LOW-FIELD MAGNETIC RESONANCE IMAGING OF EARLY SUBCHONDRAL CYST-LIKE LESIONS IN INDUCED CRANIAL CRUCIATE LIGAMENT DEFICIENT DOGS

Six healthy adult male mongrel dogs underwent cranial cruciate ligament transection in the left stifle. Survey radiography of both stifles and low-field (0.064 T) MRI of the left stifle were performed preoperatively and at 2, 6, and 12 weeks postoperatively. Focal changes in signal intensity were seen with MRI in the subchondral bone of the medial tibial condyle at 2 and 6 weeks postoperatively. At 12 weeks postoperative, a cyst-like lesion was detected using MRI in the subchondral bone of the medial tibial condyle in 4 of 6 dogs and a less defined lesion at this site in the remaining 2 dogs. The cyst-like lesion was spherical in shape and showed typical characteristics of fluid with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images and high signal intensity on inversion recovery images. The lesion was seen in the subchondral bone of the caudal medial and/or middle region of the tibial plateau slightly cranial to the insertion of the caudal cruciate ligament. No subchondral cysts were seen in the tibia on radiographs. Histopathologically, the tibia was characterized by a loose myxomatous phase of early subchondral cyst formation.     

CORCTATION OF THE AORTA IN A DOG

This paper describes coarctation of the aorta with a large fusiform post-stenotic aneurysm in a 6 year old Great Dane. No clinical signs were attributable to the lesion, which was an incidental finding. The radiological and pathological features of aortic coarctation are described.     

LEUCOENCEPHALOMYELITIS OF GOAT KIDS

SUMMARY A leucoencephalomyelitis in 6 goat kids 2 to 5 months old is described. The disease was characterised by fever, ataxia, posterior paresis, circling and hyperaesthesia progressing to prostration. The neural lesion was confined to the white matter of the cerebellum and posterior brain stem in 4 kids, but in 2 others the cervical spinal cord was the main site affected. The lesion was characterised microscopically by dense perivascular cuffing with mononuclear cells, infiltration of the parenchyma with macrophages and a proliferation of glial cells and by a marked primary demyelination. In more advanced lesions, areas of the neurophil were replaced by a loose glial scar. There were associated pulmonary lesions of interstitial pneumonitis and hyperplasia of the peribronchiolar lymphoid tissue. Attempts to isolate an aetiological agent and to transmit the disease to young goat kids and lambs were unsuccessful. The disease has not been reported before in Australia but has distinct similarities to an infectious leucoencephalomyelitis of young goats which has been described in North America.     

OSTEOSARCOMA OF THE PATELLA WITH PULMONARY METASTASES IN A DOG

A 6-year-old neutered male Rottweiler was examined for a progressive right pelvic limb lameness. In radiographs of the right stifle, there was an osteolytic lesion with irregular new bone formation along the cranial aspect of the patella consistent with an aggressive bone lesion. In thoracic radiographs, there were multiple soft tissue nodular opacities throughout the lung fields, consistent with pulmonary metastases. Microscopically, fine needle aspirate samples from the right patella contained pleomorphic spindle cells with cytologic features of osteosarcoma. The presence of pulmonary metastases at the time of initial diagnosis in the dog described herein suggests that osteosarcoma of the patella has the potential for similar aggressive biologic behavior as that seen in dogs with appendicular osteosarcoma.     

