Evaluation of brain damage resulting from penetrating and non-penetrating captive bolt stunning using lambs

OBJECTIVE: To compare the brain damage in sheep resulting from penetrating and non-penetrating captive bolt stunning. DESIGN: The unrestrained heads of anaesthetised lambs were impacted in the temporal region with penetrating and non-penetrating captive bolt pistols (humane stunners) using a constant charge. Two hours after head impact, brains were perfusion-fixed with 4% paraformaldehyde. Coronal sections were stained with haematoxylin and eosin and immunohistochemically for amyloid precursor protein, a sensitive marker of axonal and neuronal reaction in brains after trauma. Pathological changes in these brains were then quantified by morphometric analysis. RESULTS: The skull was fractured in 50% of lambs after a non-penetrating head impact and in all animals after a penetrating head wound. Impact contusions were present in 80% of lambs receiving a non-penetrating head injury and in all of those with a penetrating wound. Total contusion area was similar in both groups. Amyloid precursor protein-positive axons and neurons, and haemorrhage, were widely distributed in the brain after both head impact types, but there was no statistically significant difference between the two groups. Multifocal necrosis of the cerebellar granular layer was found in all lambs with non-penetrating head injury, but in none with a penetrating injury. CONCLUSIONS: The structural brain damage, a mixture of focal and diffuse injury, produced by penetrating and non-penetrating captive bolt pistols was overall similar and of sufficient severity to suggest that both types of weapon are acceptable for euthanasia.     

Brain damage in pigs produced by impact with a non-penetrating captive bolt pistol

OBJECTIVE: To assess the effect of impact with a nonpenetrating captive bolt pistol in pigs by studying the resulting traumatic brain injury (TBI) and to compare the pathological changes with those found previously in the brains of sheep using a similar experimental paradigm. PROCEDURE: The unrestrained heads of six, anaesthetised, 7- to 8-week-old, Large White pigs were impacted in the temporal region with a nonpenetrating captive bolt pistol. Four hours postimpact, brains were perfusion-fixed with 4% paraformaldehyde. Coronal sections from six levels along the brain were cut and stained with haematoxylin and eosin and immunohistochemically for amyloid precursor protein, a sensitive marker of axonal injury (AI) in the brain after trauma. RESULTS: TBI in pigs was characterised only by very mild AI, whereas AI in sheep after captive bolt impact to the same head region was much more severe and widely distributed and often associated with vascular damage such as contusions, subarachnoid and intraparenchymal haemorrhage. CONCLUSIONS: TBI in pigs was much less severe than in sheep after non-penetrating mechanical impact of similar magnitude, confirming the importance of interspecies differences in determining an appropriate physical method of euthanasia.     

金属硫蛋白对海马CA1区锥体细胞凋亡的抑制作用

采用股动脉放血并双侧颈总动脉夹闭制作全脑缺血再灌注模型 ,于术后 1d处死动物 ,取脑 ,制作石腊切片 ,通过 HE染色、Tunel检测 ,对海马 CA1 区锥体细胞形态进行了观察。结果表明 :在短暂性全脑缺血中 ,海马锥体细胞存在着凋亡和坏死 2种死亡形式 ;与对照组相比 ,缺血再灌注后 1d,海马 CA1 区损伤较重 ,出现了较多的凋亡细胞 ,而MT- 1可明显抑制锥体细胞的凋亡。本试验证明 :在脑缺血再灌注损伤中 ,细胞凋亡是神经元死亡的一种重要形式 ;MT- 1对脑缺血再灌注有明显神经保护作用     

Brain injury after head trauma: pathophysiology, diagnosis, and treatment.

Brain injury after impact to the head is due to both immediate mechanical effects and delayed responses of neural tissues. In horses, traumatic brain injury occurs in three main settings: (1) poll impact in horses that flip over backwards; (2) frontal/parietal impact in horses that run into a fixed object, and (3) injury to the vestibular apparatus secondary to temporohyoid osteoarthropathy.Distinct forebrain, vestibular, midbrain, hindbrain, or multifocal syndromes may be encountered in horses with traumatic brain injury. The most important components of treatment are those consistent with principles of "evidence-based medicine". Accordingly,secondary brain injury can most effectively be prevented by establishing normal blood pressure, temperature, blood glucose concentration, and tissue oxygenation. Pain must be controlled and brain swelling may be treated with infusions of hypertonic saline or mannitol. Surgical procedures, including unilateral hyoid bone transaction or elevation of skull fracture fragments, are indicated in selected cases. Optional additional treatments include use of anti-oxidants, conventional doses of corticosteroids, magnesium sulfate and drainage of CSE There is no indication for the use of massive doses of methyl prednisolone sodium succinate.     

