Effects of oral treatment with chondroitin sulfate and glucosamine in an experimental model of metacarpophalangeal osteoarthritis in horses.

BACKGROUND: Combined chondroitin sulfate (CS) and glucosamine (GlcN) has been widely used in oral formulations to prevent and treat osteoarthritis. CS is effective for controlling pain in osteoarthritic patients, whereas GlcN can stimulate glycosaminoglycan synthesis, thus reducing extracellular matrix degradation. Although several studies have been published on this topic, the effectiveness of treatment with oral CS and GlcN remains uncertain. The objective of this study was to analyze the progression of experimentally induced osteoarthritis in horses and verify the effectiveness of an oral compound based on CS and GlcN to treat and/or modulate this disease. The study analyzed the metacarpophalangeal joint of the left thoracic limb of 16 horses divided into two groups, with eight horses treated with CS and GlcN in the treated group (GT) and eight untreated horses in the control group (GC). Chondral lesions were induced through arthroscopy, which was defined as time-point zero (T0). Physical, ultrasonographic, and radiographic examinations and synovial fluid biomarkers measurements were performed on days 0, 30, 60, 90, and 120. At the end of the experiment (T4), arthroscopy was performed again to macroscopically evaluate the joints and collect material for microscopic analysis. RESULTS: Significant differences were observed between groups in some evaluated parameters, such as visual lameness assessment, synovial concentrations of prostaglandin E2, and ultrasound examination. However, the GT still presented slightly improved results for joint flexion angle, analysis of lameness using sensors, and histopathological analysis of chondral repair tissue, however, without the statistical significance (p>0.05). CONCLUSIONS: The treatment was considered effective in the clinical modulation of experimental osteoarthritis, with improvement of some parameters in the GT. However, this type of treatment may not be entirely effective to change the catabolic process in articular cartilage and the progressive induced chondral damage.

Morphological analysis of third metacarpus cartilage and subchondral bone in Thoroughbred racehorses: An ex vivo study.

Racehorses are exposed to repetitive overload during training and competition, causing joint hyperextension, tissue fatigue, and ultimately skeletal failure. Some degree of bone changes, such as sclerosis, are expected in equine athletes, as adaptation to the biomechanical rigors of training and racing. Understanding the imaging characteristics of the equine joint surface and subchondral bone would allow earlier detection of injuries or adaptation, improving prognosis and training programs. This study sought to describe the joint surface structural patterns and the periarticular structures of the third metacarpal bone (MC3). Both forelimbs of eight horses engaged in daily training programs, aged 3-5 years, which were euthanized for reasons unrelated to the metacarpophalangeal (MCP) joints, were collected. Specimens were evaluated through macroscopic inspection, radiography, ultrasonography, and microscopic examinations, such as optical microscopy and microtomography. Analysis of the microtomography images showed that 50% of the samples had higher trabecular thickness in the lateral condyle. Comparison of each imaging examination revealed that ultrasound images were most closely related to the histological examination (p = .29) in terms of sensitivity, while macroscopic and radiographic examinations differed most between evaluators. Finally, the irregularities and modifications observed in the articular cartilage surface and subchondral bone were normal adaptations of the anatomical structures of trained racehorses, which should be considered during clinical examination.

Glossopharyngeal and vagus neuropathy associated to stylopharyngeus muscle compression in horse guttural pouch ­ case report / Neuropatia do glossofaringeo e vago associada à compressão pelo musculo estilofaringeo em bolsa gutural de equino ­ relato de caso

Neuropathies of pharyngeal branches of glossopharyngeal and vagus are often associated with guttural pouches diseases; however, these branches of injury due to stylopharyngeus muscle compression are not reported. A case was reported of a quarter horse mare, 8 years old, 450 kg, presenting dyspnea and respiratory noise associated with weight loss. Clinical examination observed mixed dyspnea, tachycardia, dysphagia, sialorrhea, lung crackles and submandibular and parotid lymphadenopathy. Endoscopic exam showed right arytenoid chondritis, nasopharyngeal collapse, generalized larynx edema and dorsal displacement of the soft palate. Right guttural pouch evaluation showed swelling in the origin of stylopharyngeus muscle with consequent compression of the XII, X and IX cranial nerves. Tracheotomy, systemic treatment with corticosteroids, beta lactams and aminoglycosides antibiotics were performed. No resolution was observed and, after 16 days, the animal showed clinical worsening, developed pleuropneumonia, uveitis, severe sepsis, acute renal failure and was euthanized. The mixed neuropathy resulted in rapid clinical deterioration of the animal, due to the difficulty in swallowing and consequent associated respiratory processes. This report emphasizes the importance of evaluating stylopharyngeus muscle origin in cases of nasopharyngeal collapse associated with dysphagia in horses, given the possibility that structural changes in this muscle can result in laryngeal neuropathy.(AU)

As neuropatias do glossofaríngeo e vago são frequentemente associadas com enfermidade das bolsas guturais. A ocorrência desta lesão secundária a compressão pelo músculo estilofaríngeo não é reportada. Relata-se o caso de uma égua quarto de milha, 8 anos de idade, 450 kg, apresentando dispneia, ruído respiratório e perda de peso. No exame clínico observou-se dispnéia mista, taquicardia, disfagia, sialorréia, crepitação pulmonar e linfadenopatia submandibular e parotídea. Ao exame endoscópico identificou-se condrite aritenóide direita, colapso nasofaríngeo, edema generalizado da laringe e deslocamento dorsal do palato mole. Na avaliação da bolsa gutural direita identificou-se aumento de volume na origem do músculo estilofaríngeo com consequente compressão dos nervos cranianos XII, X e IX. Foi realizada traqueotomia, tratamento sistêmico com corticosteróides e antibióticos. Nenhuma resolução foi observada, após 16 dias o animal apresentou piora clínica, pleuropneumonia, uveíte, sepse grave, insuficiência renal aguda e foi submetido à eutanásia. A neuropatia mista resultou em rápida deterioração clínica do animal, devido à dificuldade de deglutição e processos respiratórios associados. Salienta-se a importância de se avaliar a origem do músculo estilofaríngeo em casos de colapso nasofaríngeo associado a disfagia em cavalos, dada a possibilidade de que alterações estruturais nesse músculo possam resultar em neuropatia laríngea.(AU)