RETROSPECTIVE REVIEW OF THE ULTRASONOGRAPHIC FEATURES OF ADRENAL LESIONS IN 21 FERRETS

Clinical signs and follow-up information were recorded. Histopathologic diagnoses were obtained for 25 adrenal glands in 21 ferrets. Adrenal lesions included ten adenocarcinomas, nine adenomas, one hyperplasia and one cortical cyst. Four adrenal glands (all right-sided) were diagnosed as unspecified adrenal tumors but lacked a definite histopathologic diagnosis (adenoma vs. adenocarcinoma) due to incomplete surgical resection and consequent small sample sizes. Bilateral adrenal lesions were identified in 4 ferrets (19%). Adrenal shape, size, echogenicity, laterality, and the presence of vascular invasion were evaluated with ultrasound. Size and shape were variable and not specific to lesion type. Both benign and malignant adrenal tumors (adenomas, adenocarcinomas) appeared most often as masses with increased thickness and a normal length (11/23), less frequently as larger masses with increased thickness and length (4/23) or as nodules focally deforming the normal adrenal shape (6/23). The only cortical cyst appeared as a nodule. Three adrenal glands had a normal size and shape and were diagnosed as adenomas (2) or hyperplasia (1). Therefore treatment may be warranted based solely on clinical signs if adrenal glands are ultrasonographically normal. Vascular invasion was not identified ultrasonographically. However, focal absence of periglandular fat resulting in contact of 8 adrenal glands with either caudal vena cava (6), aorta (1) or liver (1) identified ultrasonographically, correlated with incomplete surgical resectability (6/8) and histopathologic diagnoses of carcinoma (4/8) or unspecified tumors (4/8). Therefore, a focal absence of periglandular fat between the adrenal gland and the large vessels or liver, deviation or compression of the large vessels by the adrenal lesion may indicate malignancy. Adrenal tumors (benign and malignant) were often associated with a prominent uterus, uterine stump or prostate with or without prostatic cysts.     

ZAMIA PALM (MACROZAMIA REIDLEI) POISONING OF SHEEP

Sheep mortalities caused by the ingestion of leaves of the zamia palm (Macrozamia reidlei) were recorded from 6 properties in Western Australia from 1966 to 1971. Deaths occurred in sheep less than 2 years of age and involved from 2 to 9% of the flock. The primary lesion was acute hepatic necrosis, neurological effects were not recorded. The condition was reproduced experimentally when crushed kernel, mascerated leaf or leaf extract was administered by stomach tube.     

A XERORADIOGRAPHIC STUDY OF OSTEOCHONDROSIS IN THE METACARPOPHALANGEAL REGION OF TWO FOALS

Using xeroradiographic techniques, both metacarpophalangeal regions of six quarter horse foals were radiographed at 1 day of age and at 2-week intervals until they were 6 weeks old, and then at 4-week intervals until they were 12 months old. Lateromedial and dorsopalmar xeroradiographs of each metacarpophalangeal region were made per examination; dorsomedial-palmarolateral projections of the left metacarpophalangeal joint of foal 6 were also made. The foals were weighed and measured at the withers immediately prior to each examination. Representative xeroradiographs were selected to demonstrate progression of the osteochondrosis (OCH) lesions in two of these foals. Radiographic evidence of osteochondrosis in the metacarpophalangeal region was first detected at 10 weeks and followed through 12 months of age. In one foal the lesions were bilaterally symmetric and involved the dorsoproximal aspect of the sagittal ridge of metacarpal 3; in the other, the left medial proximal sesamoid bone was affected. One of the sagittal ridge lesions progressed to osteochondritis dissecans by 26 weeks; the other sagittal ridge lesion and that of the sesamoid bone healed spontaneously, but residual radiographic evidence of the disease persisted throughout the study in both foals.     

山东省潍坊地区肉鸡球虫的抗药性调查

应用石歧杂肉仔鸡,检测了采自我国山东潍坊的５种艾美耳球虫对６种常用抗球虫药的敏感性。根据最适抗球虫活性百分率、相对卵囊产量和病变记分减少率３项指标综合判定,山东潍坊地区的柔嫩艾美耳球虫,堆型艾美耳球虫,巨型艾美耳球虫、丰氏菌美耳球虫和缓艾美耳球虫的５个混合种对盐霉素Ｓａｌｉｎｏｍｙｃｉｎ、拉水 攻素Ｌａｓａｌｏｃｉｄ、莫能霉素Ｍｏｎｅｎｓｉｎ、马杜拉霉素Ｍａｄｕｒａｍｉｃｉｎ和常山酮Ｈａｌｏｆｕｇ     

ACCURACY OF DIAGNOSTIC ULTRASOUND FOR DETECTION OF CYSTIC LESIONS: DETERMINATION USING RECEIVER OPERATING CHARACTERISTIC CURVE ANALYSIS OF FINDINGS IN PHANTOM STUDIES

Anechoic, spherical cystic lesions are important findings on ultrasound examination. In polycystic renal disease of cats, they may be the only ultrasonographic sign of disease. This study assesses the accuracy of ultrasound, as used in a veterinary setting, for the detection of cysts. Using a spherical lesion ultrasound imaging phantom and 7.5- to 8-MHz linear array transducers, images of cysts of 2- and 4-mm diameter were created at various imaging depths from 0 to 6 cm. These were digitized and given to a panel of readers for interpretation. Area under receiver operating characteristic curves were used to evaluate test accuracy. It was shown that test accuracy was different at different imaging depths and differed with machines of differing price category. It is suggested that when setting standards for quality control in ultrasound, criteria used might be better related to imaging outcome studies rather than to aspects of machine specification.     

