Osteogenesis imperfecta also called pink tooth disease is a defect of bone mineralisation. It is inherited as a monogenic autosomal recessive trait in Dachshunds. Affected pups suffer from bone fractures after minimal trauma (e.g. during playing). Because of the fractures the affected pups are often in pain and try to avoid any movements. The teeth of affected animals have a pink or red color because the enamel is so thin that the underlying blood vessels can be seen. The teeth are also extremely fragile and frequently break off. Affected pups normally have to be put down because of the severity of the symptoms. We investigated the genetic mechanisms leading to osteogenesis imperfecta and identified the causative mutation in the SERPINH1 gene. This allowed the development of a DNA test that allows the unequivocal diagnosis of carriers for this disease..