A Prosthetic Implant for the Equine Carpal Joint: Surgical Technique and Results

A prosthesis designed to partially replace the articular surfaces of the radial and third carpal bones was implanted bilaterally in 6 normal horses. The prosthesis consisted of a convex metal alloy component, and a concave ultra-high molecular weight polyethylene component, for implantation into the radial and third carpal bones, respectively. One horse underwent the soft tissue approach only to serve as a control. Effects on joint motion and pathologic changes were monitored over a 6-month period using clinical examination, synovial fluid analysis, electrogoniometry, high-speed cinematography, radiography, and gross and microscopic pathologic examination. Six months following implantation, all horses that received implants would trot, with slight to moderate lameness. Electrogoniometric and cinematographic evaluation of joint motion demonstrated a reduction in amplitude of the carpus in 4 horses receiving implants; however, in 2 horses, the reduction was less than, or equivalent to, that of the control horse. One horse that received the prosthesis was rideable, and was able to run with minimal lameness. Radiography, synovial fluid analysis, and gross and microscopic pathologic examination revealed varying degrees of synovitis and osteoarthritis. Biomechanical alterations of the middle carpal joint and release of wear particles from the prosthesis were considered to be major causes of these secondary changes. Changes in design of the prosthesis, intended to more accurately maintain normal joint biomechanics are proposed.     

Testing the concept of virally vectored immunosterilisation for the control of wild rabbit and fox populations in Australia

SUMMARY: Virally vectored immunosterilisation is a concept whereby a gene encoding an antigen from an animal's reproductive system is inserted into a virus and, during infection, stimulates the formation of antibodies to that antigen such that the animal is rendered infertile. There is good evidence that certain proteins from sperm or egg when introduced parenterally will induce infertility. This paper summarises the work of the Cooperative Research Centre for the Biological Control of Vertebrate Pest Populations and reviews progress toward the isolation of the genes for gamete antigens from rabbits and foxes and their introduction into suitable viral vectors as a means of control of these pests in Australia     

Microanatomy of the Canine Claw

Abstract— The histologic appearance of the canine claw was evaluated in twenty dogs of various breeds. Sagittal and horizontal cross sections of the claw were obtained, fixed, decalcified and stained with hematoxylin and eosin. Sections were evaluated and are described herein. Among notable findings were few to numerous intranuclear vacuoles found predominantly in the cells of the stratum spinosum, especially in the dorsal and ventral matrix. These vacuoles displaced the chromatin to the periphery. There was epidermal ridge formation in the angle of the dorsal fold. In several specimens there were clefts at the dermoepidermal junction present most commonly in the dorsal matrix. The previously reported lack of a granular layer in the epithelium forming the claw was confirmed. Résumé— L'aspect histologique de l'ongle du chien a étéétudié chez 20 chiens de races différentes. Des coupes horizontales et sagitales ont été faites, fixées, décalcifiées et colorées à l'hémalin-éosine. Parmi les observations les plus significatives on note de nombreuses vacuoles intranucléaires principalement dans les cellule de la couche épineuse et plus particulièrement au niveau dorsal et ventral de la matrice. Ces vacuoles déplacement la chromatine en périphérie. Il y avait des crêtes épidermíques au niveau du pli dorsal. Dans plusieurs specimens il existait des disjonction dermoépidermiques, principalement au niveu de la matrice dorsale. L'absence de couche granuleuse dans l'épithélium formant l'ongleprécédemment décrite a été confirmée. Zusammenfassung— Bei zwanzig Hunden verschiedener Rassen wurde der histologische Aufbau der Hundekralle untersucht. Es wurden sagittale und horizontale Schnitte angefertigt, fixiert, entkalkt und mit Hämatoxylin und Eosin gefärbt. Die Schnitte wurden ausgewertet und beschrieben. Beachtenswerte Befunde sind wenige bis zahlreiche intranukleäre Vakoulen, die vorwiegend in den Zellen des Stratum spinosum, speziell in denen der dorsalen und ventralen Matrix, gefunden wurden. Die Vakuolen drängten das Chromatin an die Peripherie. Im Winkel der dorsalen Falte war eine epidermale Kammbildung zu beobachten. Bei einigen Proben waren spalten in der dermoepidermalen Verbindung vorhanden, am häufigsten in der dorsalen Matrix. Das schon früher bekannte Fehlen einer granulären Schicht im Epithel, das die Kralle bildet, Wurde bestätigt. Resumen En este artículo se estudia la apariencia histológica de la uña canina en veinte perros de diferentes razas. En un principio se obtuvieron secciones sagitales y horizontales, luego se fijaron, decalcificaron, y tiñeron con hematosilina-eosina. Las secciones fueron evaluadas y se describiran a continuación. Entre un considerable número de hallazgos, se demostró la presencia dede un número de vacuolas intranucleares predominantemente en las células del estrato espinoso, y especialmente en la matríz dorsal y ventral. Estas vacuolas se encontraban desplazando la cromatina hacia la periferia de la célula. También se observó la presencia de la formación de una cresta epidérmica en el ángulo del pliegue dorsal. En algunos de los especimenes se vieron indentaciones a nivel de la frontera dermo-epidérmica, mas frecuentemente en la matriz dorsal. También se confirmo la ausencia de de capa granular en el epitelio de la uña.     