CONTRAST RADIOGRAPHY OF THE LOWER URINARY TRACT IN THE MANAGEMENT OF OBSRUCTIVE UROLITHIASIS IN SMALL RUMINANTS AND SWINE

Contrast radiographic visualization of the small ruminant and porcine lower urinary tract is an infrequently used modality for the evaluation and management of obstructive urolithiasis. The administration of contrast medium through a tube cystostomy catheter used to divert urine flow until the resolution of the obstruction may provide an easy method to evaluate the status of the urethral obstruction. Contrast fluoroscopy is utilized to monitor and visualize therapeutic flushing of the urethra. A review of 26 patients seen at the Veterinary Medical Teaching Hospital suggested that among the radiographic techniques used, positive contrast normograde cystourethrography through the tube cystostomy catheter allowed the best visualization of the lower urinary tract structures and enabled assessment of the resolution of the obstructive lesion.     

CONTRAST ENHANCED SONOGRAPHIC ASSESSMENT OF FEEDING VESSELS AS A DISCRIMINATOR BETWEEN MALIGNANT VS. BENIGN FOCAL SPLENIC LESIONS

Contrast‐enhanced sonography was conducted in 17 confirmed focal splenic lesions (five malignant, 12 benign). Relative echogenicity changes were used for subjective interpretation of lesion perfusion. A rapid influx of contrast agent, resulting in an increased relative echogenicity of the lesion, followed by a rapid clearance of contrast agent was referred to as early washin/early washout. There were 6/12 benign, and 3/5 malignant lesions characterized by early washin/early washout. Therefore, sensitivity, specificity, and accuracy for this parameter in differentiating malignant from benign lesions was 60%, 50%, and 53%, respectively. There were 2/12 benign, and 2/5 malignant lesions with persistent hypoperfusion throughout all phases. Therefore, sensitivity, specificity, and accuracy for malignancy using this criterion were 40%, 83%, and 71%, respectively. However, none of the benign and all malignant lesions were characterized by tortuous and persistently visible feeding vessels. This suggests that interpretation of splenic lesions cannot be performed accurately on the basis of echogenicity or persistent hypoperfusion, but that assessment of vascular tortuosity may be helpful in discriminating between a malignant vs. benign focal splenic lesion.     

IMAGING DIAGNOSIS—NUCLEAR SCINTIGRAPHIC,RADIOLOGICAL, AND PATHOLOGIC CHARACTERISTICS OF METASTATIC PILOMATRICOMA IN A DOG

A 6‐year‐old castrated Goldendoodle dog was presented for left‐sided lameness of 3 weeks’ duration. Focal, moderate to marked increased ^99mTc‐methylene diphosphonate (^99mTc‐MDP) uptake was detected in the right caudal lung lobe, caudal angle of the left scapula, and the distal aspect of the left femur with whole body bone phase scintigraphy. Radiographs identified a well‐circumscribed, oval‐shaped soft tissue opaque mass in the right caudal lung lobe; a suspect oval‐shaped osteolytic lesion in the proximal third of the left scapula; and an osteolytic lesion in the distal aspect of the left femur. Metastatic pilomatricoma was confirmed histologically at all three sites.     

Accuracy of the withdrawal reflex for localization of the site of cervical disk herniation in dogs: 35 cases (2004-2007)

