In the wake of recent misrepresented SCID data there is a need for some factual information.

In Arabian Visions October 1998 issue page 8 there is the following information:

"SCID is an inherited, autosomal recessive disease affecting Arabian and part-Arabian foals. Foals with two copies of the gene lack functional immune systems and succumb to infectious disease prior to six months of age. Horses with one copy of the gene are unaffected and live normal, healthy lives, but can have affected foals. The SCID gene test, developed in 1997, identifies those horses with one copy of the gene so that breeders can avoid mating two such horses. With this knowledge, no SCID foal need be produced again." (Note: SCID is NOT contagious!)

Additionally, there is an excellent & very complete article in Equus, Volume 239 - September 1997 page 43 called "Closing In On A Killer Gene". This article documents the search for the gene, describes how the disease works, diagrams the genetics that produce a clean offspring, a carrier, and the fatal recessive that causes death.

Finally, visit www.foal.org for a listing of horses that have been tested and posted their results with the F.O.A. L. organization. Unfortunately, F.O.A. L. only accepts results from one lab so anyone (like me!) who tested elsewhere cannot share their results through them. A complete list of tested Destiny Arabians horses can be seen here. Also check out the SCID INFO link for another good source of SCID information.

Now, my opinion:

Responsible breeders now have the tools to identify SCID carriers and to make breeding decisions that can still utilize the bloodlines of the SCID carrier without producing an SCID foal. We also have the tools to completely eliminate the rumor and innuendo tactics used to discredit stallions, as employed in the 1970's & 1980's when the SCID scare was rampant. By testing your breeding stallions you can make knowledgeable recommendations about your stallions to mare owners. By being aware of potentially affected bloodlines you can offer a service to your clients when you recommend a test of their mare to avoid a possibly hazardous mating. Shouldn’t this be part of our responsibility as informed breeders? Already ad campaigns are being seen with Tested SCID Negative prominently displayed. I believe the stigma is being lifted with the ability to test.

AA = Clean Horse - No SCID Gene and cannot pass it on

Aa = A Carrier - Carries and can pass on the SCID Gene

aa = A victim of SCID with 2 copies of the SCID Gene.
This horse will die prior to 6 months of age because
it has no immune system to fight off infection.

The following charts reflect the gene makeup in resulting offspring when breeding Clean and Carrier horses together using the theories of Mendelian Genetics.

Clean (AA) to Clean (AA) results in 4 SCID clear offspring.

Clean (AA) to Carrier (Aa) will result in 50% Clean and 50% Carrier offspring.

Breeding Carrier (Aa) to Carrier (Aa) will result in 25% Clean (AA) offspring, 50% Carrier (Aa) offspring and the tragedy of the affected foal (aa) - 25% - that will not live to  be 6 months of age.

I am pleased to report that all of the horses tested for Destiny Arabians tested Clear. Our testing was conducted through Gene Check prior to the VetGen lawsuit where VetGen gained a monopoly on the test process.

Bob & Sheila Harmon
P.O. Box 1180 - Eagle, Idaho 83616
(208) 322-8474 - (208) 866-1024
800-327-6540
E-Mail to: Sheila@DestinyArabians.com
Web Page: www.destinyarabians.com