Testing for Spider Lamb Syndrome

    A spider lamb is usually evident when it is born, but a normal lamb can show signs within 6 weeks of being born.  The best way to utilize testing is to genetically test the production flock in order to eliminate the possibility of producing a spider lamb.  The genetic mutation can be identified by testing the DNA that is isolated from blood or semen. 

    The use of test crosses has greatly benefited the entire sheep industry by allowing producers to determine if any individuals in their flock have the probability of producing a spider lamb.  In most cases, a known NS is crossed with an unknown genotype.  If the result is the birth of a spider lamb, the producer then knows that the other parent is also a carrier.  In most cases, excluding research, these carrier parents are slaughtered to remain out of the breeding flock.

References

Identification of Sheep Genetically Free of Spider Lamb Syndrome

Spider Lamb Syndrome - 1998 Sheep Day Report