your dog. It should be snug, but there should be room for you to slide two fingers between your dog's neck and the collar. Your dog should be comfortable wearing his collar and at no time should it be too tight or too loose.
Most dogs wear one of four sized collars; Small, Medium, Large or X-Large. Puppies may go through a few sizes as they grow, especially large breed puppies. Your dog may gain or lose weight over time and it is up to you to see that he is wearing the perfect dog collar.