OBJECTIVE: To evaluate the accuracy of neurologic examination versus magnetic resonance imaging (MRI) in localization of cervical disk herniation and evaluate the usefulness of withdrawal reflex testing in dogs. DESIGN: Retrospective case series. ANIMALS: 35 client-owned dogs with a single-level cervical disk herniation as determined via MRI. PROCEDURES: 1 of 2 board-certified neurologists performed a complete neurologic examination in each dog. Clinical signs of a cervical lesion included evidence of neck pain and tetraparesis. The withdrawal reflex was used for neuroanatomic localization (C1-C5 or C6-T2). Agreement between results of neurologic and MRI examinations was determined. RESULTS: Agreement between neurologic and MRI diagnoses was 65.8%. In 11 dogs in which the lesion was clinically localized to the C6-T2 segment on the basis of a decreased withdrawal reflex in the forelimbs, MRI revealed an isolated C1-C5 disk lesion. In 1 dog, in which the lesion was suspected to be at the C1-C5 level, MRI revealed a C6-T2 lesion. Cranial cervical lesions were significantly associated with an incorrect neurologic diagnosis regarding site of the lesion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the withdrawal reflex in dogs with cervical disk herniation is not reliable for determining the affected site and that a decreased withdrawal reflex does not always indicate a lesion from C6 to T2.     

EVALUATION OF DIFFERENT COMPUTED TOMOGRAPHY TECHNIQUES AND MYELOGRAPHY FOR THE DIAGNOSIS OF ACUTE CANINE MYELOPATHY

Forty‐six dogs with either cervical (C1–C5 or C6–T2) or thoracolumbar (T3–L3) acute myelopathy underwent prospective conventional computed tomography (CT), angiographic CT, myelography, and CT myelography. Findings were confirmed at either surgery or necropsy. Seventy‐eight percent of lesions were extradural, 11% were extradural with an intramedullary abnormality, 7% were intramedullary, 2% were intradural–extramedullary, and 2% had nerve root compression without spinal cord compression. Intervertebral disc herniation was the most frequent abnormality regardless of signalment or neurolocalization. Twenty‐one of 23 Hansen type I disc extrusions but none of the Hansen type II disc protrusions were mineralized. Two chondrodystrophic dogs had acute myelopathy attributable to extradural hemorrhage and subarachnoid cyst. CT myelography had the highest interobserver agreement, was the most sensitive technique for identification of compression, demonstrating lesions in 8% of dogs interpreted as normal from myelography and enabling localization and lateralization in 8% of lesions incompletely localized on myelography due to concurrent spinal cord swelling. None of the imaging techniques evaluated permitted definitive diagnosis of spinal cord infarction or meningomyelitis but myelography and CT myelography did rule out a surgical lesion in those cases. While conventional CT was adequate for the diagnosis and localization of mineralized Hansen type I disc extrusions in chondrodystrophic breeds, if no lesion was identified, plegia was present due to concurrent extradural compression and spinal cord swelling, or the dog was nonchondrodystrophic, CT myelography was often necessary for correct diagnosis.     

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.     

OSTEOSARCOMA IN THE MIDDIAPHYSIS OF THE RADIUS IN THE DOG

This case report describes the radiographic/clinical progression of a lesion in the middiaphysis of the radius in a dog. The lesion initially looked benign but progressed and eventually was diagnosed as an anaplastic osteosarcoma.     

Use of mucosal grafts and temporary tube implants for treatment of teat sinus mucosal injuries

A mucosal lesion was created in the center of each test sinus of 6 mature, healthy, nonlactating Holstein cows by resecting a circumferential band of mucosa. Each lesion was then treated by implantation of strip grafts of autogenous oral mucosa, temporary silastic tube implant, or a combination of strip grafts and temporary silastic tube implant. All teats were evaluated for patency 6 weeks after treatment, and tube implants were removed through a second thelotomy incision. All teats were reevaluated for gross and radiographic patency 12 weeks after treatment, and teats were collected for histologic evaluation of lesions. All 4 teats treated with grafts only were obstructed at 6 and 12 weeks after treatment. Incomplete coverage of the lesion with mucosa was observed in all 4 teats. The major source of obstruction was proliferation of epithelium and keratin into the lumen. All 8 teats treated with temporary silastic tube implants alone were patent at 6 weeks after treatment, but were obstructed at 12 weeks after treatment. Foci of mucosa at the lesion site were detected in only 2 of the 8 teats. Obstruction resulted from proliferation of granulation tissue into the lumen. All 12 teats treated with grafts and a temporary tube implant were patent at 6 weeks after treatment and 11 of 12 were patent at 12 weeks after treatment, although marked luminal narrowing was evident in 9 of 11 teats. Partial to complete coverage of the lesion with mucosa was seen in all teats. Proliferative granulation tissue, epithelium, and keratin contributed to luminal narrowing in 10 of 11 patent teats. Bacteriologic culture of quarters from 6 of the 11 teats patent at the final evaluation yielded pathogens.     

