[bay_blnd jmpr07]

what exactly is this? waht does it do to the horse? all i know is its something that Arabians get

BBJ

[arabkid]

I can't explain to you exactly what it is, but I can tell you that it's impossible that the foals have it unless one of the parents have it. So as long and you breed her to something that is scid clear your foal won't get it...

we have had horses that have had it, because Versace is a scid carier and we have bred to him wuite a few times.

http://www.vetgen.com/scidbre.html <- there is a link to what it is!

[bay_blnd jmpr07]

Versace is cute...lol sorry, i remember his pic LOL

BBJ

[Sandra-A1]

SCID in Arabian Horses

SCID is rather a deficiency of the immune system which predisposes the new-born foal to infection.
Offspring inherit one copy of all genes from their mother and another complete copy from their father. With a recessive mutation, one gene copy in the individual may be defective, but providing the second copy inherited from the other parent is normal, it will function and the animal will appear perfectly normal. In SCID this means that foals which inherit only one copy of the defective gene (inherited from either their dam or sire) do not show any symptoms of the disease, but do carry it and can pass it on to their offspring.
This is where the problem arises; 'carriers' appear perfectly normal and cannot be identified by appearance. Until now carrier horses could only be identified in the breeding population once they produced affected offspring - affected foals can result only from breeding two carriers, so an affected foal proves that both of its parents are carriers. However, if a carrier is never bred with another carrier (or if affected offspring have not been identified as SCID victims), it would not be identified as a carrier, although 50% of the offspring will themselves be carriers. In this way the disease is propagated. It is worth noting that only one quarter of offspring resulting from the breeding of two carriers will be affected foals and none of the offspring from a normal-carrier mating will be affected. A string of healthy offspring cannot therefore prove that an animal is not a carrier. Finally, the disease is not sex-linked, i.e. males and females are equally likely to be affected.

SCID was first reported in Arabian foals in 1973 by McGuire and Poppie, Australia. In 1980, Perryman and Torbeck, in the U.S. , showed that SCID in Arabian horses was inherited as an autosomal recessive condition, which means that one copy of the disease gene is inherited from a carrier stallion and another from a carrier mare. The foal which inherits two copies of the disease gene is affected with a lethal inability to fight infections, and dies within the first few months of life.

Matings between two clear horses as well as matings between a clear and a carrier horse will NEVER produce an affected animal. By definition, carriers of genes for autosomal recessive disorders are completely free of clinical signs of the disease. That is, carriers do not have any negative consequences to their health or performance. If two carriers are mated, there is a 25% chance that the foal will be clear, 50% chance that it will be a carrier and 25% chance that it will be affected, a chance not worth taking.

Prior to the advent of molecular genetic testing for autosomal recessive disorders, the only way an Arabian Horse was identified as carrier was when he or she produced an affected offspring. The traditional recommendation in veterinary medicine would be gelding of these animals to prevent other affected offspring being produced. This is no longer necessary and not in the best interest of the breed. Carrier horses that have desirable traits can now be mated to tested horses that are clear and never produce an affected foal. Their offspring can be tested and appropriate matings set up in the next generations without the breed suffering the loss of another foal to SCID. The breed continues to benefit from all of the outstanding traits a carrier animal may possess. The economic value of the Arabian Horse should not be affected by being clear or carrier.

[arabkid]

Originally Posted by bay_blnd jmpr07

Versace is cute...lol sorry, i remember his pic LOL

BBJ

lol we have had lots of his foals....haha

[bay_blnd jmpr07]

Thank you Sandra

BBJ