|A collar should rest high on your pet's neck without fitting too loosely. Use a tape measurer to measure around your pet's neck. Add on 2 more inches to determine the correct collar you should buy.
For chain-slip collars, you want to avoid having too much or too little slack, or you will diminish the effectiveness of the correction. Measure your pet's neck and add another 2 "-3" to determine the collar size. Use a fast 'pop and release' to correct with this collar.
For a pronged collar, measure around the dog's neck just below the ears. Use this measurement to order your pet's collar. A pronged collar should be snug and ride high on your dog's neck. Correction is given with a slower 'pull and release.'