Skeletal dysplasia 2 (SD2)
Skeletal dysplasia 2 is an inherited musculoskeletal disease affecting Labrador Retrievers. Affected dogs develop a mild form of “disproportionate dwarfism” consisting of short legs with normal body length and width. The leg bones are shorter, thicker, and slightly curved and the front legs are frequently more affected than rear legs. Joints and eyes are not typically affected with this disease. The height of affected dogs is variable, making diagnosis based on physical characteristics alone challenging in some individuals. Mildly affected dogs from bloodlines known to produce large dogs may still fall within their breed standard for height. The causal mutation shows incomplete penetrance meaning that not all dogs inheriting two copies (one from each parent) will display obvious physical characteristics of dwarfism.
- Frischknecht M, Niehof-Oellers H, Jagannathan V, Owczarek-Lipska M, Drogemuller C, Dietschi E, Dolf G, Tellhelm B, Lang J, Tiira K, Lohi H, Leeb T. A COL11A2 mutation in Labrador Retrievers with mild disproportionate dwarfism. PLoS One. 2013;8(3):e60149 [PubMed: 23527306]