A RADIOGRAPHIC STUDY ON THE DEVELOPMENT OF THE ANTEBRACHIUM IN GREAT DANE PUPS, RAISED UNDER STANDARDIZED CONDITIONS

Radiographic examination of the antebrachium was performed in 16 healthy Great Danes, raised under standardized conditions, at six-week intervals from 9 to 27 weeks of age. The dogs were fed according to the National Research Council's nutrient requirements of dogs (1974). The development of the secondary ossification centers and the growth in length of the radius and ulna were noted. In the majority of dogs changes in the shape and structure of the distal ulnar metaphysis resembled disturbances in cartilage maturation and bone maturation and remodelling. An improvement in the radio-graphic appearance of the distal ulnar metaphysis was noted at the age of 27 weeks. It is concluded that the delicate processes that are involved in skeletal development may be frequently disturbed in fast growing, giant-breed dogs, without causing clinical problems.     

RADIOGRAPHIC EVALUATION OF PRENATAL DEVELOPMENT IN THE BEAGLE

The chronology of uterine enlargement and fetal mineralization relative to luteinizing hormone (LH) peak, time of breeding, and parturition was determined in six female Beagles. Uterine enlargement was first detectable radiographically 35 days prior to parturition. The uterus changes in shape from a circular to a tubular/ovoid structure by 24 days prior to parturition. Mineralized fetuses were first detected at 21 days prior to parturition. The extent of mineralization progressed rapidly with the proximal extremities, forelegs/hindlegs/pelvis, caudal vertebrae/paws, and finally, the teeth becoming visible at approximately 17, 11, five, and four days prior to parturition, respectively. There is a larger variation of gestational dates among dogs when based on time of breeding rather than on the occurrence of the LH peak or parturition. As such, the dates on which to radiographically detect uterine enlargement or fetal mineralization were more accurately determined when based on the occurrence of the LH peak or parturition instead of breeding dates.     

THE EFFECT OF OBLIQUITY ON THE RADIOGRAPHIC APPEARANCE OF THE TEMPOROMANDIBULAR JOINT IN DOGS

The temporomandibular joint is formed between the condyloid process of the mandible and the mandibular fossa of the temporal bone. The basic anatomy of this joint was assessed and described in a series of skulls including dolichocephalic, mesaticephalic and brachycephalic breeds. The facial index and rotational angles were measured with the facial index providing a useful method of classifying skull types but the rotational angle being of limited use in assessment of the temporomandibular joint until normal breed values are established. Equipment was designed to allow repeatable positioning of the temporomandibular joint for radiography at a variety of lateral and long axis rotational angles relative to the central x-ray beam. The regions of the joint and anatomic features visualized in each view are demonstrated. 10 degrees rotation was required in either axis to project the joints independently of each other. Lateral rotational angles of 10 to 30 degrees in mesaticephalic and dolichocephalic breeds and 20 to 30 degrees in brachycephalics and long axis rotational views of 10 to 30 degrees depending on the region of interest were considered to be the most useful.     

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.     

RADIOGRAPHIC FINDINGS IN THE THORAX OF DOGS WITH LEPTOSPIRAL INFECTION

Thoracic radiographs of 4 dogs with confirmed and 1 dog with suspected leptospirosis were reviewed. In all dogs a reticulonodular pulmonary opacity was noted, affecting the entire lung in 3 and predominantly the caudodorsal lung field in 2 dogs. The radiographic lung pattern described is associated with pulmonary hemorrhage probably due to endothelial damage and vasculitis. Pulmonary manifestations in dogs with leptospirosis may be misinterpreted and attributed to neoplasia, pneumonia, edema, hemorrhage due to disseminated intravascular coagulopathy, adult respiratory distress syndrome and pulmonary thromboembolism.     

RETROSPECTIVE ASSESSMENT OF THORACIC RADIOGRAPHIC FINDINGS IN METASTATIC CANINE HEMANGIOSARCOMA

Twenty-one dogs with histopathologically confirmed hemangiosarcoma were evaluated by thoracic radiography for metastatic disease. All dogs had histopathologic examinations of the lungs within two weeks of thoracic radiography. Fourteen dogs had histopathologic evidence of pulmonary hemangiosarcoma; metastatic disease was detected radiographically in eleven of these dogs. The most common radiographic pattern was that of poorly defined small coalescing nodules (8 dogs); other radiographic patterns included well-circumscribed nodules (3 dogs) and alveolar infiltrates secondary to hemorrhage (2 dogs). Differential diagnoses for diffuse, poorly defined, coalescing pulmonary opacities should include hemangiosarcoma in addition to edema, lymphoma, systemic mycoses, fibrosis, allergy, toxicosis, and carcinomas.     

