Assessment of irradiated socket healing in the rabbit's mandible: Experimental study.

As bone healing is altered after external radiation therapy, its evaluation is mandatory and lacks in clinical practice. The aim of the pilot study was to validate micro computed tomography (microCT) as a simple and reliable technique for assessing irradiated bone healing in the rabbit's mandible and compare with histologic findings. Nineteen rabbits (female New Zealand white) were used. The radiation protocol consisted of 5 sessions delivering 8.5 Gy each. MicroCT was performed at D0, D7, D14, D28 and D42 for the control group and D0, D28 and D42 for the irradiated group. A modified Perry's score was determined on histologic samples, and comparison between microCT and histological findings was performed. The main differences between irradiated and non-irradiated rabbits were observed at Day 28 and 42. There was a strong correlation between imaging and histologic findings. Radiation decreases bone quality and bone mineral density. As the correlation was strong between microCT and histologic findings, micro imaging could be considered as a simple and reliable technique to assess bone healing after radiation therapy and allows an easy comparison between samples, without invasive procedures. Great attention should be kept on the parameters and on the region of interest. The development of in-vivo microCT enlarges the perspectives of microCT use in experimental studies, avoiding invasive procedures, and preserving animal lives and well-being, and furthermore lead to clinical applications.

Comparative Assessment of the Accuracy of Cytological and Histologic Biopsies in the Diagnosis of Canine Bone Lesions.

BACKGROUND: Osteosarcoma (OSA) should be differentiated from other less frequent primary bone neoplasms, metastatic disease, and tumor-like lesions, as treatment and prognosis can vary accordingly. Hence, a preoperative histologic diagnosis is generally preferred. This requires collection of multiple biopsies under general anesthesia, with possible complications, including pathological fractures. Fine-needle aspiration cytology would allow an earlier diagnosis with a significant reduction of discomfort and morbidity. HYPOTHESIS/OBJECTIVES: The aim of this study was to compare the accuracy of cytological and histologic biopsies in the diagnosis of canine osteodestructive lesions. ANIMALS: Sixty-eight dogs with bone lesions. METHODS: Retrospective study. Accuracy was assessed by comparing the former diagnosis with the final histologic diagnosis on surgical or post-mortem samples or, in the case of non-neoplastic lesions, with follow-up information. RESULTS: The study included 50 primary malignant bone tumors (40 OSAs, 5 chondrosarcomas, 2 fibrosarcomas, and 3 poorly differentiated sarcomas), 6 carcinoma metastases, and 12 non-neoplastic lesions. Accuracy was 83% for cytology (sensitivity, 83.3%; specificity, 80%) and 82.1% for histology (sensitivity, 72.2%; specificity, 100%). Tumor type was correctly identified cytologically and histologically in 50 and 55.5% of cases, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: The accuracy of cytology was similar to histology, even in the determination of tumor type. In no case was a benign lesion diagnosed as malignant on cytology. This is the most important error to prevent, as treatment for malignant bone tumors includes aggressive surgery. Being a reliable diagnostic method, cytology should be further considered to aid decisions in the preoperative setting of canine bone lesions.

Skeletal problems in poultry: estimated annual cost and descriptions.

This introductory, review presentation is a prologue to four full-length symposium presentations. Estimates of the annual cost of skeletal problems in poultry and definitions of noninfectious skeletal diseases in poultry are the focus of this article. Losses due to skeletal problems in poultry are caused by an increase in mortality and the number of cull birds, increased condemnations from septicemia-toxemia, and more downgrading from the trimming of breasts and legs. Reduced feed conversion and rate of gain also occur. Estimated annual losses in the United States due to skeletal problems are $80 to $120 million in broilers, and $32 to $40 million in turkeys. Eleven skeletal problems in poultry are described, and synonyms, symptoms, and possible causes of each are presented. These diseases include long bone distortion, tibial dyschondroplasia, rickets, spondylolisthesis, degeneration of the femoral head, spraddled legs, chondrodystrophy, osteomyelitis and synovitis, Mycoplasma synoviae infection, viral arthritis, and footpad dermatitis.

Costs of veterinary services and vaccines/drugs used for prevention and treatment of diseases in 60 Tennessee cow-calf operations (1987-1988).

Four percent of the total cost of disease in 60 Tennessee cow-calf herds in 1987 to 1988 was attributable to veterinary services, and 2.3% was attributable to the purchase of drugs to treat sick animals. When producers spent money on therapeutic veterinary services, it was most often attributable to diseases of the reproductive system ($0.69/cow annually), especially dystocia ($0.51/cow annually). When drugs were used therapeutically, the most was spent on products to treat respiratory tract disease ($0.37/cow annually). The cost of preventive veterinary services accounted for 8.8% of the total cost of preventive actions. Pregnancy examinations (considered here as a preventive action) was the most costly preventive service ($0.62/cow annually). The cost of drugs and biologicals used to prevent disease accounted for 69.4% of the total cost of preventive actions, with drugs to prevent intestinal and external parasites being the most costly ($7.79/cow annually). These figures are based on cow-calf herds randomly selected by use of a 2-stage, stratified plan. Herds were visited once a month for 1 year. Results of this study support other work that showed that beef producers perceive veterinarians as primary sources of information on diagnosis and treatment of sick animals and on reproduction/breeding, but less knowledgeable or cost effective in the areas of animal/herd management, feed nutrition, and agribusiness/economics.

Ultrasound as a tool for assessment of bone quality in the horse.

A simple non-invasive method is described for calculating the transverse apparent velocity of sound of horse bone. This was achieved, both in vivo and at post mortem examination using the metacarpal bone and its covering soft tissue. On 34 post mortem specimens (ie, 68 limbs) from horses older than one year an average measurement of 2802 +/- 37 (1sd) m/sec was obtained. There were changes noted according to age and at different sites on the shaft of the metacarpus. The highest readings were obtained in the proximal shaft where the cortex was thickest. The velocity values gradually decreased towards the distal end where the cortex was thinner, particularly in animals less than 12 months old. The soft tissue component of the velocity measurement was uniform throughout the length of the metacarpus and effectively decreased the apparent velocity of the bone alone by about 170 m/sec (6 per cent). The shortest flight path of the ultrasound beam was found to be through the midcortical region of the metacarpal shaft. A good correlation was obtained between velocity of sound measurements and bone mass. Furthermore partial demineralisation of specimens from the mid-metacarpal region caused a considerable reduction in the apparent velocity of sound. In a series of young thoroughbreds (n = 52) measured in vivo the apparent velocity of sound increased from around 2650 m/sec at six months to approximately 2880 m/sec at three years.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of radiographic positioning for the diagnosis of navicular disease in the horse.

Three of the standard radiographic views of the navicular bone were assessed in normal horses and horses with navicular disease to determine the most effective radiographic positioning. Using the upright pedal view, a pastern angulation of 20 degrees from the vertical produced the optimum result when radiographs were taken using a grid. The best result using the high coronary view was obtained with an anode-film distance of 1 1000 mm, and a tube-head angle of 50 degrees from the vertical. When the special navicular view described by Morgan was examined, the most satisfactory projection was obtained using an anode-film distance of 900 mm, a tube-head angle of 55 degree and the primary beam centred between the bulbs of the heel, for the diagnosis of navicular disease, a combination of the upright pedal view and the special navicular view appears most effective.