ULTRASOUND-ASSISTED DIAGNOSIS OF RENAL DYSPLASIA IN A 3-MONTH-OLD QUARTER HORSE COLT

A 3-month-old foal was presented for correction of bilateral angular limb deformities. Azotemia was detected as an incidental finding. Small, misshapened, hyperechoic kidneys with decreased corticomedullary demarcation were noted with ultrasonography. Additionally, the internal renal architecture was abnormal in that the intrarenal vessels and distant collecting system were not clearly seen in either kidney. Ultrasound-guided renal biopsy was suggestive of congenital renal dysplasia, which was later confirmed at necropsy. Clinical, sonographic, and pathologic features of equine renal dysplasia are discussed.     

HEMANGIOMA OF THE DISTAL PHALANX IN A COLT

A yearling Thoroughbred colt was admitted to the University of Florida College of Veterinary Medicine with severe, progressive lameness of the left forelimb. A centrally located expansile lytic lesion involving approximately 40% of the distal phalanx with a large associated vascular channel was identified by radiography. Increased vascular phase pooling, increased soft tissue phase uptake, and a photopenic area on bone phase images corresponding to the lytic lesion within the left distal phalanx were identified by vascular, soft tissue, and bone phases of a three phase bone scan, respectively. Contrast medium accumulation and disappearance in dilated vessels within the lesion was apparent angiographically. The colt was euthanized and the histologic diagnosis was hemangioma of the distal phalanx with a pathologic fracture.     

COMPUTED TOMOGRAPHY OF ASPIRATION PNEUMONIA IN A DOG

A dog with aspiration pneumonia was examined by computed tomography (CT) with 8-mm continuous scans of the chest. The results demonstrated that CT is a useful procedure for evaluating pneumonia, although high cost prevents its routine use. A normal littermate was examined, and normal structures of the chest and chest wall were compared.     

二氟沙星对实验性感染猪链球菌病及支原体性肺炎的药效学研究

本文报道国内新近研制的畜禽专用氟喹诺酮类抗菌药物－二氟沙星对实验性感染猪链球菌病及支原体性肺炎的药效学研究。以试管两倍稀释法测得二氟沙星对兰氏C群类马链球菌（C55120）和猪肺炎支原体（F16株）的最小抑菌浓度（MIC）分别是1．6级及0．16mg/L。肌注给药对猪链球菌病和支原体性肺炎的实验性治疗结果表明，低、中、高剂量二氟沙星组（2．5、5、10mg/kg)及恩诺沙星组（2．5mg/kg)用药5d（每隔12h给药1次）对猪链球菌病的治愈分别是40％、70％、80％及70％，而链球菌感染对照组的死亡率为70％；低、中、高剂量二氟沙星组及恩诺沙星组（2．5mg/kg)用药5d（每隔12h给药1次）对猪支原体性肺炎的治愈率分别是80％、90％、90％及80％；而支原体感染对照组的自愈率为10％。     

PRESUMPTIVE TENOSYNOVIAL OSTEOCHONDROMATOSIS IN A HORSE

A 5 year old Arabian mare was evaluated for a non-painful swelling located dorsal to the right carpus which had been present for 2 years. Radiographically, multiple mineralized bodies were identified dorsal to the distal radius and carpus in the region of the tendon sheath of the extensor carpi radialis muscle. The radiographic appearance of the carpal bones was within normal limits. On ultrasound examination, multiple hyperechoic foci with posterior shadowing were seen adjacent to the extensor carpi radialis tendon. There was minimal distension of the tendon sheath and no abnormalities within the substance of the extensor carpi tendon were identified. Considering the radiographic and sonographic findings, a presumptive diagnosis of tenosynovial osteochondromatosis was made. Histological confirmation of this diagnosis was not obtained as the owner declined further diagnostic evaluation.     

氨苯枫——联磺甲氧苄啶对实验猪卡氏肺孢子虫肺炎的疗效试验

为判断氨苯枫－联磺甲氧苄啶对人工诱发实验猪卜氏肺孢子虫肺炎的确切疗效。进行了本次试验。将人工诱发卜氏肺孢子虫肺炎成功的１１头实验猪中的１０头接受氨苯枫－联磺甲氧苄啶的治疗,１头为对照。每天治疗猪每次投服氨苯枫２片,联磺甲氧苄啶２片,每天２次,连服１０天。结果实验猪于治疗后５天症状有所缓解,第１０天恢复健康;对照猪症状进一步恶化,于第３天死亡。结果说明此药物组合对卜氏肺孢子虫肺炎有较好的疗效。     

OSTEOCHONDROSIS IN THE LATERAL FEMORAL CONDYLES OF A HORSE

Osteochondrosis of the lateral femoral condyles was diagnosed radiographically in an 8-month-old, female Arabian horse, which had been presented with a hindlimb lameness. The diagnosis was confirmed by gross and microscopic pathology. The location of the lesions was considered unusual for osteochondrosis in the horse.     

