| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Department of Pathology (FS, MP, MB, MH), Clinic for Small Domestic Animals (MF), and Department of Animal Breeding and Genetics (TL), School of Veterinary Medicine Hannover, Hannover, Germany
A clinical, morphologic, ultrastructural, and genetic study was performed on five rough-coated dachshund semisiblings with osteogenesis imperfecta (OI). Clinical signs consisted of pain, spontaneous bone and teeth fractures, joint hyperlaxity, and reduced bone density on radiography. Primary teeth were extremely thin-walled and brittle. The hallmark of the disease was a severe osteopenia characterized by impairment of lamellar bone formation in the long bones, skull, and vertebral column. No deformity or dwarfism was present. The columns of chondrocytes and primary trabeculae in the epiphyses and metaphyses were histologically normal. An abrupt failure of secondary spongiosa and lamellar bone formation was evident in the medullary and cortical zones in all animals. The few existing trabeculae consisted of woven bone. There was no increase in the number and size of osteoclasts or lacunae. In the teeth, the dentine layers were thin and lacked a tubular pattern. Ultrastructurally, osteoid apposition on bone surfaces was reduced, and small numbers of large cytoplasmic vacuoles were present in a few osteoblasts. Molecular analyses of the collagen type Iencoding genes COL1A1 and COL1A2 revealed several nucleotide differences compared with the published canine sequences but were not significant for OI. Therefore, OI in these Dachshund litters was characterized by a severe, generalized osteopenia and dentinopenia. This pattern of reduced bone formation is suggestive of defective production of collagen type I.
Key words: Bone; collagen; Dachshunds; histopathology; osteogenesis imperfecta; reverse transcriptionpolymerase chain reaction.
Request reprints from Dr. F. Seeliger, Institut für Pathologie der Tierärztlichen Hochschule Hannover, Bünteweg 17, 30559 Hannover (Germany). E-mail: frank.seeliger{at}tiho-hannover.de.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |