Why test for SCID?

Severe combined immune deficiency (SCID) can appear in pure- and part-bred Arabians. Horses affected by SCID lack a functional immune system and are unable to fight infections. In their first few months foals are protected by antibodies in the mare's colostrum but as this protection declines their lack of immune system becomes apparent. The most common signs are respiratory illness, intermittent fever and/or diarrhoea. There is currently no effective treatment for SCID.

SCID is an autosomal recessive disorder. Autosomal disorders are equally likely to affect male or female horses, while "recessive" means that a horse needs to inherit the SCID mutation from both its sire and its dam to be affected. Horses that have inherited the SCID mutation from just one parent are called SCID carriers, and do not have physical signs of this disorder.

Any SCID carrier can potentially produce a foal suffering from SCID. Fortunately this is easily avoided: you simply need to ensure that the prospective foal cannot inherit the SCID mutation from both its sire and its dam. Therefore, if you have a SCID carrier horse and it is mated to a SCID-clear horse there is no risk of the foal being affected with SCID.

Some more information has been collected at WikiVet.

Discounted SCID testing

We provide discounted testing for the Arabian Horse Society of Australia: find their testing order form here. We support testing via the AHSA because:

• It allows the AHSA to keep a record of test results
• The prevalence and distribution of CA, SCID and LFS carriers can be monitored
• The AHSA is happy to test non-Arabian horses and ponies as well as full and part-bred Arabians

However, if you are in a hurry to find out your results the fastest option is to test directly with us.