中草药复合微生态制剂对急性肝脏损伤蛋鸡肝脏保护作用的研究

试验旨在研究中草药复合微生态制剂（CHCP）对急性肝脏损伤蛋鸡肝脏的保护作用。试验分两部分：①用四氯化碳豆油（SCCl₄）建立蛋鸡急性肝脏损伤模型。选取1 d健康蛋雏鸡108只随机分为4组,模型Ⅰ~Ⅲ组分别按1、2、4 mL/kg体重灌胃10%（V/V）SCCl₄,对照组按2 mL/kg体重灌胃豆油,分别在14、28及35 d时各灌胃一次;②CHCP对蛋鸡急性肝脏损伤的影响。选择1 d 健康蛋雏鸡60只随机分为5组：对照组（豆油）、模型对照组（SCCl₄）及低、中、高剂量CHCP组（SCCl₄+1‰ CHCP、SCCl₄+2‰ CHCP、SCCl₄+4‰ CHCP）,7 d起饮水使用CHCP,14、28 d按2 mL/kg体重剂量给鸡灌胃10% SCCl₄。结果表明,按2 mL/kg体重剂量在14、28 d分别灌胃10% SCCl₄即可造成蛋鸡肝脏损伤,引起肝细胞脂肪变性,空泡样变严重,核固缩,坏死;与模型对照组相比,低、中、高剂量CHCP组蛋鸡血清谷草转氨酶（AST）含量分别降低4.35%（P > 0.05）、7.57%（P > 0.05）及9.79%（P < 0.05）,中、高剂量CHCP组血清谷丙转氨酶（ALT）含量分别降低34.92%（P < 0.01）、36.51%（P < 0.01）,血清总胆红素（TB）含量分别降低25.49%（P < 0.01）、27.45%（P < 0.01）;蛋鸡肝细胞切片显示CHCP不同剂量组肝细胞充血减轻,未见脂滴空泡,排列整齐,细胞质丰富而均匀。结果表明,本试验所用的CHCP按2‰、4‰饮水使用均能减少肉鸡肝细胞坏死,降低血清转氨酶活性及TB水平,对SCCl₄诱导的肝脏损伤有保护作用。     

Use of external coaptation for the treatment of avascular necrosis of the femoral head in a dog

Avascular necrosis of the femoral head was diagnosed in a 5-month-old Schipperke, before the development of femoral head and neck collapse and resultant degenerative joint disease. External coaptation, consisting of an Ehmer sling, was used to prevent the bearing of weight during revascularization and reossification of the subchondral bone. Results of pelvic radiography (at 10 and 24 weeks) indicated that the early use of conservative treatment was successful in promoting resolution of the aseptic necrosis and in maintaining normal coxofemoral anatomic features and function.     

Study on Liver-protective Effect of Chinese Herbal Compound Probiotics on Acute Liver Injury Layers

This experiment was conducted to investigate the liver-protective effect of Chinese herbal compound probiotics (CHCP) on acute liver injury layers.One hundred and eight 1 day old hens were divided into 4 groups with 3 replicates in each group and 9 layers per replicate in trial 1.The layers in model groups Ⅰ to Ⅲ were gavaged with 10% (V/V) soybean oil solution of carbon tetrachloride (SCCl₄) according to 1,2 and 4 mL/(kg·BW) at 14,28 and 35 d,respectively.The layers in control group were gavaged with 2 mL/(kg·BW) soybean oil.In trial 2,sixty 1 d layers were divided into 5 groups:Control group (soybean oil),model control group(SCCl₄)and low-dose,middle-dose and high-dose CHCP group (SCCl₄+1‰ CHCP,SCCl₄+2‰ CHCP and SCCl₄+4‰ CHCP respectively).CHCP were used by drinking water since 7 days.SCCl₄ were gavaged according to 2 mL/(kg·BW) at 14 and 28 d.The results showed as follows:The model of layers liver damage could be built by intragastric administration of 2 mL/(kg·BW) 10%(V/V) SCCl₄ at 14,28 d respectively,with the signs of hepatic steatosis,severe vacuolar degeneration,nuclear condensation and necrosis.Compared to the model control group,the serum AST levels in low,medium and high dose CHCP groups were decreased by 4.35% (P > 0.05),7.57% (P > 0.05) and 9.79% (P < 0.05),the serum ALT levels in medium and high dose CHCP groups were decreased by 34.92% (P < 0.01),36.51% (P < 0.01),the serum total bilirubin content in medium and high dose CHCP groups were decreased by 25.49% (P < 0.01),27.45% (P < 0.01).The liver cell congestion was reduced to varying degrees in different dose CHCP groups,and the liver cell had no vacuoles,arranged in neat rows,abundant cytoplasm and uniform in different dose CHCP groups.In conclusion,2‰,4‰ CHCP could reduce hepatocyte necrosis,decrease the serum activities of ALT,AST and total bilirubin levels,and had protective effect on hepatic injury induced by SCCl₄.     

