The phrase "medium breed" refers to a type of animal, usually dogs, that falls in between small and large in terms of size. These animals are not too small or too big, but average in size. Full definition
Small to medium breed puppies usually have all their adult teeth by the end of their sixth month, for larger breeds it can take a couple of months longer. (raisingrascal.com)
This chicken and brown rice formula is especially prepared for medium breed dogs from age 1 year of age. (dogfoodselector.com)
Size 2 is for medium breeds of dogs from 6 kg up to 20 kg. (dogsbarn.com)