Abstract
Background: Today, animals, like humans, suffer from spinal illnesses, which are aggravated in old age. Much emphasis is placed on diagnosis and treatment, but little focus is given to the spine's mechanical properties. Degenerative spine diseases are a major problem throughout the world. According to the World Health Organization, osteoporosis is a world-class public problem that reduces bone mass, resulting in bone fracturing and increased risk of bone fracturing. Therefore, the mechanical investigation of vertebrae can provide more information about the development of osteoporosis.
Case Description: For our case report, we used spayed mongrel lumbar vertebrae samples obtained from a canine which was about 8 years old and weighed 28 kg. The dog was diagnosed with a mammary tumour, and the dog’s owners decided to euthanise the dog. All consent forms were filled.
Conclusions: Mechanical tests were performed on three vertebrae, and a noticeable difference was observed in the first cycle of the first vertebra (L1). Second-order polynomials for displacement and seventh-order polynomials for pressure were proposed for describing the stress–strain relation of the vertebrae under the cyclical loads.
Our research protocol has been broken down into several parts. After measuring the area of the loaded surface, the largest area was in the L2 vertebra (176 mm ± 16; 177 mm ± 3 mm), and the smallest was in the L7 vertebra (156 mm ± 4 mm; 151 mm ± 33 mm). The smallest distance was recorded between the first (L1) and seventh (L7) lumbar vertebrae (L1) (15.17 mm ± 0.93 mm), and the largest distance was recorded between the L3 and L4 vertebrae of the lumbar (19.8 mm ± 3.7 mm).

Key words: canine; lumbar; vertebrae; osteoporosis; spine