THE EFFECT OF POSITIONING ON THE APPEARANCE OF SELECTED CRANIAL THORACIC STRUCTURES IN THE DOG

In this retrospective study the effect of thoracic positioning on the visibility and size of selected cranial thoracic structures in dogs was investigated. Dorsoventral (DV), ventrodorsal (VD) as well as left lateral recumbent (LLR) and right lateral recumbent (RLR) thoracic radiographs of 17 large, 15 medium, and 10 small skeletally mature dogs were evaluated. The craniodorsal and cranioventral mediastinum, the cupula pleura and sternal lymph nodes were examined. The effect of obesity was also evaluated. The craniodorsal mediastinum was better delineated on DV radiographs and was wider on VD radiographs. The craniodorsal mediastinal width: width of T2 cranial end-plate on VD radiographs was 2.41 for all groups combined and obesity significantly influenced this value. The cranioventral mediastinum was more visible in RLR and VD radiographs. A normal sternal lymph node soft tissue opacity was seen most commonly in RLR in large breed dogs and had a mean length of 30 mm. The pulmonary cupula extended beyond the first rib on all views and extended more cranially and was better visualised on VD than DV views.     

Measurement of the back fat layer in beagles for estimation of obesity using two-dimensional ultrasonography

The purpose of this study was to select a suitable location for measuring the subcutaneous fat layer in beagles as an indicator of excess body fat deposition. A location suitable for such a measurement should meet five conditions--it should be easy to: (1) apply the probe, (2) detect the anatomical character of the measurement location, and (3) obtain a reproducible ultrasonogram at all times. In addition, the fat layer should be (4) thick enough for measuring, and (5) located in an area that varies markedly with the degree of obesity. Ultrasonograms made in the transverse planes on the top of the spinous process of the sixth lumbar vertebra, the seventh lumbar vertebra and the first sacral vertebra were found to be suitable for measurement. The depth and area of the back fat layer at these locations were closely related to the degree of obesity.     

Radiography and computed tomography of the heart and lower respiratory tract in toco toucans (Ramphastos toco)

This study aimed to evaluate normal features of the heart and lower respiratory tract in toco toucans by means of radiography and helical computed tomography (CT) scanner. Fifteen healthy adult toco toucans (Ramphastos toco), 10 females and 5 males, average body mass of 650 g were studied. CT examination as well as right lateral and ventrodorsal radiographic examinations of the coelomic cavity were performed under chemical restraint. Heart, lungs, air sacs, trachea and syrinx were analysed. The mean values of heart length, heart width and thoracic cavity in radiographs were, respectively, 23.76 mm, 25.94 mm and 48.87 mm. In both X-rays and CT scans, the lung parenchyma had honeycomb-like pattern. The topographic areas of the anterior and posterior air sacs were visualized as dark and air-filled spaces in X-rays. On CT evaluation, the air sacs occupied a larger area in the coelomic cavity compared to X-ray. In the lateral radiographic view, the cervical part of the trachea was positioned more ventrally in the transition from cervical to thoracic regions showing a V-shaped appearance. In all CT planes was visible division of the trachea into the right and left main bronchi at the level of 3rd thoracic vertebra. The syrinx was difficult to visualize in X-rays, but on CT it was easily identified in axial slice. In conclusion, the normal features of toco toucan's heart and lower respiratory tract that were determined on X-rays and CT scans are useful to compare with sick toco toucans, as well as other bird species.     

Radiographic evaluation of cardiac size in flying fox species (Pteropus rodricensis, P. hypomelanus, and P. vampyrus).

