脱氧雪腐镰刀菌烯醇导致厌食和呕吐的机制研究进展

由镰刀菌产生的脱氧雪腐镰刀菌烯醇(DON)广泛存在于谷物及其加工产品中,对动物和人类健康有着潜在的危害。DON具有多方面的毒性作用,而厌食和呕吐是机体摄入DON后出现的最典型症状,厌食和呕吐的产生主要归因于DON对中枢神经系统和胃肠道食欲因子的影响。DON可直接作用于中枢神经系统的呕吐中枢产生呕吐反射,同时激活下丘脑神经元分泌食欲调节因子影响采食;DON可诱导肠内分泌细胞分泌肽YY、胆囊收缩素等食欲调节因子从而引发厌食;DON对中枢神经系统和胃肠道分泌的影响又可通过肠-脑轴产生关联;此外,细胞因子及肠道微生物也部分参与了反应的介导。本文综述了DON诱发机体出现厌食和呕吐的可能机制,以期为找到相应解决措施提供理论指导。     

Equine Coronavirus-Associated Colitis in Horses: A Retrospective Study

Equine coronavirus (ECoV) is a known cause of fever, anorexia, and lethargy in adult horses. Although there are multiple reports of ECoV outbreaks, less is known about the clinical presentation of individual horses during a nonoutbreak situation. The purpose of this study was to describe the clinical presentation of horses diagnosed with ECoV infection that were not associated with an outbreak. Medical records of all horses admitted to Washington State University, Veterinary Teaching Hospital, during an 8-year period were reviewed (2010–2018). The five horses included in this study were older than 1 year of age, were diagnosed with colitis, tested positive for ECoV using real-time polymerase chain reaction, and were negative to other enteric pathogens. Interestingly, 4 of 5 horses had moderate to severe diarrhea, 3 had abnormal large colon ultrasonography, 2 had transient ventricular tachycardia and 2 had clinicopathologic evidence of liver dysfunction. ECoV should be included as a differential diagnosis for individual horses presenting with anorexia, fever, lethargy, and colitis. Early identification of ECoV cases is key to implement appropriate biosecurity measures to prevent the potential spread of this disease.     

Osteomyelitis of the hyoid bones in two calves

Two calves were referred because of ptyalism and difficulty opening the mouth (Calf 1) and for elective umbilical hernia surgery under inhalation anaesthesia (Calf 2). Additional clinical signs were increased breath sounds and swelling in the region of the mandibular angle in Calf 1. Ultrasonography and endoscopy revealed oral inflammation and abscessation in the area of the base of the tongue in both calves. Infection of the hyoid apparatus was suspected based on ultrasonographic findings and confirmed by means of computed tomography. In Calf 1, there was no response to treatment with systemic antibiotics, nonsteroidal anti-inflammatory drugs and local lavage, and Calf 2 was not treated. Both calves were euthanized because of a poor prognosis and the diagnoses confirmed during postmortem examination. In Calf 1, the abscess was associated with complete destruction of the left epihyoid bone and partial destruction of the left stylohyoid and ceratohyoid bones. In Calf 2, the abscess was located at the distal end of the right stylohyoid bone near the epihyoid bone. Stomatitis or laryngeal and pharyngeal abscessation caused by sharp feed particles are common in cattle and infection of the hyoid apparatus should be included in the differential diagnosis.     

Metabolic and hormonal alterations in cats with hepatic lipidosis

Hepatic lipidosis in cats is a commonly diagnosed hepatobiliary disease of unknown cause. The purpose of this prospective study was to characterize the blood hormone and lipid status of cats with hepatic lipidosis, and to compare this status to that of cats with other types of liver disease and to control cats. Twenty-three cats with hepatic disease were assigned to 1 of 2 groups on the basis of cytopathologic or histopathologic examination of the liver: group 1, hepatic lipidosis (n = 18); or group 2, cholangiohepatitis (n = 5). Ten healthy young adult cats were used as controls. Food was withheld from control animals for 24 hours before blood collection. Concentrations of plasma glucagon and serum insulin, cortisol, thyroxine, triglycerides, cholesterol, phospholipids, and nonesterified fatty acids (NEFAs) were determined in all cats, in addition to routine hematologic and serum biochemical testing. Cats with hepatic lipidosis had higher serum NEFA concentrations than cats with cholangiohepatitis or control cats (P < .05). Cats with cholangiohepatitis had higher serum cholesterol and phospholipid concentrations than those of cats with lipidosis or control cats (P < .05); their plasma glucagon concentrations were higher than those of control cats (P < .05), but were not different from those of cats with hepatic lipidosis. Serum insulin concentrations were significantly higher in control cats than in diseased cats (P < .05), but neither serum insulin nor the insulin to glucagon ratio was significantly different among the cats with hepatic disease. The high concentration of NEFAs in cats with hepatic lipidosis suggests that at least 1 factor in the pathogenesis of this syndrome may involve the regulation of hormone-sensitive lipase.