Bit wider than that but you have the idea, you would not breed animals that had or were carrying health problems to anything, line breeding or out breeding, well I hope you would not

Line breeding or In breeding will double up on anything carried in the genes, the clever breeder makes sure the as far as possible only the required elements are carried forward in their lines. The very fact of Line Breeding does not cause health problems, they have to be there in the first place.

is line breeding practiced alot in dog breeds? i dont have much idea about other breeds but there is only 2/3 breeders in the world who have line bred APBT's even then none can say that those dogs have not been out crossed is it something breeders with other dogs do? is there anyline breeders here?

when line breeding its always worth looking to make sure no bad faults are doubled up on ..esp in cavaliers as we have syringomyelia to think about ....I would look for a link between the 2 pedigree's ....but i have to say the best litter i ever bred was an outcross ( thats my india )
we repeated that mating 18 months later and had just as good

Not sure what you are asking but yes all breeders will line breed it is the only way to 'fix' your breed type or a particular feature that is thought to be excellent. Think most breeders will out breed on occasion but it is when you out breed that the problems are likely to occur because however careful you are to research the background of the animal you wish to use it is always possible that there may be something lurking under the surface. Line breeding does not necessarily mean breeding close just breeding to animals that carry your own lines genes. Breeding practices is a complicated business and every breeder will have there own ideas about how close they should breed and why, and of course how often they should bring in new blood and why. There is always the stud who does not pass on the required features and the not so good one who produces excellent pups, good breeder get a feel for what will be passed on and what will not.

There are textbooks available that explain which gene for which traits are dominant and which are recessive but in theory most breeders start their breeding career under the guidance of an experienced breeder and only use the text books when something is not going as expected.

Inca, you were posting whilst I was writing and my comments were in no way directed at your comments about out breeding/crossing. was replying to the post above yours.

no probs hun ...... although we researched the pedigree it can be risky not just in looks but health as well ....we were happy with the health side of things AND WERE VERY LUCKY that the offspring were superb

but i do realise this isn't always the case ..did it many years ago with disapointing quality

This has been an excellent thread, very interesting!