Dilated cardiomyopathy is a relatively common pathology in captive flying foxes (Pteropus spp.). The goal of this study was to establish quantitative reference range measurements that could be used to support a diagnosis of cardiac disease in these animals. Lateral and ventrodorsal thoracic radiographs from apparently healthy flying foxes (n = 66) of three species (Rodriguez island flying fox, P. rodricensis, n = 18; small island flying fox, P. hypomelanus, n = 16; and Malaysian flying fox, P. vampyrus, n = 32) were evaluated objectively to describe the cardiac appearance. Absolute and relative cardiac dimensions also were measured. The same methods were used to evaluate radiographs from flying foxes (n = 9) with known dilated or acute cardiomyopathy. The following ratios were most appropriate for categorizing normal cardiac silhouette size. In the ventrodorsal projection, heart width to thoracic width and heart width to clavicle length were the preferred measurements. In the lateral projection, heart width compared with thoracic height was the preferred measurement. From radiographs of the bats with known dilated and acute cardiomyopathy, the apicobasilar heart length compared with thoracic height and heart width compared with thoracic height on lateral films were the most sensitive ratios for diagnosing cardiomegaly.     

Cardiac measurements on thoracic radiographs of cats

Measurements of the heart and thorax were made on lateral and ventrodorsal thoracic radiographs of normal cats. The degree of correlation between selected cardiac and thoracic measurements was determined. Absolute measurements and ratios of measurements in normal cats and in cats with certain cardiac diseases were compared and their diagnostic value was evaluated. It was concluded that on the lateral thoracic radiograph the ratio of the cranio-caudal width of the heart to the distance between the cranial border of the fifth rib and the caudal border of the seventh rib was a highly reliable indicator of cardiac enlargement. On the ventro-dorsal radiograph the ratio of the maxium width of heart to the width of the thorax at the same level was the best indicator of increases in cardiac size.     

紫花苜蓿幼苗生长及其叶片形态对水分胁迫的响应

试验旨在研究紫花苜蓿(Medicago sativa L.)生物量、水分生理状态以及叶片形态对水分胁迫的响应并确定参试紫花苜蓿品种的御旱能力。通过温室盆栽试验,对3个品种的紫花苜蓿进行了4个梯度的水分胁迫处理,测量了根干重、茎干重、叶干重、叶水势、相对叶片含水量、叶长、叶宽、叶面积以及相关指标的胁迫指数。结果显示:紫花苜蓿根、茎、叶的干重对水分胁迫的响应依品种和胁迫程度的不同而不同;随着水分胁迫程度的增加,根冠比呈增大趋势;叶水势、叶片相对含水量、根系含水量胁迫指数以及叶片含水量胁迫指数均呈下降趋势;叶片变短变窄,叶面积变小,比叶面积胁迫指数呈下降趋势。3个紫花苜蓿品种中‘敖汉’的根冠比最大且比叶面积胁迫指数最小,其御旱能力最强,‘中苜1号’次之,‘三得利’最弱。     

纤维素复合酶对羔羊消化道组织结构的影响

为了探明纤维素复合酶提高羔羊饲料消化率的消化道组织学基础,选择刚出生且体重相近的波尔山羊公羔30只(20日龄开始自由采食优质苜蓿干草, 80日龄断奶)分为对照组和试验组(添加0.2%酶制剂),分别在2、3和4月龄每组各选体重相近的3只羔羊屠宰.结果表明,瘤胃乳头长度、宽度和单位面积瘤胃乳头表面积随月龄增加而增加,而单位面积乳头数随着月龄的增加而减少(P ＜ 0.01).酶制剂提高3、4月龄羔羊瘤胃乳头长度(P ＜ 0.01)、宽度(P ＞ 0.05)和单位面积瘤胃乳头表面积(P ＜ 0.01),减少单位面积乳头数(P ＜ 0.01).显著提高3月龄十二指肠肠绒毛的长度(P ＜ 0.05).在3、4月龄,酶制剂有增加小肠隐窝深度和黏膜厚度的趋势,但未达到显著水平(P ＞ 0.05).     