Pulmonary function, ventilator management, and outcome of dogs with thoracic trauma and pulmonary contusions: 10 cases (1994-1998)

OBJECTIVE: To document pulmonary function, ventilator management, and outcome of dogs with thoracic trauma that required mechanical ventilation because of severe pulmonary contusions. DESIGN: Retrospective study. ANIMALS: 10 dogs that required mechanical ventilation because of severe pulmonary contusions caused by blunt thoracic trauma. PROCEDURE: Signalment, historical data, arterial blood gas values, oxygen tension-based indices, ventilator settings, peak inspiratory pressure, positive end-expiratory pressure, tidal volume, and minute ventilation values were retrieved from medical records. RESULTS: All 10 dogs required positive-pressure ventilation because of dyspnea following trauma and had severely abnormal pulmonary function. Survival rate to discharge was 30%. Dogs were categorized into 2 groups; group A included 5 dogs in which pulmonary function improved during ventilation, whereas group B included 5 dogs that were euthanatized because of progressive lung dysfunction (n = 4) or cardiac arrest (1). Mean +/- SD body weight of group-A dogs (30.9 +/- 15.9 kg [68 +/- 35 lb]) was significantly greater than that of group-B dogs (7.6 +/- 1.8 kg [16.7 +/- 4 lb]). Dogs with improved lung function had peak inspiratory pressure that decreased progressively, whereas lung compliance deteriorated in dogs in group B. CONCLUSIONS AND CLINICAL RELEVANCE: Dyspneic dogs with severe pulmonary contusions may require and benefit from positive-pressure ventilation Prognosis is better for dogs that weigh > 25 kg (55 lb).     

Correlation of Serum Cardiac Troponin I and Myocardial Damage in Cattle with Monensin Toxicosis

Background: Cardiac troponin I (cTnI) is used as a biomarker of myocardial injury in people and small animals. Little is known about the diagnostic use of cTnI in cattle.
Hypothesis: Serum cTnI correlates to myocardial function and histopathologic lesions in cattle with monensin-induced myocardial injury.
Animals: Ten healthy cows.
Methods: Experimental study. Animals received 1 dose of monensin PO; 30 mg/kg (n = 1) or 40 mg/kg (n = 1) (Group A) or 50 mg/kg monensin (n = 8) (Group B) of body weight. Repeated measurements were performed of serum cTnI, biochemistry, and ECG and echocardiography until study termination at 80 (Group A) and 144 hours (Group B) after dosing. Semiquantitative histopathologic examinations of the heart were performed in each cow. A scoring system with regard to the magnitude of myocardial injury was established and a total heart score was compared with maximum cTnI concentration measured after monensin administration. Five hearts from healthy cows served as controls.
Results: Increased cTnI (>0.07 ng/mL) was found in 9/10 cows. cTnI was significantly associated with left ventricular shortening fraction ( r ²= 0.51; P = .02) and myocardial histopathologic lesion score ( r ²= 0.49; P = .021). All cows (n = 7) with evidence of myocardial necrosis had a cTnI concentration ≥ 1.04 ng/mL.
Conclusion and Clinical Importance: cTnI is related to myocardial necrosis and severity of myocardial damage in cattle with monensin toxicosis. cTnI could become a useful diagnostic tool in the noninvasive assessment of myocardial injury in cattle with naturally occurring cardiac disease.     

