A Comparison of Two-Dimensional and Three-Dimensional Techniques for Kinematic Analysis of the Sagittal Motion of Sheep Hindlimbs During Walking on a Treadmill.

Compared to rodents, sheep offer several attractive features as an experimental model for testing different medical and surgical interventions related to pathological gait caused by neurological diseases and injuries. To use sheep for development of novel treatment strategies in the field of neuroscience, it is key to establish the relevant kinematic features of locomotion in this species. To use sheep for development of novel treatment strategies in the field of neuroscience, it is crucial to understand fundamental baseline characteristics of locomotion in this species. Despite their relevance for medical research, little is known about the locomotion in the ovine model, and next to nothing about the three-dimensional (3D) kinematics of the hindlimb. This study is the first to perform and compare two-dimensional (2D) and 3D hindlimb kinematics of the sagittal motion during treadmill walking in the ovine model. Our results show that the most significant differences took place throughout the swing phase of the gait cycle were for the distal joints, ankle and metatarsophalangeal joint, whereas the hip and knee joints were much less affected. The results provide evidence of the inadequacy of a 2D approach to the computation of joint kinematics in clinically normal sheep during treadmill walking when the interest is centered on the hoof's joints. The findings from the present investigation are likely to be useful for an accurate, quantitative and objective assessment of functionally altered gait and its underlying neuronal mechanisms and biomechanical consequences.

The use of sheep as a model for studying peripheral nerve regeneration following nerve injury: review of the literature.

Peripheral nerve injury and regeneration is a challenging scientific field with relevant clinical implications. Most peripheral nerve regeneration studies have been mainly carried out on rodents. However, it is important to note that the validity of the rodent as a model to study nerve injury and regeneration and translate these results into clinical practice has been questioned by several researchers. To overcome this problem, some investigators have used companion animals and large animal species as models for experimental peripheral nerve regeneration studies. Live sheep are often used in biomedical research because of availability, simplicity of care and housing, cost and body weight similar to humans and acceptance by society as a research animal. Despite these advantages, studies on nerve regeneration and repair in sheep have only been undertaken a few decades ago and compared to rat and mice experimental studies, there are much fewer investigations. The authors have compiled and sorted the available literature on experimental ovine nerve studies in order to guide the peripheral nerve investigator in choosing clinically relevant and interpretable models for studies on neural regeneration that are much needed in order to make progress towards new surgical and medical treatment of peripheral nerves.

Diagnosis and Treatment of Primary Erythrocytosis in a Dog: A Case Report.

Primary erythrocytosis, or polycythemia vera, is a myeloproliferative disease caused by the exaggerated increase of erythroid precursor cells in the bone marrow. We report the case of an 11-year-old male mixed-breed dog that had tachypnea and spastic tetraplegia. There was a significant increase in hematocrit. After phlebotomy and fluid therapy, the dog's condition improved. A diagnosis of primary erythrocytosis was supported by serum levels of erythropoietin. The dog responded well to treatment with administration of hydroxyurea (15 mg/kg), phlebotomies, and fluid therapy. However, after 18 months, he had an acute recurrence of clinical signs and was euthanized. We observed that long-term maintenance with hydroxyurea at a dosage of 15 mg/kg every 48 hours was adequate for managing polycythemia vera, with a survival time of 18 months in the present case. However, longer dose intervals are likely not appropriate. We believe that this may be helpful to other veterinarians facing the same problems in the treatment of polycythemia vera.