Chondrodysplasia (CDPA): A FGF4 retrogene insertion on chromosome 18 is linked to short-limbed phenotype in breeds such as Basset Hound, Pembroke Welsh Corgi, Dachshund, and Scottish Terrier.

Why This Matters to Breeders and Vets - Breeders: Genetic testing for the CFA12 FGF4 retrogene is strongly recommended for breeding programs, especially in high-risk breeds. Avoiding breeding dogs with the mutation can reduce disease incidence over time, but consider breed standards and diversity. Vets: Early recognition and genetic counseling are crucial. Clinicians must be alert for signs of IVDD in chondrodystrophic breeds and advise owners on risk, preventive care, and treatment options, including surgery and physical therapy. Population Health: The widespread presence of these mutations in many breeds means coordinated testing and breeding strategies are needed to reduce disease prevalence without excessively narrowing breed gene pools.