STANDING MYELOGRAPHY IN THE HORSE USING A NONIONIC CONTRAST AGENT

Standing myelography in the horse has been previously described. In that study, metrizamide was used and significant complications were reported. In recent years, the introduction of less-toxic nonionic contrast media has reduced the incidence of complications. This study was undertaken to determine whether standing myelography using a nonionic contrast medium could provide a diagnostic study and be performed safely in the equine patient. Standing myelography was performed in eight horses. The contrast medium used was iohexol. In five horses a myelogram of diagnostic quality was achieved; in one horse contrast flowed only to the level of C6 and in two horses contrast medium did not reach the cervical subarachnoid space. Owing to the difficulty in achieving good flow of the contrast medium in some horses, this procedure may be of limited utility. However, if puncture of the lumbosacral subarachnoid space can be achieved easily and quickly, standing myelography may be a clinically useful procedure. It may be attempted in cases in which the economic value of the patient makes myelography under general anesthesia impractical. In patients presenting for evaluation of ataxia it may be possible to perform a standing myelogram at the time of CSF sample collection from the lumbosacral space.     

SCINTIGRAPHIC EVALUATION OF THE THORACIC SPINE IN THE ASYMPTOMATIC RIDING HORSE

Scintigraphic evaluation of the spinous processes of the equine spine has been done by subjective evaluation of radiotracer uptake in clinically abnormal horses. To determine the range of variation in asymptomatic riding horses, 33 normal horses were examined. Two 60 degrees oblique views of the thoracic and lumbar spine were evaluated subjectively, and a semi quantitative method based on standardized regions of interest in each spinous process in T10-L3 was also applied. A ratio between each spinous process and a reference area (Rib 15 or 16) was calculated. The effects of two different color displays and a smoothing filter were assessed. The results of the subjective evaluation was compared to the calculated ratios, and the associations between age, gender, weight, height, use and increased radiotracer uptake, and ratios were analyzed. No significant association was found between age, gender, weight, height, use and increased radiotracer uptake, or ratio. One or more areas of increased radiotracer uptake between T13 and T18 were common in the asymptomatic riding horse, which may have implications for the interpretation of clinical patients. The blue, green and red color display had a higher sensitivity for detecting increased radiotracer uptake compared to the continuous grayscale. The smoothing filter used in this study had no effect on the detection of areas with increased radiotracer uptake. The association between the results of the subjective evaluation and the semi quantitative method was apparent when analyzed in T13-17. To evaluate if the semi quantitative method can replace the subjective evaluation, studies on clinically affected horses are necessary.     

DENTIGEROUS CYST IN THE VENTRAL CONCHAL SINUS OF A HORSE

A 14-year-old Quarter Horse was presented for evaluation of a chronic, intermittent purulent discharge from the left nostril. A radioopaque mass and multiple, air-fluid interfaces in the paranasal sinuses were identified on survey radiographs. The mass was removed and identified as a dentigerous cyst. Substantiated reports of dentigerous cysts in the paranasal sinuses are rare.     

CONGENITAL ATRESIA OF THE PAROTID DUCT IN A HORSE

Congenital anomalies of the equine salivary glands and their ductal systems are rare. In man, parotid duct atresia is thought to be due to a congenital malformation of the first branchial arch. One horse with unilateral parotid salivary duct atresia is described. Imaging modalities available for accurate diagnosis, and treatment options, are reviewed.     

A COMPARISON OF NORMAL FELINE THORACIC RADIOGRAPHS MADE IN DORSAL VERSUS VENTRAL RECUMBENCY

Thoracic radiographs of 11 normal cats were made in dorsal (VD) and ventral (DV) recumbency with a vertically directed x-ray beam. These radiographs were compared subjectively and objectively with each other and with an additional pair of radiographs made with the cats in dorsal and ventral recumbency using a horizontally directed x-ray beam. Differences were found between VD and DV thoracic radiographs but they were minimal. In VD radiographs the caudal mediastinum and accessory lobe regïon of the lung were more clearly seen but cardiac shape varied somewhat. In DV radiographs, the appearance of the heart was more constant and caudal lobar pulmonary arteries more clearly seen. The results of this study indicated that both VD and DV radiographs are satisfactory for radiographic examination of the feline thorax     

