This is a very controversal subject and I have chosen to be anon for that reason. Also I believe that it is better said without my opinion since this is an observation. There are 4 types of breeders of domestic ferrets. Though there are variations in each category, I thought it prudent to point out their differences . 1. Line-Breed Breeder - the line is re-introduced at some point prior to five generations. Most often times these breeders breed to get one specific color or body shape. Most often times these breeders prefer the "bottle -type rib cages". This means that the rib cage doesn't not protrude and is usually flat or fused so there's no definition. These type breeders who breed for color will often use one color and repeatedly introduce the line from 3-5 generations back into itself. Other wise called by some as "Selective Line Breeding". 2. In-Breed Breeder - the line is re-introduced at 1-3 generations. Many of these breeders breed for the same objectives as the line-breed breeder does but these breeders are more specifically after color rather than body shape. 3. Color Breeding - this means the breeder is only looking for color and therefore doesn't practice just one type of breeding but may introduce 2 methods to produce a particular color. Most often times, no pedigrees are kept for this type of breeding since the lines themselves are not the main goal but rathe r the ending color. 4. Clean Breeding - this means there is no color, line -breeding or inbreeding methods used. These breeders breed no closer than 5 generations and breed for specifically health and longevity. Color is usually the end result but not necessarily the goal. These breeders most often times will breed for "sprung rib cages". This means the rib cage is defined. Of course each one has a slight variation depending upon the breeder, some use numerous methods to get the end result they want. One of the main differences in a "clean bred" ferret as opposed to a specifically "inbreed" or "line-breed" ferret is usually the rib cage and/or skeletral structure and body type. Some continuous line or inbreeding has caused the line to introduce the whippet or standard body type more continously instead of that of the bulldog type. Also the "base stock" or "foundation breeders" help to determine the structure as well. Some breeders prefer not to use any foreign lines whereas so me do. There are so many methods of breeding. I personally believe that manipulating the line is unhealthly and prefer to only use the "clean breeding" method. But others have their opinions. I just wanted to point out to those who where not familiar with the methods of breeding that there are 4 types of breeders (some use more than one method but they usually use one more consistently). I am not a vet or specialists but have a degree in biology and before 5 generations there is a chance of mutation of the genes which could cause several birth defects in the offspring or their children. But it is up to you all to decide what method if you breed you use and/or if purchasing what type of breeder you want to deal with. These breeders base their breedings for the following year on "suppy and demand". My opinion is also that in order to educa te the public that ferrets are not rodents you have to treat every aspect of the ferret as a ferret and not a rodent. Rodents inbreed and linebreed, why do it t o a ferret, it only unravels the precedent ferrets are not rodents. Again my opinion, other breeders may have reasoning for doing the line or inbreeding but I think to the DOG SHOWS, where the german shepherds where so linebreed and inbreed to produce lower backs that they most often times suffer from hip problems. I cannot imagine a ferret have such a result. [DP] [Posted in FML issue 4678]