The goal of cat breeders should be to found (establish) a line of healthy cats which excel in reference to the breed standard of the cat association at which their cats are registered.
The word “line” in cat breeding comes from the word “bloodline”. Bloodline means an animal’s line of ancestors with particular reference to their desirable characteristics which are selectively bred into the animal. This is a pedigree. The pedigree is a list of the great-grandparents (and earlier) through to current offspring. It is a “line” of cats from one generation to the next.
In cat breeding, as I understand it, the cat fancy obliges cat breeders to register a cattery name and then register all the kittens that are born to previously registered parents under that category name. A certain amount of inbreeding takes place within this line due to selective breeding which enhances the desirable characteristics with particular reference to the appearance of that line of cats. In other words, the word “line” describes “a group of closely related cats that have been inbred for several generations, that is beyond five or six generations”. Sometimes the word “strain” is used instead of “line”.
The authors of the book “Robinson’s Genetics for Cat Breeders and Veterinarians” argue that the word should be restricted to describing a “stock of cats of distinctive, if not truly exceptional merit”. Further, it should be used to describe a cattery of “relatively true breeding cats that possess unique features that tend to make them stand out as a group”.
This takes years of selective breeding and success in competition at cat shows. I am thankful to the authors of the book referred to above for the information provided in this post.
Comment: I feel obliged to take this opportunity to mention a pet concern of mine (excuse the pun) namely the need to prioritise or at least emphasise the health of cats bred at catteries. Sometimes health is a secondary consideration after appearance. This is because appearance is emphasised in breed standards and is vital for success at cat show competitions. However, the health of a cat should be an inviolable standard and should not in any way be undermined by selective breeding for appearance. In other words the priority is health, while appearance comes second. This is not, regrettably, what happens some of the time in the cat fancy. Perhaps this is because of a blinkered desire to create outstanding cats while the consequences are conveniently brushed under the carpet.
It is disappointing to report that on occasions the cat associations encourage breeders to overlook health aspects. The classic example is the flat-faced Persian cat’s breathing difficulties and a propensity towards acquiring the condition polycystic kidney disease (PKD). This is somewhat of a scandal within the Persian cat breeding community
In an article I wrote many years ago, I said that an estimated 37% of Persians suffered from PKD1. And that the breed accounts for nearly 80% of the cat fancy. Those figures may well be outdated today but they do give an indication as to the gravity of the problem in failing to prioritise health over appearance. It is said that in general 50% of PKD1 positive cats’ offspring inherit PKD1. The Persian is a classic example of this breeding problem. It is not the only one.
Some more on Persian cat breeding