Megacolon

"A change in breeders' attitude and breeding practices is mandatory because neither the permanent elimination of animals not "fitting" a fancy standard nor the continuous production of defective genotypes is legal." - Gerlitz S, Wessel G, Wieberneit D, Wegner W.

Megacolon is a genetic condition that is caused by the KIT gene. This comes into play when a rabbit inherits two of the dominant versions of the "English spotting gene" (En/En). There are three options possible when inheriting the spotting genes. The latest genetic study, from the University of Bologna in Italy, shows that if a rabbit inherits a recessive and dominant (En/en) or two recessive (en/en) English spotting genes they will not have megacolon. Only rabbits that inherit two of the dominant versions of the "English spotting gene" can be affected by megacolon.

During early cell migration early in the rabbit's embryonic development the KIT gene expresses itself causing megacolon. It controls processes such as cell division and movement. It also plays a part in the development of cells in the GI tract and cells called melanocytes (melanin). There is a large reduction of cells in the rabbit's GI tract (cecum and ascending colon) in the outer muscle wall.