HYPERTROPHIC OSTEOPATHY CHARACTERIZED BY NUCLEAR SCINTIGRAPHY IN A HORSE

A five year old American Saddlebred gelding was admitted to the University of Illinois Veterinary Medical Teaching Hospital with a history of multiple leg lameness, depression and intermittent fever for a duration of six months. Physical examination revealed the horse to be underweight, depressed and afebrile. No abnormalities were detected during auscultation of the heart and lungs. All limbs possessed multiple hard swellings of the distal long bones and digits. The horse walked with a stiff gait and was reluctant to trot. Nuclear scintigraphy of the distal limbs revealed multiple areas of focally increased uptake in all limbs. Radiographs of several sites on the distal limbs showed evidence of periosteal new bone production corresponding to the areas of abnormal uptake. The horse was euthanized and at necropsy chronic, multifocal, fibrous pericarditis and epicarditis were observed grossly. The left atrial myocardium contained areas of osseous metaplasia. Histological evaluation of the distal long bones revealed proliferative periosteal new bone formation consistent with a diagnosis of hypertrophic osteopathy.     

ALIPOMA OF THE EXTENSOR TENDON SHEATHS IN A HORSE

This report describes the identification and surgical removal of a lipoma from the extensor tendon sheaths of a horse. To the authors' knowledge, this is the first report of a lipoma of the extensor tendon sheaths of a horse. Ultrasonographic evaluation was crucial to patient management, providing information regarding the soft tissue mass characteristics, tumor margins and synovial involvement prior to surgical exploration. Surgical removal was performed and was curative.     

ULTRASONOGRAPHIC, GROSS, AND HISTOLOGIC EVALUATION OF A TENDINITIS DISEASE MODEL IN THE HORSE

Collagenase-induced lesions of the superficial digital flexor tendon were monitored using diagnostic ultrasound and subsequently compared with gross and microscopic findings. The postinjury sonograms demonstrated hypoechoic or anechoic areas corresponding to areas of hemorrhage and necrosis. The size of the lesion increased and the echogenicity decreased with increasing units of collagenase injected into the tendon. As postinjury time increased, echogenicity increased, which corresponded to fibrous-tissue invasion and collagen deposition. The extent of tendon injury produced correlated with the amount of collagenase injected into the tendon. Diagnostic ultrasound is useful in evaluating injury and healing in collagenase— induced tendinitis.     

IMAGING BASILAR SKULL FRACTURES IN THE HORSE: A REVIEW

Due to the complex nature of the anatomy of the equine head, superimposition of numerous structures, and poor soft tissue differentiation, radiography may be of limited value in the diagnosis of basilar skull fractures. However, in many horses radiographic changes such as soft tissue opacification of the guttural pouch region, irregular bone margination at the sphenoccipital line, attenuation of the nasopharynx, ventral displacement of the dorsal pharyngeal wall and the presence of irregularly shaped bone fragments in the region of the guttural pouches are suggestive of a fracture of the skull base. These findings in conjunction with physical examination findings and historical information may lead to a presumptive diagnosis of a fracture. When available and when the patient will accommodate the equipment, computed tomography may give a definitive diagnosis owing to its superior resolution and differentiation of soft tissue structures.     

TOTAL ANOMALOUS PULMONARY VENOUS CONNECTION IN A FOAL

An 8-day-old Arabian-Morgan cross colt underwent cardiac evaluation. The foal was tachycardic, tachypneic, exercise intolerant and had a loud right-sided heart murmur and cyanotic mucous membranes. Total anomalous pulmonary venous connection was diagnosed with echocardiography and confirmed at postmortem examination. Total anomalous pulmonary venous connection is a very rare congenital cardiac abnormality that has not been reported before in the horse.     

ENLARGING BILATERAL FEMORAL CONDYLAR BONE CYSTS WITHOUT SCINTIGRAPHIC UPTAKE IN A YEARLING FOAL

Bilateral subchondral bone cysts of the femoral condyles were diagnosed by conventional radiography in a 14 month old Appaloosa colt. Surgical debridement was performed, and over the next 18 months the appearance of the cysts was evaluated with radiography and bone scintigraphy. On the preoperative scintigrams, increased radiopharmaceutical uptake was associated with the cysts. Despite continued radiographic enlargement, the cysts did not demonstrate increased radiopharmaceutical uptake post-operatively.     

LATERAL COLLATERAL LIGAMENT AVULSION OF THE HUMERORADIAL JOINT IN A HORSE

This report describes traumatic avulsion of the lateral collateral ligament of the humeroradial joint in a horse. The history and diagnostic procedures are included with relevant radiographs and ultrasonographs. The poor prognosis associated with this injury is due to degenerative joint disease.