Development and validation of a specific radioimmunoassay for equine osteocalcin

This study describes for the first time the development and validation of a sensitive and specific radioimmunoassay (RIA) for equine osteocalcin (OC) quantification using purified equine OC as standard, tracer, and immunogen for antibody formation in rabbits. The assay allowed to measure equine serum OC levels with a sensitivity of 0.2 ng/mL. Immunoreactive serum OC values of clinically normal, different-aged horses ranged from 3.68 to 127.31 ng/mL. Intra- and inter-assay coefficients of variation (CV) were 6.2 and 8.2%, respectively. Serial equine serum sample dilutions were linear. The recovery of equine OC from equine serum samples ranged from 93.88 to 107.9%. There was a tight correlation between OC values measured with the equine-specific OC RIA and two commercially available bovine-specific OC RIA kits. However, highest serum OC values were obtained with the equine-specific OC RIA. In conclusion, our equine-specific OC RIA is sensitive, linear, accurate, precise, and reproducible. The assay allowed to quantify OC in equine serum samples and might, therefore, be used to monitor equine osteoblast activity associated with bone diseases, exercise, therapy forms or diet.     

Development and validation of a radioimmunoassay for thyrotropin in cattle.

In mammals, thyrotropin, or thyroid-stimulating hormone (TSH), assay is used for the diagnosis of primary hypothyroidism. Hypothyroidism is the most common type of thyroid disorder in cattle. The aim of this study was to develop and validate, under physiologic and pathologic conditions, a radioimmunoassay (RIA) for bovine TSH (bTSH). Double RIA was performed with purified bTSH and specific bovine antiserum. Laboratory validation included research of minimal detection limit, accuracy, and reproducibility. The physiologic validation included a thyrotropin-releasing hormone (TRH) challenge performed on euthyroid cows and a follow-up of bTSH concentration over a 24-hour period. Furthermore, bTSH concentration was assayed in a large population of healthy dairy and beef cows to define reference interval. The pathologic validation was made by assaying bTSH and thyroid hormones on healthy and goitrous newborn calves. The minimum detection limit (MDL) for bTSH assay was 1.3 microU/ml. The recovery was 101% to 106%. The intra- and interassay coefficients of variation (CVs) ranged from 5% to 11% and 11% to 15%, respectively. The RIA covered the whole range of physiologic bTSH values, as shown by bTSH values induced by TRH-challenge. A pulsatile secretion of bTSH was observed, accompanied by a diurnal variation with lower night values than day values. Reference intervals of bTSH ranged from 1.3 to 13.0 microU/ml for beef and dairy breeds. Finally, bTSH easily discriminated goitrous newborn calves from healthy ones, leading to the definition of a cutoff value of 35 microU/ml. The bTSH assay positively reacted to physiologic and pathologic conditions. The accuracy and precision of the RIA were satisfying.     

Nutritional tips for veterinarians

As a herd‐living, nonruminant, hindgut fermenting, primarily grazing herbivore the horse has evolved with a specialised gastrointestinal tract capable of utilising a wide range of plant species, which are hydrolysed and/or fermented to yield energy and nutrients for bodily processes. Domestication has resulted in the horse often being fed and managed to suit human requirements rather than their own, which can lead to digestive, behavioural and clinical issues. Appropriate nutrition not only reduces the risk of a nutritional component being a limiting factor to performance, but it also supports the maintenance of health and appropriate behaviour. A basic understanding of the digestive processes therefore can be very valuable when deciding how to feed horses optimally for both health and activity. This article provides a general overview of the gastrointestinal tract from a nutritional perspective and points out a few key practical areas where knowledge of feeding practices can be helpful for veterinarians.     

Continuing professional development for veterinarians

Continuing professional development for veterinarians is expected to commence in the year after graduation and continue until retirement. The World Organisation for Animal Health standard for veterinary services is based on principles of an ethical, organisational and technical nature, and a mix of regulation, self-regulation and quality assurance approaches are used. Few jurisdictions have made a minimum requirement of continuing professional development, measured in hours or units, mandatory in 2004, however, there is an increasing expectation of veterinarians to keep a personal record of their continuing professional development activities. Such records might assist in defending complaints about professional misconduct, and provide a basis for planning and monitoring personal professional growth. Continuing professional development can be obtained by a variety of means through structured and unstructured learning activities. The rapid advances in communication technologies and ready access to available electronic databases at the beginning of the 21st century is rapidly changing the way students learn in veterinary schools and how they will acquire continuing professional development during their careers. Universities, governments, professional associations and special interest groups all have roles to play in the delivery of continuing professional development to the veterinary profession and to ensure a structure is in place to monitor improvements in the delivery of quality veterinary services.