Canine granular cell tumour (myoblastoma): a report of four cases and review of the literature

Four cases of canine granular cell tumour (myoblastoma) were diagnosed at the Washington Animal Disease Diagnostic Laboratory between 1977 and 1981. Two of the tumours occurred in the tongue, one in the lip and one in the larynx. Three cell types were found in the tumours. Granular cells, with abundant periodic acid-Schiff (PAS)-positive cytoplasmic granules, were most numerous. Interstitial cells resembled fibroblasts and were often adjacent to collagen fibrils. Angulate body cells contained PAS-positive, ovoid cytoplasmic inclusions composed of microtubular subunits. Review of these and reported cases indicates no breed or sex predisposition for this rare tumour. The tongue is the most common site and all but one tumour have occurred in or adjacent to the oral cavity. There have been no reports of recurrence or metastasis of granular cell tumours except the recurrence of a disputed case in the subcutis of a dog.     

Evaluation of Cervical Spinal Fusion as a Treatment in the Equine "Wobbler" Syndrome

Cervical vertebral interbody fusion was performed on 30 horses affected with cervical vertebral malformation (CVM) or "wobbles" to assess the efficacy of the surgery in either preventing progression of or reversing the neurologic deficit induced by the syndrome. Evaluation of each horse prior to surgery included clinical, radiographic, neurologic, and laboratory examination. Subjects ranged from 3 months to 8 years of age, and included 22 males and 8 females of various breeds. Three normal horses were included as controls. The Cloward method of cervical fusion was used to achieve stabilization at the affected vertebral articulation. Horses were reexamined 3 months after surgery. Clinical improvement was seen in 90% (27 of 30) of the cases. Four horses were returned to training, which had been interrupted by onset of symptoms. Seven were returned to owners as breeding animals. Twelve horses were kept for long-term studies. Seven horses were sacrificed to examine the surgical site. In 6 of the 7 horses on which necropsy was performed, the most severe histologic lesion in the spinal cord could be predicted from lesions seen radiographically. The spinal cords of control animals were normal. Osseous fusion was dependent on the completeness of removal of disc fibrocartilage during surgery. We conclude that clinical improvement in some horses affected with CVM can be achieved by cervical fusion.     

IMAGING DIAGNOSIS: AZYGOUS CONTINUATION OF THE CAUDAL VENA CAVA WITH AND WITHOUT PORTOCAVAL SHUNTING

The CT angiographic features of azygous continuation of an interrupted caudal vena cava in dogs with and without portocaval shunting are described. Azygous continuation of a discontinuous caudal vena cava is usually an incidental finding, not associated with portosystemic shunting. Identification of an associated portosystemic shunt will determine the need for surgical intervention. CT angiography provides a means for making this distinction and details the course and size of the anomalous vessels. Focal widening of the caudal vena cava on a VD thoracic radiograph should raise suspicion for azygous vein distension.