Use of standing low‐field magnetic resonance imaging to diagnose middle phalanx bone marrow lesions in horses

Bone marrow lesions (BMLs) (also known as ‘bone bruises’, ‘bone oedema’, ‘bone contusions’ and ‘occult fractures’) within the middle phalanx were diagnosed by standing low field magnetic resonance imaging (MRI) in 7 horses. The lesions were characterised by low signal intensity on T1‐ and T2*‐weighted gradient echo sequences, mildly increased signal intensity on T2 fast spin echo sequences, and high signal intensity on short tau inversion recovery (STIR) sequences. Four distinct patterns of abnormal signal were identified: BML associated with osteoarthritis of either the proximal or distal interphalangeal joints; BML associated with soft tissue injury; BML associated with acute trauma; and BML unassociated with any other injury or lameness (assumed to represent bone response to biomechanical stress). Repeat MRI was undertaken in 4 cases. In most cases the BML resolved with rest and time, although lameness was persistent in 2 horses (one of which had an associated osteoarthritis of the proximal interphalangeal joint).     

Comparative approach to understanding traumatic injury in the immature, postnatal brain of domestic animals

Traumatic brain injury (TBI) is a frequent occurrence in veterinary medicine, but the mechanisms leading to brain damage after a head impact are incompletely understood, particularly in the postnatal immature and still developing nervous system. This paper reviews neurotrauma studies, largely in paediatric humans and experimental animal models, in order to outline the pathophysiological and biomechanical events likely to be operative in head trauma involving domestic animal species in the postnatal period, as there is almost no other information available in the veterinary literature. Predicting the outcome of TBI is particularly difficult at this developmental time, in large part because recovery is influenced by the stage of brain maturation and neuroplasticity. An important part of the clinical management of TBI is the differentiation of primary brain damage, which occurs at the moment of head impact and is largely refractory to treatment, from the cascade of secondary events, which evolve over time and are potentially preventable and amenable to therapeutic intervention. An understanding of the causes and consequences of secondary brain damage such as hypoxia-ischaemia, brain swelling, elevated intracranial pressure, and infection is critical to limiting the resulting brain injury.     

Immunosuppressive effect of infectious pancreatic necrosis virus on rainbow trout (Oncorhynchus mykiss)

The infectivity of infectious pancreatic necrosis virus (IPNV) for rainbow trout (Oncorhynchus mykiss) mononuclear leukocyte subpopulations was investigated to determine the mechanisms of immunosuppression caused by the virus. IPNV was recovered from nylon wool-adherent, surface immunoglobulin (Ig)-positive leukocytes of head kidney, spleen and peripheral blood collected from virus-inoculated fish with higher titers than non-adherent, Ig-negative cells. Non-adherent cell population showed mitogenic response to phytohemagglutinin and concanavalin A but not to lipopolysaccharide. Conversely, the responses of adherent cells to these mitogens were weak. Mitogenic response and non-specific cytotoxicity of head kidney leukocytes significantly decreased by the inoculation of fish with the virus. These results suggest that the suppression of immune responses is involved in the establishment of carrier state in fish after infection with IPNV.     

Magnetic resonance imaging of the femoral head of normal dogs and dogs with avascular necrosis.

The purpose of this study was to describe the appearance of the femoral head of normal, young, small breed dogs, and dogs with avascular necrosis using low-field (0.3 T) magnetic resonance (MR) imaging. Images of the femoral heads were obtained in the dorsal plane, and included T1-weighted spin-echo, T2-weighted fast spin-echo, fast spin echo-inversion recovery, and fluid attenuated inversion recovery pulse sequences. MR imaging features of the asymptomatic femoral heads and necks included uniform high signal intensity compared with muscle on T1- and T2-weighted images. There was either uniform enhancement or no enhancement on postcontrast T1-weighted images. The MR imaging findings of dogs affected with avascular necrosis differed from those of asymptomatic dogs. Typically, the affected dogs had inhomogeneous intermediate to low-signal intensity within the femoral head and neck compared with muscle on T1-weighted images, inhomogeneous enhancement of the femoral head and/or neck on postcontrast T1-weighted images, and inhomogeneous low- to high- signal intensity within the femoral head and neck on T2-weighted images.     

