Inbreeding in Cats? Specifically Siamese Cats?

I’m just wondering if anybody knows how common inbreeding in Siamese cats is? And what genetic defects can come from this inbreeding? Our old cat was a Siamese, and she had some very strange quirks, if you can call them that. I’m just curious to know how common inbreeding is and the genetic consequences it has on the cats. Thanks.

4 Answers

  1. There has been quite a lot of inbreeding in Siamese. There weren’t huge numbers imported from Siam in the first place. And many breeders intentionally inbred/ linebred to try to quickly get a certain appearance that would win in shows..This happened with colour, and it happened as the trend in Siamese body type went toward a more extreme look and people were trying to get there quickly by only breeding to cats at the most extreme end of the range of body type that was in the breed. In the process a lot of genetic material gets thrown out.

    Results? Fertility problems, smaller litter size, cancer, lowered immunity. thus susceptibility to certain diseases and thus reduced longevity, birth defects, miniaturization (with repeated inbreeding, animals will often get smaller.. and to make matters worse, judges have rewarded this miniaturization of the Siamese — I am not talking about the modern Siamese body type that is the current breed standard , I mean the actual size of the cat, not just its type. ),

    This is NOT to say that there are no healthy Siamese and no show breeders making an effort to find outcrosses and keep the inbreeding coefficient low.

    Here are some things about inbreeding written by a genetics professor and Siamese / Oriental breeder who is an advocate of avoiding inbreeding / linebreeding.

    I don’t know what quirks you are talking your cat, but you should be able to see from her pedigree if there was a lot of inbreeding in recent generations.

    If your cat was not a pedigreed Siamese , but just a random-bred domestic cat with the pointed pattern , then there’s no way to know how inbred she was. Many moggies are quite inbred. One dominant tomcat can sire most the kittens in a feral colony or in a neighborhood of free roaming cats, then goes on to breed with his daughters and grandaughters. The result is some random-bred cats have had a lot more inbreeding in recent generations than most breeders would use today.

  2. Its actually pretty common in siamese or siamese looking cats, they are a very popular breed and unfortunently there are alot of people who poorly and unresponsibly breed them, often alowing inbreeding or keeping them in conditions where inbreeding c an ocur. Several things can happen with inbreeding, it can cause physical disformites and nurological disorders or has simple as a compramised immune system. It can also cause such severe malformites that the cat either dies on its own or must be killed to end the suffering. Blindness, deafness, missing or malformed limbs, epilepsy, curved spines, kidney, heart and lung issues. Inbred cats also tend to be more aggressive. It really depends are how bad the inbreding is, as well as the condtions the cats live in, a mother-son pairing will generally have less effect then if the mother was also the sons grandmother, sister, aunt, ect. and if the father was also a grandfather, brother, uncle, ect.

  3. Siamese cats are well known for their good health if bred properly. Sadly there are people who inbreed them. inbreeding is used because breeders want to set traits and characteristics that they are looking for in their breed standard but however, there also risks in that such as health disorders. Weak immune system etc. in general birth defects. It’s horrible people do that to get what they want. Any responsible breeder would not inbreed their cats.

  4. they get crossed eyes

    poor immune systems, infertility, result from inbreeding

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