RADIOGRAPHIC DETECTION OF DEFECTS OF THE NASAL BOUNDARIES

The sensitivity of conventional radiography for lesions of the cribriform plate, naso-orbital wall, lateral nasal wall and hard palate was investigated in 13 canine cadaver heads by creating measured defects in these structures. The location of the perforations were marked with a thin copper wire and the radiographic appearance of the defects was evaluated retrospectively by a single reviewer. Despite demarcation cribriform plate destruction of 2 mm could not be detected. Defects of 3 mm were detected in only 2 heads, 4 mm defects in 1 further head, an oblong 4 x 10 mm defect in 7 heads and in the remaining 3 heads only a 10 x 10 mm defect became visible as such. The naso-orbital wall had to be destroyed in its whole vertical length for detection of a defect in ventrodorsal or dorsoventral views. Therefore conventional radiography is of low diagnostic value for these lesions. Defects of 2 mm in the lateral nasal wall and the hard palate could be detected confidently in all heads indicating high sensitivity of conventional radiography. Soft tissue opacification did not alter the detectability of any nasal border structure lesion.     

RADIOGRAPHIC FEATURES OF AORTIC BULB/VALVE MINERALIZATION IN 20 DOGS

The radiographic features of aortic bulb/valve mineralization in 20 dogs were reviewed. Extent, shape, number, and location of mineralization were recorded. Five of the dogs had additional alternate imaging examinations, including bone scintigraphy, echocardiography, and thoracic computed tomography. A necropsy was done on one dog, and the area of mineralization was evaluated using routine histology. The median age was 10 (mean 9.7; SD +/- 2.7) years. There were five males, seven neutered males, one female, and seven neutered females. The breeds were: Irish setter (6); rottweiler (7); chow-chow (1); miniature dachshund (1); borzoi (1); English setter (1); English springer spaniel (1); great Dane (1); and greyhound (1). Dogs with both right and left lateral radiographs (n = 17) had mineralization visible on both views, more conspicuously on the right lateral radiograph (n = 12). Aortic bulb mineralization was identified on the ventrodorsal radiograph of only one dog. On lateral radiographs, the aortic bulb mineralization was localized within the 4th intercostal space and in the craniodorsal quadrant of the cardiac silhouette. In nine of the dogs, there were complex or multiple mineralizations and in 11 dogs, there was a single curvilinear mineral opacity oriented in a caudoventral to craniodorsal direction. In all radiographs, the mineralization was in the expected position of the aortic bulb, and echocardiography (n = 4), spiral computed tomography (n = 2), and necropsy (n = 1) confirmed that the mineralization was within the aortic bulb. Clinical pathologic data of the dogs suggested no reason for metastatic mineralization. Exact etiopathogenesis of the lesions were not determined in this study. Based on the histologic findings in one dog, the mineralization seen in the aortic root is similar to a form of dystrophic mineralization called Monckeberg's calcific arteriosclerosis in humans. No clinical signs attributable to the mineralization were observed.     

THORACIC RADIOGRAPHIC FEATURES OF ANTICOAGULANT RODENTICIDE TOXICITY IN FOURTEEN DOGS

Thoracic radiographs and clinical records from 14 dogs with confirmed anticoagulant rodenticide toxicity were reviewed. Twelve of the 14 dogs were presented with a chief complaint of respiratory distress, and 12 had elevated prothrombin and activated partial thromboplastin times consistent with a coagulopathy secondary to a clotting factor deficiency. Thoracic radiographs of the 14 dogs were reviewed and abnomalities included increased mediastinal soft tissue opacity with extra and intrathoracic tracheal narrowing (4/14), increased mediastinal soft tissue opacity without tracheal narrowing (8/14), variable degrees of pleural effusion (13/14) and generalized, patchy interstitial/alveolar pulmonary infiltrates (8/14). Radiographic evidence of cardiomegaly and pulmonary artery abnormalities consistent with concurrent heartworm infestation were detected in one dog. In four dogs, dramatic tracheal narrowing was identified on the lateral thoracic radiograph caused by either mediastinal hemorrhage compressing the trachea or submucosal hemorrhage within the tracheal lumen. The trachea was displaced in a ventral direction in two dogs, and extra and intrathoracic luminal diameter narrowing was evident cranially in all four dogs. Two of these four dogs had soft tissue opacity within the dorsal trachea that extended from the larynx to the intrathoracic trachea. Twelve of the 14 dogs survived with standard treatment protocols utilizing injectable and oral vitamin K₁. One dog died from pancreatitis and disseminated intravascular coagulopathy. The other dog died soon after presentation due to severe, disseminated hemorrhage. Follow-up thoracic radiographs were made in four dogs that survived and showed resolution of the mediastinal, pleural and pulmonary changes within one to five days after the initiation of vitamin K₁ therapy.     