Measurements of the bodyweight and other physical characteristics of 11 llamas (Lama glama) from birth to weaning

The bodyweight (bw), thoracic circumference, length and height of 11 llamas were recorded weekly from birth for 27 weeks. Their mean (sd) birth weight was 11.60 (2.35) kg and their weight increased in curvilinear fashion reaching 61.05 (13.75) kg after 27 weeks. Their average daily gains reached the highest value three weeks after birth and then decreased, reaching the lowest value of 262 g per day at 27 weeks. On a metabolic bw(0.83) basis, the growth of the llamas when their dams were at peak lactation was comparable with that of calves, fawns and lambs. All the measurements were significantly affected by the age, but not by the sex of the young or the parity of the dam. The regression models chosen to predict the bodyweight and weight gain of the llamas yielded R(2) ranging from 0.97 to 0.99. Correlations between bodyweight and other single body measurements were between r=0.68 and 0.77. Single or combined body measurements were good predictors of bodyweight, but additional body measurements added little to the already good fit provided by a single measurement (R(2) ranging from 0.93 to 0.98). The thoracic circumference (R(2)=0.98) and length (R(2)=0.96) were good predictors of the bodyweight of the llamas between birth and 27 weeks old.     

Thoractic radiographic appearance during lung inflation in neonatal calves

The effect of lung inflation on thoracic radiographic anatomy was determined in seven anesthetized calves less than one week of age. Radiographs were taken with the calves in dorsoventral (DV), ventrodorsal (VD), left and right lateral recumbency at functional residual capacity (FRC), at half inflation of the lung and at total lung capacity (TLC). Lung volumes were maintained by positive pressure ventilation. Increases in areas and linear dimensions during lung inflation were not uniform, being greatest in the caudal and especially the caudal ventral regions of the thorax. With inflation, heart size decreased and the heart shadow moved cauded as the diaphragm flattened. When the calf was shifted from the DV to the VD position, the heart displaced toward the left thoracic wall. Lung areas were larger on VD than on DV projections with the right lung being larger than the left. On lateral radiographs the most reliable, easily observed indication of the stage of lung inflation was the area bounded by the vena cava, the caudal heart border and the diaphragm. On the DV or VD radiographs the transthoracic width at the diaphragm was the best indicator of the degree of lung inflation.     

Re‐induction of obese body weight occurs more rapidly and at lower caloric intake in beagles

For the purpose of investigating the mechanism of obesity‐induction/re‐induction including weight‐cycling in beagles, a study was conducted using commercially available dog food combined with human food to mimic at home‐snacking and diet‐supplementation behaviours. Adult female beagles, which had free access to water and exercise, were used (n = 9). All dogs were initially offered two times their daily calculated number of calories using a dry extruded diet plus blend of canola and soybean oils and allowed to eat ad libitum. After 3 weeks, Pecan shortbread cookies were added to the diet mixture. Obesity was induced during a 19‐week period with 1875–2250 kcal/day consumed, on average, during this period. The dogs were then subjected to a weight‐loss regimen while consuming 490–730 kcal/day. After weight loss, a similar degree of obesity was re‐induced for 17 weeks even though dogs consumed only 1125–1250 kcal/day. Body weight, body condition scores, kcal consumption and food efficiency were recorded. Results indicated that less time and fewer kcal were required to re‐induce the same degree of obesity compared with the initial obesity induction. Human snack foods appeared to stimulate appetite and thus contribute to the obese state. Food efficiency was also increased during the obesity‐reinduction period compared with the induction period. This information may help pet owners better understand the need to limit table scraps and human‐type food snacks in dogs prone to obesity as well as weight maintenance after weight loss.     