THE DURATION OF THE RESPONSE OF CATTLE TO INOCULATION WITH ATYPICAL MYCOBACTERIA

SUMMARY Each of 4 strains of atypical mycobacteria was inoculated into 2 cattle and the responses of the cattle were studied over the following 52 weeks. Each strain was injected subcutaneously into one animal and into a mesenteric lymph node of another. Within 7 days palpable lesions were produced at the sites of subcutaneous inoculation in response to all the strains. After intervals varying from 3 to 26 weeks, lesions due to 3 of the strains were no longer palpable. The lesion produced in response to the fourth strain, a non-agglutinable serotype of Mycobacterium intracellulare, was still palpable at necropsy, 52 weeks post-inoculation (PI). Of the 8 cattle inoculated with mycobacteria, the latter was the only animal that had a lesion with features consistent with a mycobacterial infection and from which mycobacteria were isolated. The inoculated cattle and 4 uninoculated control cattle were turberculin tested on 8 occasions during the post-inoculation period. Bovine purified protein derivative (PPD), avian PPD and PPD tuberculins prepared from each of the atypical mycobacteria were used. In inoculated cattle, sensitivity to both avian and bovine PPD was short lived, significant levels not persisting in any animal beyond 16 weeks PI. From the results of intradermal tests on the control cattle, a 95% confidence interval for their response to any of the 6 tuberculins used, was found to be ±1.36mm. On this basis all inoculated cattle developed sensitivity to the homologous tuberculin. The animal with mycobacterial granuloma at the subcutaneous inoculation site at necropsy had never developed significant levels of sensitivity to bovine PPD, had not shown significant levels of avian sensitivity after week 16 PI nor had it shown homologous sensitivity after week 22 PI. In all animals the level of sensitivity to bovine PPD decreased between successive tests. This fact could be used to clarify the status of a reactor if non-specific bovine sensitivity was suspected. Alternatively, the comparative intradermal tuberculin test using both bovine and avian PPD may be employed.     

ULTRASONOGRAPHIC EVALUATION OF EQUINE TENDONS: A QUANTITATIVE IN VITRO STUDY OF THE EFFECTS OF AMPLIFIER GAIN LEVEL, TRANSDUCER-TILT, AND TRANSDUCER-DISPLACEMENT

The objective of the in vitro experiments described in this paper was to quantify the effects of some instrumental variables on the quantitative evaluation, by means of first-order gray-level statistics, of ultrasonographic images of equine tendons. The experiments were done on three isolated equine superficial digital flexor tendons that were mounted in a frame and submerged in a waterbath. Sections with either normal tendon tissue, an acute lesion, or a chronic scar, were selected. In these sections, the following experiments were done: 1) a gradual increase of total amplifier gain output subdivided in 12 equal steps; 2) a transducer tilt plus or minus 3 degrees from perpendicular, with steps of 1 degree; and 3) a transducer displacement along, and perpendicular to, the tendon long axis, with 16 steps of 0.25 mm each. Transverse ultrasonographic images were collected, and in the regions of interest (ROI) first-order gray-level statistics were calculated to quantify the effects of each experiment. Some important observations were: 1) the total amplifier gain output has a substantial influence on the ultrasonographic image; for example, in the case of an acute lesion, a low gain setting results in an almost completely black image; whereas, with higher gain settings, a marked "filling in" effect on the lesion can be observed; 2) the relative effects of the tilting of the transducer are substantial in normal tendon tissue (18%) and chronic scar (12%); whereas, in the event of an acute lesion, the effects on the mean gray level are dramatic (40%); and 3) the relative effects of displacement of the transducer are small in normal tendon tissue, but on the other hand, the mean gray-level changes 7% in chronic scar, and even 20% in an acute lesion. In general, slight variations in scanner settings and transducer handling can have considerable effects on the gray levels of the ultrasonographic image. Furthermore, there is a strong indication that this quantitative method, as far as based exclusively on the first-order gray-level statistics, may be not discriminative enough to accurately assess the integrity of the tendon. Therefore, the value of a quantitative evaluation of the first-order gray-level statistics for the assessment of the integrity of the equine tendon is questionable.