生长期莎能奶山羊能量代谢研究──Ⅲ.不同环境温度、不同体重和不同代谢能采食量对生长期莎能奶山羊日增重的影响

本研究用15头生长期西农莎能如山羊（平均日龄为134.5±5．7天，平均体重为18．7±1．05kg），随机分为5组，分别按自由来食，0．89860．7189和0．5391MJME／kgW0.75等4个能量水平进行两期饲养试验，测定各能量采食水平组的体重、干物质和能量采食量，并计算出各组羊平均日增重。结果表明，生长期莎能奶山羊每公斤代谢你重日增重与奶山羊的体重大小无关，其主要影响因素是干物质和能量采食量，特别是有效能采食量。同时，低温环境引起生长期莎能奶山羊口增重显著下降。     

A RETROSPECTIVE EVALUATION OF THE RADIOGRAPHIC EVIDENCE OF PULMONARY METASTATIC DISEASE ON INITIAL PRESENTATION IN THE DOG

Thoracic radiographs of 346 dogs, diagnosed as having primary neoplasms, were reviewed for radiographic changes associated with pulmonary metastatic disease at the time of initial presentation. Dogs having radiographic changes of single or multiple interstitial nodular opacities, in the absence of concurrent intrathoracic disease, were considered to have pulmonary metastatic disease. The frequency of metastasis associated with each histologic tumor type was compared by chi-squared analysis. Dogs having primary thyroid carcinomas and transitional cell carcinomas demonstrated the greatest frequency of radiographic changes, 62.5% and 26% respectively. In dogs having a variety of other neoplasms, including nasal adenocarcinomas and cutaneous neoplasms, thoracic radiography proved useful in delineating intercurrent disease and staging, as well as the extent of neoplastic involvement. These results indicate early radiographic evaluation of the thorax should be performed on all dogs with confirmed or suspected primary neoplasms.     

THE RADIOGRAPHIC APPEARANCE OF PULMONARY HISTOPLASMOSIS IN THE CAT

A retrospective study of 18 cats with pulmonary histoplasmosis was conducted to evaluate radiographic patterns of disease and to determine age, breed, and sex distributions. All cats had active disease confirmed by biopsy/aspiration cytology (lung, bone marrow, peripheral lymph nodes, pleural fluid) or necropsy examination. Cats 3 years of age or less had the highest incidence of disease; females outnumbered males 2 to 1. Radiographically, most cats had an interstitial pattern which appeared as a fine, diffuse or linear pattern, or as a more distinct nodular pattern. An alveolar pattern was an uncommon radiographic finding. Tracheobronchial lymphadenopathy and calcified lymph nodes or pulmonary parenchymal lesions were not identified in these cats.     

RADIOGRAPHIC ANATOMY OF THE CRIBRIFORM PLATE (LAMINA CRIBROSA)

The radiographic appearance of the cribriform plate was investigated in 16 canine cadaver heads. The cribriform plate appeared as a "V"-shaped multilinear bone-opaque stripe in the caudal nasal region in projections perpendicular to the hard palate in 6 dogs with a skull index between 50.00 and 54.00. In 9 dogs with a skull index between 55.40 and 74.40, the cribriform plate had a more "C"-shaped and sharp appearance. In vertically oblique projections with an obliquity greater than 20 degrees, the cribriform plate lost its sharp outline and finally (40 degrees) disappeared. In lateral projections the cribriform plate appeared as a "C"-shaped interrupted bone-opaque stripe in all 16 dogs. In more brachycephalic dogs frontal bone structures superimposed on the cribriform plate on ventrodorsal and dorsoventral views and accentuated the radiographic appearance of the plate. Vertically oblique views separated both structures to produce two lines.     