RADIOGRAPHIC CHARACTERIZATION OF PRESUMED PLATE‐LIKE ATELECTASIS IN 75 NONANESTHETIZED DOGS AND 15 CATS

Discrete discoid or linear areas of increased soft opacity have been observed within the pulmonary parenchyma in thoracic radiographs of dogs and cats. Similar radiographic findings have been described in humans and termed plate‐like atelectasis. The purpose of this retrospective study was to describe locations and characteristics of presumed plate‐like atelectasis, presence of concurrent thoracic disease(s), and presence of persistent pulmonary changes on recheck thoracic radiographic studies in a cohort of dogs and cats. Hospital records between 2004 and 2011 were searched and a total of 90 cases were included (75 dogs and 15 cats, 2–17 years of age). Plate‐like atelectasis was most commonly found in left lateral radiographs. Plate‐like atelectasis was observed in the cranial thorax and was oriented in a dorsocranial to ventrocaudal direction in 68 (75%) patients. Plate‐like atelectasis averaged 29.6 ± 14.4 mm in length and 2.6 ± 1.3 mm in width. In 57 of the 90 patients (63%), plate‐like atelectasis was the only abnormality found. Plate‐like atelectasis was present in 7 of 22 cases where follow‐up radiographs were available. Findings from the current study indicated that, while the etiology of plate‐like atelectasis remains unknown, anatomic variations in sublobar pulmonary anatomy might account for pleural areas of atelectasis. The authors propose that the presence of plate‐like atelectasis may represent areas of atelectasis that track along sublobar lung lobe separations, an area of hypoventilation or decreased collateral ventilation, and/or area of decreased localized surfactant deficiency.     

Partial lateral corpectomy of the thoracolumbar spine in 51 dogs: assessment of slot morphometry and spinal cord decompression

Objective: To report slot morphometry, degree of spinal decompression, and factors influencing decompression after partial lateral corpectomy (PLC) of the thoracolumbar spine in dogs with intervertebral disc disease. Study Design: Case series. Animals: Dogs (n=51) with predominantly ventrally located spinal cord compression. Methods: PLC (n=60) were performed. Spinal cord compression was determined by computed tomographic (CT) myelography (n=46), myelography (n=2) or magnetic resonance imaging (n=3). Postsurgical CT images were used to evaluate slot dimensions and orientation, and spinal cord decompression. The influence of age, body weight, breed, breed type (chondrodystrophic, nonchondrodystrophic), disc location, lateralization and mineralization, presurgical compression, slot morphometry, and surgeon on degree of decompression were evaluated. Results: Mean slot depth was 64.1% of vertebral body width; mean height, 43.0% of vertebral body height; mean cranial extension, 29.5%; median caudal extension, 22.0% vertebral body length; mean angulation from horizontal, 6.3°. Decompression was satisfactory in 90% of sites after PLC (58% complete, 32% good). None of the analyzed factors significantly influenced decompression. All lumbar spine PLC resulted in complete or good decompression compared with 83% after thoracic PLC (P=.052). Deeper slots tended to allow more complete decompression (P=.058). Conclusions: Thoracolumbar PLC results in satisfactory decompression in most cases with a better outcome in the lumbar spine than the thoracic spine. Achieving a slot depth equal to 2/3 of vertebral body width might facilitate complete decompression.     

Bromide-associated lower airway disease: a retrospective study of seven cats

Seven cats were presented for mild-to-moderate cough and/or dyspnoea after starting bromide (Br) therapy for neurological diseases. The thoracic auscultation was abnormal in three cats showing increased respiratory sounds and wheezes. Haematology revealed mild eosinophilia in one cat. The thoracic radiographs showed bronchial patterns with peribronchial cuffing in most of them. Bronchoalveolar lavage performed in two cats revealed neutrophilic and eosinophilic inflammation. Histopathology conducted in one cat showed endogenous lipid pneumonia (EnLP). All cats improved with steroid therapy after Br discontinuation. Five cats were completely weaned off steroids, with no recurrence of clinical signs. In one cat, the treatment was discontinued despite persistent clinical signs. The cat presenting with EnLP developed secondary pneumothorax and did not recover. Br-associated lower airway disease can appear in cats after months of treatment and clinical improvement occurs only after discontinuing Br therapy.     

