IDENTIFICATION OF AN OSSICLE ASSOCIATED WITH THE PALMAR ASPECT OF THE CARPUS IN THE HORSE

An ossicle associated with the palmar aspect of the carpus is described in five horses. The size of the ossicle varied from 3 x 4 mm to approximately 12 x 10 mm. The ossicles were located at the junction of the proximal and distal rows of carpal bones, between the palmaromedial aspect of the fourth carpal bone and the ulnar carpal bone. In 3 horses they were bilateral, in one horse unilateral, and only one limb was examined in the remaining horse. In all horses it was an incidental finding and not regarded to be a pathologic entity.     

Comparative efficacy of three antibiotic products for the treatment and prevention of sub‐clinical mastitis during the dry period

Summary

The comparative efficacy of a product containing 500 mg benzathine cloxacillin (Orbenin D.C.), another product containing 100 mg nafcillin, 300 mg procaine benzylpenicillin and 100 mg dihydrostreptomycin (Nafpenzal D.C.) and a third product containing 250 mg cephalonium (Cepravin D. C.), in the elimination and prevention of mastitis due to gram‐positive microorganisms during the dry period was investigated in 1253 cows located in 14 herds in Israël.

Although more uniform results were observed after treatment with Nafpenzal D.C., differences were not found among the products with respect to the overall efficacy but differences among herds were rather large. The mean cure rate for Staphylococcus aureus quarter infections was 81.4 per cent. New S. aureus infections which occurred between drying off and post calving sampling time were found in 7.0 per cent of the quarters.

Dry period therapy reduced infection level with S. aureus from 13.5 per cent of quarters to 8.0 per cent. A similar proportional decrease was found in infection level due to non‐agalactiae Streptococcus quarter infections.     

Partial mandibular condylectomy and temporal bone resection for chronic,destructive, septic arthritis of the temporomandibular joint in a horse

Sepsis of the temporomandibular joint (TMJ) of the horse is rare. This case report describes the use of radiography, ultrasonography and computed tomography to diagnose sepsis of the TMJ in a 2‐year‐old Thoroughbred filly. The mandibular condyle and temporal bone were partially resected to successfully remove necrotic tissue within and surrounding the TMJ. Sepsis resolved and the horse returned to race training. Follow‐up computed tomography examination showed generation of a mandibular ‘pseudocondyle’ at 8 months post operatively.     

The use of computed tomography to assist orthopaedic surgery in 86 horses (2002–2010)

Imaging‐assisted orthopaedic surgery is becoming part of routine orthopaedic practice in horses and several techniques have been reported. However, there are no published reports describing the use of intraoperative computed tomography (CT) for surgical guidance and immediate post operative control in the horse. This use of CT in equine orthopaedics is currently limited because of the logistic problems associated with availability of CT scans in surgical theatres as well as concerns over radiation safety. The aim of this report was retrospectively to report CT assisted orthopaedic surgical cases in our practice through identifying the types of surgery where it was used, to list the technical problems that were encountered, to describe solutions to these, and to discuss the applications of the technique. All surgical procedures were performed with the assistance of a peripheral quantitative computed tomography (pQCT) scanner. CT assisted orthopaedic surgery in 86 patients during the study period. Reasons for CT included: 1) use of CT at the beginning of the surgical procedure to document the lesion and identify surgical landmarks (n = 75); 2) pre, intra‐ and post operative use of CT in comminuted fractures of the middle or proximal phalanx to guide and control internal fixation (n = 7); and 3) post operative use of CT to monitor the results of the surgical procedure (n = 4). Proper planning in both the draping steps and the use of polyvinyl splints to stabilise the limb allowed for movements of the gantry around the limb. The time required to obtain one slice was not dissimilar to the time that is necessary to take and process a single digital radiograph. The radiation dose with the pQCT described here is <0.5 µSv and its acquisition time should be balanced against radiation risks of conventional CT systems.     

COMPUTED TOMOGRAPHIC ANATOMY OF THE EQUINE TARSUS

The purpose of this study was to provide a detailed computed tomographic (CT) anatomic reference for the equine tarsus. CT examinations of the tarsal regions from four clinically and radiographically normal adult horses, which were euthanized for reasons not related to musculoskeletal disease, were included in the study. Limbs were removed at the level of midtibia, and 3-mm contiguous transverse CT images were obtained, starting at a level proximal to the tuber calcanei and continuing distally into the proximal metatarsus. Soft tissue and bone windows were used to image different anatomic features, including bones, joints, and various soft tissue components of the tarsus. Each transverse slice was compared with bone models and dissected specimens to assist in the accurate identification of specific structures. The results of the study consist of nine CT images of the equine tarsus. Each image incorporates labeled soft tissue and bone-window images, a directional compass indicating cranial (Cr) or dorsal (D) and lateral (L), and a reconstructed scout image indicating the level through which the transverse slice was made.     

Technical set‐up and radiation exposure for standing computed tomography of the equine head

The recent adaptation of human computed tomography (CT) machines to enable scanning of the equine head via standing sedation has revolutionised our ability to acquire images of this complex anatomical region. There are a small number of CT systems installed worldwide and it is to be expected that this will increase in the next few years; however, currently, there is no publication that describes the technical set‐up required to permit CT scanning of the equine head. This paper describes the technical set‐up, technique and exposures necessary to accomplish CT scanning of the horse under standing sedation to diagnose disorders of the equine head.