RADIOGRAPHIC ANATOMY OF THE CANINE COXOFEMORAL JOINT USING THE DORSAL ACETABULAR RIM (DAR) VIEW

A radiographic study of the anatomy of the canine acetabulum was performed. The relationship between the area of dorsal acetabular rim that is subject to early damage in dogs with coxofemoral joint laxity, and the "DAR point" identified on dorsal acetabular rim (DAR) radiographic views was examined. Radiographs and digital photographs were made of the pelvis harvested from each of six skeletally mature dogs. Through analysis of these images, it was determined that in the standing animal, the DAR point is located 4–6 mm (or approximately 37°) caudal to the dorsal acetabular rim area that is prone to early damage in dogs with coxofemoral joint laxity. This study suggests that the DAR radiographic view may under-represent changes to the dorsal acetabular rim in dogs with coxofemoral laxity.     

THE NATURE AND RADIOGRAPHIC PATTERNS OF PERIOSTEAL RESPONSE IN THE BOVINE

Seventy-five bovine radiographic examinations with definite periosteal response were analyzed for quality and pattern of new bone formation. Three patterns were recognized — amorphous, lamellar, and spiculated; they appeared singly or in various combinations. The lamellar and amorphous types seemed to be generally bone-related: with lamellar predominantly in the metacarpal and metatarsal bones and amorphous in the phalanges. The spiculated pattern in the bovine does not seem to be related to neoplastic processes. Bovine periosteum responded rapidly and with high magnitude.     

乳牛口服过量维生素A对维生素D3及钙磷代谢的影响

从北京郊区某农场选取１０头健康成年黑白花乳牛，随机分为试验（５头，每周每头口服维生素Ａ１００万单位）和对照（５头，不作任何处理）两组。８周以后检测发现，试验组血清钙和无机磷水平呈下降趋势；尾椎骨皮质变薄，密度下降，呈现骨质吸收现象；血清碱性磷酸酶显著下降（Ｐ＜０．０５）；其活性代谢产物２５－羟维生素Ｄ３（２５－ＯＨ－Ｄ３）极显著下降（Ｐ＜０．０１）；１，２５－二羟维生素Ｄ３［１，２５－（ＯＨ）２－     

SENSITIVITY OF RADIOGRAPHIC DETECTION OF LUNG METASTASES IN THE DOG

Thoracic radiographs were taken in right lateral recumbent (RLR), left lateral recumbent (LLR), and ventrodorsal (VD) projections in 80 dogs with known or suspected malignant tumors. Radiographs in each projection were interpreted, independently of those in the other two projections, by four veterinary radiologists, and classified as positive or negative for one or more lung metastases. The four radiologists then met, to agree on a diagnosis for each patient by simultaneously reviewing all three views. This panel diagnosis became the standard for subsequently classifying individual views as either true positive or true negative. As determined by a consensus of the panel, 25 dogs had at least one positive thoracic radiograph.
The three radiographic projections differed in sensitivity for the detection of lung metastases. In this study, the RLR view was the most sensitive, and the VD view the least sensitive. The sensitivity of detection improved significantly with multiple readers. From these data we recommend that, for detection of lung metastases in the dog, the RLR view be included in any diagnostic protocol; a minimum of two readers be used; and a three-view protocol be used if only one reader is available.     

RADIOGRAPHIC DIAGNOSIS OF GASTROINTESTINAL DISORDERS IN THE FOAL

Abdominal discomfort in the foal presents a diagnostic challenge, because the small size of the foal precludes rectal palpation. Standing lateral horizontal beam abdominal radiographs using conventional techniques were evaluated as a diagnostic aid to identify the presence and location of gastrointestinal disorders in foals presented with colic. Forty foals were radiographed prior to surgery (20 foals), necropsy (7 foals), or clinical diagnosis (13 foals). Clinical, surgical, or necropsy findings were then correlated to radiographic findings. Gastrointestinal disease was accurately identified on radiographs as the source of colic in 25 of 26 foals that had surgical or postmortem confirmation. The site of disease, whether gastric, small intestinal, large intestinal, or a combination, was accurately determined from radiographs. Standing lateral abdominal radiographs were determined to be a valuable diagnostic aid in the foal presented with colic.     

RADIOGRAPHIC STUDY OF DISTAL RADIAL PHYSEAL CLOSURE IN THOROUGHBRED HORSES

Monthly radiography was performed to study distal radial physeal closure in ten male and ten female Throughbred horses. The height, thoracic circumference and metacarpus circumference were also measured. Distal radial physeal closure time was sooner in females than males, and took 701 ± 37 and 748 ± 55 days respectively.