title: Age-related changes in the beagle spine.
abstract: Age-related changes were evaluated in the spines of beagle dogs by radiology, histology, and mechanical testing. Thirty healthy beagle dogs were divided into five groups having mean ages of 2-14 years. Radiographs were taken of intact spines at the time of death and of defleshed spines at necropsy. Cervical, thoracic, and lumbar segments were tested in compression to calculate peak stress, peak strain, and elastic modulus. Adjacent spine segments were graded grossly for osteophyte development, and sections of the intervertebral discs were evaluated histologically. Histologic evidence of disc degeneration and changes in the mechanical properties of the intervertebral disc joint preceded radiographic changes. Changes in the mechanical properties of the disc space were probably a result of the disc degeneration rather than the spondylitic lesions.
authors.affiliation: Inhalation Toxicology Research Institute, Albuquerque, New Mexico 87185.
authors.forename: N A
authors.initials: NA
authors.lastname: Gillett
authors.forename: R
authors.initials: R
authors.lastname: Gerlach
authors.forename: J J
authors.initials: JJ
authors.lastname: Cassidy
authors.forename: S A
authors.initials: SA
authors.lastname: Brown
mesh_terms: D000375:Aging / Q000473:pathology / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D004548:Elasticity; D005260:Female; D007403:Intervertebral Disc / Q000473:pathology / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D011859:Radiography; D013128:Spinal Osteophytosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology