Osteoarthritis in the cat: 1. how common is it and how easy to recognise?

PRACTICAL RELEVANCE: Osteoarthritis (OA) is very common, particularly in older cats, but its clinical significance has largely gone unrecognised until recently. As in other species, OA is often painful and appropriate treatment is required to improve the animal's quality of life. Most cases appear to be primary or idiopathic. It is important for the clinician to actively seek these cases in the practice population. CLINICAL CHALLENGES: The recognition of chronic arthritic pain is a major challenge since most cats will not exhibit lameness. The main features of feline OA are changes in behaviour and lifestyle, which develop gradually and which owners tend to interpret as simply being the effects of old age. A meaningful physical orthopaedic examination can be difficult to achieve. A lack of familiarity with feline joint radiographs, and the fact that major cartilage pathology can be present in the absence of any bony change, mean that radiographic identification of OA in the cat can also be problematic. CLIENT QUESTIONNAIRE: The recognition of chronic arthritic pain in the cat is based on owner questionnaires designed to elicit information about changes in mobility, activity levels, grooming habits and general demeanour. EVIDENCE BASE: Several publications now report on the significance of behavioural and lifestyle changes as indicators of chronic arthritic pain in the cat. However, there is not as yet a fully validated owner-based questionnaire for recognising chronic pain in the cat. Furthermore, the aetiopathogenesis of feline OA still requires detailed investigation. Such studies are likely to make a major contribution to comparative rheumatology, since feline OA, more so than the canine disease, shows many similarities with human OA.     

Musculoskeletal imaging in the cat: what's normal? What's abnormal?

PRACTICAL RELEVANCE: Despite the increasing availability of ultrasonography, computed tomography and magnetic resonance imaging (MRI), radiography remains the primary imaging modality for the assessment of feline musculoskeletal disease in practice. In many respects, having a more feline-focused approach to radiography will reward the clinician with better quality images and, hence, a greater likelihood of a correct diagnosis. CLINICAL CHALLENGES: Correct interpretation of radiographic films requires familiarity with some of the unique aspects of normal feline skeletal anatomy. For optimal patient management, the clinician also needs an appreciation of the distinct advantages of advanced imaging modalities in certain circumstances, in particular for head trauma patients. EQUIPMENT: When considering what equipment is most suitable for musculoskeletal imaging, the small size of our feline patients means that image resolution is of primary importance. Choosing an x-ray system (film-screen or digital) that offers more detail, and selecting ultrasound probes of a higher frequency than would be used on larger canine patients, will go some way to improving the diagnostic yield of any feline imaging study. If there is the option of referral for MRI, and a choice between high-field and low-field MRI systems for the feline patient, a high-field system will always provide more detail. AUDIENCE: This review, drawing on the author's experience and established imaging and anatomical principles, aims to assist general veterinary practitioners in their approach to feline musculoskeletal imaging. It provides an overview of the imaging choices and techniques for different regions of the body, and gives examples of normal anatomy that is peculiar to the cat.     

Where should the effort be put to reduce the Salmonella prevalence in the slaughtered swine carcass effectively?

Infection with Salmonella Typhimurium is seldom associated with clinical disease in pigs. However, control is important as the public is concerned about the human health impact. The producers, the abattoirs and the authorities are interested in implementing procedures to mitigate this risk. To evaluate the effect of different procedures, a stochastic risk model was developed to simulate the prevalence of Salmonella infection during the production process from the live pig on the farm, to the final carcass. This paper describes the model and findings of simulating different control scenarios. The variables with maximum effect on the Salmonella prevalence on the final carcass were (1) number of herds with a high prevalence of Salmonella, (2) singeing efficiency, (3) contamination and cross-contamination at degutting and (4) cross-contamination during handling. However, improvement of any single factor in isolation had a limited impact upon the level of contamination. The largest reduction was observed when several factors were improved concurrently.