Spontaneous and bilateral necrosis of the femoral head in a young experimental beagle dog

This report describes the pathological characterizations of a rare case of necrosis of the femoral head that was spontaneous, bilateral, avascular and nontraumatic. A 14-month-old beagle dog was presented with pain in the hind limbs. At necropsy, the articular surface in the bilateral femoral head was markedly irregular. There were no gross abnormalities other than in the hip joints. Microscopically, a wide range of trabecular bone necrosis localized in the subchondral area was observed in both femoral heads. In the right femoral head, fibrosis and proliferative vessels were noted in the subchondral area. The articular cartilage was thickened irregularly, but there was no evidence of cartilage necrosis. The bone marrow adjacent to the affected area showed severe depression. In the metaphysis, atrophic bone marrow, but not bone necrosis, was observed. This was a rare case of spontaneous necrosis of the femoral head in an experimental beagle dog.     

Pathophysiologic and immunologic changes in a canine endotoxemia over a period of 24 hours

In this study, the pathophysiologic and immunologic parameters from a 24-hr of canine endotoxemia model by lipopolysaccharide (LPS) infusion were evaluated. For that, twelve healthy beagles received a continuous 24-hr IV infusion of low dose LPS (10 μg/kg/h, from Escherichia coli serotype O111:B4) dissolved in saline. Complete blood counts and serum biochemical analysis as well as histopathologic examination were performed to assess pathophysiologic changes such as neutrophil migration and organ injury. To evaluate immunologic parameters, the concentrations of plasma tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 were determined, and neutrophil activation was also evaluated based on cell surface expression of CD11b using flow cytometry analysis. As results, systemic signs of endotoxemia including fever, vomiting, and hemorrhagic diarrhea were observed within short time after LPS infusion. Severe leukopenia and increased fluorescent intensity of CD11b on neutrophils were observed at 3 hr while percent positive of CD11b was the maximum at 12 hr during the experiment. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and creatinine phosphokinase (CPK) concentrations increased markedly, and organ damage was confirmed on histopathologic examination. Plasma TNF-α peaked at 3 hr and decreased rapidly, while the concentrations of IL-6 and IL-10 increased gradually until 6 hr and decreased thereafter. Using this canine endotoxemia model, we were able to determine the kinetics of pathophysiologic and immunologic parameters over a period of 24 hr. This study will enhance our understanding of their mechanisms underlying canine sepsis.     

Observations on femoral head abnormalities in broilers

Detachment of the proximal femoral cartilaginous epiphysis was observed in broilers that were being down-graded at slaughter as a result of haemorrhage into thigh musculature. A traumatic aetiology is proposed with injury occurring at catching. Examination of field case material, and birds culled from a commercial flock of the same strain, revealed that physeal lesions are not infrequent in proximal femora. Clefts and areas of matrix necrosis occurred in normal and dyschondroplastic physeal cartilage. Clefts were thought to result from repetitive minor trauma insufficient to cause total detachment of the cartilaginous epiphysis. Total detachment may result from an acute traumatic episode or be a consequence of pre-existing physeal lesions. A traumatic aetiology suggests that in such cases the terms fracture separation or traumatic epiphyseolysis of the cartilaginous epiphysis are more appropriate than femoral head necrosis or degeneration.     

Cerebello-olivary and lateral (accessory) cuneate degeneration in a juvenile American Miniature horse

A 12-month-old American Miniature horse colt was presented to the Virginia Tech Veterinary Teaching Hospital with a 7-month history of progressive ataxia. Physical examination revealed a head intention tremor, base-wide stance, and ataxia. Necropsy findings were confined to the brain. There were bilateral areas of liquefactive necrosis and cavitation corresponding to the dorsal accessory olivary and lateral (accessory) cuneate nuclei. Cerebellar folia of the dorsal vermis were thin. Microscopically, the cerebellar cortex was characterized by patchy areas of Purkinje cell loss with associated variable thinning of the molecular and granule cell layers and astrogliosis. Dorsal accessory olivary and lateral cuneate nuclei were cavitated and had mild glial response around their periphery. Additionally, a focus of necrosis and neuropil vacuolization was found in the right putamen. These findings indicate the presence of a neurodegenerative disorder centered, but not confined to, the cerebellum and its connections in this American Miniature horse colt.     

Cardiac arrhythmias associated with multiple trauma in dogs

Premature ventricular contractions and ventricular tachycardia were detected in 10 dogs 1 to 48 hours after trauma. All dogs were treated aggressively if the arrhythmias became severe. One dog died, 8 were discharged with stable cardiac rhythm, and 1 was euthanatized. Necropsy revealed gross and microscopic lesions of acute myocardial necrosis, probably of ischemic origin. Cardiac arrhythmias were associated with thoracic trauma, neurologic injury, severe shock, and/or extensive tissue trauma.