CHANGES IN THE CANINE FEMOROPATELLAR JOINT SPACE IN THE POSTSURGICAL, CRUCIATE-DEFICIENT STIFLE JOINT

In this study, we investigate the factors that influence changes in articular cartilage thickness in naturally occurring osteoarthritis of the canine stifle joint. Fifty-eight dogs with QA secondary to cranial cruciate ligament deficiency were examined radiographically at 0, 7, and 13 months using 90 degree flexed mediolateral radiographs of both stifle joints. The femoropatellar joint space widths were measured using a computer-assisted video image analysis system. The femoropatellar joint space widths were found to be significantly increased in index joints as compared to contralateral joints. In addition, there was a significant increase in femoropatellar joint space (FPJS) width over the course of the study, particularly between entry and 7 months. Factors that might influence the degree of femoropatellar joint space increase (bodyweight, age, sex, disease duration, radiographic score) were investigated using regression analysis. Body weight at baseline showed a moderate to strong relationship with change in FPJS between 0 and 7 months (Pearson's partial correlation r = 0.417, p = .006). This relationship was less strong for change in femoropatellar joint space between 7 and 13 months (r = 0.324, p = .036).     

RADIOLOGICAL ASSESSMENT OF THE RELATIONSHIP BETWEEN THORACIC CONFORMATION AND THE RISK OF GASTRIC DILATATION-VOLVULUS IN DOGS

To test the hypothesis that breeds of dogs with a deeper and narrower thorax have an increased risk of gastric dilatation-volvulus (GDV), thoracie depth, width, and length were measured for 437 dogs of 17 different breeds using radiographs on file at the Veterinary Teaching Hospital of the Purdue University School of Veterinary Medicine for the period of 1977 to 1993. These data were applied to risk estimates of GDV that were generated from a separate case control study using the Veterinary Medical Data Base. Multiple linear regression analysis was used to relate the mean thoracie measurements and the ideal, adult body size of the breeds to the risk of each breed developing GDV. When the risk of GDV was evaluated as a function of the mean thoracie depth/width ratio alone, or as a function of the thoracie depth/width ratio plus ideal adult breed weight, 37% (p = 0.022), respectively, of the variability in GDV risk was explained. These findings support the hypothesis tested and suggest that selective breeding can be used to decrease a breed's risk of GDV over time.     

THE EFFECT OF DORSAL VERSUS VENTRAL RECUMBENCY ON THE RADIOGRAPHIC APPEARANCE OF THE CANINE THORAX

The thorax of nine dogs was radiographed with a vertical beam in both dorsal (VD) and ventral (DV) recumbency. The radiographs were evaluated subjectively and objectively for differences in appearance. To help explain appearance differences, lateral thoracic radiographs were made with the dogs in dorsal and ventral recumbency using a horizontally (laterally) directed x-ray beam. The appearance of thoracic viscera in VD and DV vertical beam radiographs differed. In VD vertical beam radiographs the craniocaudal axis of the heart appeared longer, the heart had a more consistent positional relationship to the thoracic spine, a larger area of the accessory lung lobe was visible, and a greater length of the caudal vena cava was visible. In DV radiographs the caudal lobar pulmonary arteries were more easily identified. The selection of dorsal versus ventral recumbency for thoracic radiography should be based on the clinical status of the patient and the reason(s) for which the radiograph is being made.     

如皋鸡生长发育规律和体尺性状研究

本试验对0～12周龄如皋鸡的体重生长规律及12周龄体尺性状进行了研究。结果表明：①1～12周龄公母鸡间体重存在极显著差异（P<0.01），公鸡的体重整齐度较差；②Gompertz模型能很好地描述鸡体重生长模式（R2＞0.996）,其生长拐点在6～7周龄，如皋鸡成熟体重和生长高峰体重的遗传力均为0.09，初生重估计值、平均生长速率、生长高峰周龄的遗传力分别为0.21、0.32、0.37；③用全同胞和半同胞2种遗传模型估计的体重方差组分及遗传力结果有明显差异。用全同胞遗传模型计算的公鸡体重遗传力明显高于母鸡（都是高遗传力），体重遗传力总体上随饲养周龄的增长呈下降趋势，随周龄增加母本效应越来越小，并且公鸡受母本效应的影响明显大于母鸡，用半同胞遗传模型计算的公鸡体重遗传力7周龄前小于母鸡，8～9周龄等于母鸡，10～12周龄大于母鸡；④12周龄体尺性状中除胸角性别间差异不显著（P>0.05）、公鸡胫色显著黄于母鸡（P<0.05）外，其他性状均为公鸡极显著大于（红于）母鸡（P<0.01）；⑤12周龄胸角与其它体尺性状表型相关都不显著（P>0.05），其余绝大部分性状间存在显著（P<0.05）或极显著（P<0.01）相关。⑥活重、体斜长、龙骨长、胫长、胫围、冠长、冠高、冠色、胫色、胸角、胸宽的遗传力分别为0.53、0.11、0.64、0.92、0.42、0.16、0.15、0.52、0.25、0.16、0.40。     

果实性状在梨杂交F1代的遗传变异和相关性分析

以4个杂交组合的539株梨杂交F1代单株为试材,开展了梨果实性状在杂交过程中的遗传变异及性状间的相关性研究。结果表明：果形、风味和单果重等性状在F1代的变异较大,属于高变异性状,而萼洼宽度、果肉类型、纵径、横径和可溶性固形物含量等性状的变异较小,属于低变异性状,单果重和果形在F1代的变异情况受杂交亲本影响较大,梗洼深度、果心大小和横径的变异受杂交亲本的影响较小;果实纵径、果实横径和可溶性固形物含量在F1代呈正态分布,分级描述性状在各个表型的分布不均匀;相关性分析发现单果重与横径,单果重与纵径,横径与纵径、果肉类型与果肉硬度、果形与纵径、萼洼深度与萼洼宽度,梗洼深度与梗洼宽度等性状间均具有较高的相关性。研究结果可以为梨杂交育种正确合理地选择育种亲本、提高育种效率提供理论依据。     

Ultrasonographic estimation of prostate size in normal dogs and relationship to bodyweight and age

A study was undertaken to establish the ranges of prostate dimensions, weight and volume in mature normal dogs and thus provide information which would allow differentiation from normality of size changes associated with disease. The study was performed on 154 healthy adult male entire dogs. Each prostate was imaged ultrasonographically and standard longitudinal and transverse sections were obtained. Prostate length (L), depth on longitudinal (DL) and transverse sections (DT) and width (W) were measured. Prostatic volume and weight were estimated according to formulae derived previously. There were statistically significant correlations between bodyweight or age and L, DL, DT and W. There were also significant correlations between estimated prostatic weight or volume and bodyweight, age, L, DL, DT and W. Formulae were derived to express the relationships between prostate size (weight or volume) and age or bodyweight.     

Estimation of the volume of the gall bladder of 32 dogs from linear ultrasonographic measurements

The maximum length and depth of the longitudinal section, and the maximum width and depth of the transverse section of the gall bladders of 32 dog cadavers were measured ultrasonographically; the contents of the gall bladder were then aspirated and its actual volume measured. The volume of the gall bladder was estimated from the ultrasonographic measurements by using formulae suggested for assessment of the volumes of the urinary bladder in human beings and the gall bladder of dogs, and these formulae were compared with a formula derived from the measurements made in this study. In 21 of the dogs, the measurements were repeated twice so that their reproducibility could be evaluated. All the formulae gave good estimations of the volume of the dogs' gall bladders, but the formula for the human urinary bladder volume was better than the other two. The actual volume of the gall bladder was related to the dogs' bodyweight. There were no significant differences between the repeated measurements of the maximum length and depth of the longitudinal section or the width of the transverse section of the gall bladder, but there were significant variations in the depth of the transverse section.