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In this paper we pursue the development of a technique to predict which truckloads or pens of calves are at highest risk to FFP by building a series of multivariate models in which we incorporated some of the above mentioned risk factors measured at a feedlot over a period of three years. These predictive models were then used to examine the question of whether FFP acts as a truly contagious disease in the feedlot. If multivariate models containing only non-contagious factors could accurately predict where FFP would cluster, then perhaps only non-contagious factors work on particular feedlot pens or transport trucks to place calves in those groups at increased risk of developing FFP. If, however, models containing exclusively non-contagious factors were not effective at predicting where the disease clusters, this could mean that a "contagious factor"was missing from our models., American Association of Bovine Practitioners Proceedings of the Annual Conference, 1998

Disease outbreak investigations can be an important, challenging part of beef practice. They require one to develop, by planning and experience, a thorough investigative approach which can be used to identify patterns and distinguish between the normal and the abnormal. Epidemiology is a key tool, but careful observation and logical deduction are also important. If handled correctly, even the most complicated disease outbreak situations can become excellent practice builders for the bovine practitioner. We present the basic steps that we have found necessary to ensure success in an investigation of disease problems in the beef herd. We place emphasis in this particular presentation, though, on one of the main tasks of the investigation, which is to clearly define the problem as early as possible. This is because, to paraphrase some well-placed advice, a problem well-defined is three-quarters of the solution., American Association of Bovine Practitioners Proceedings of the Annual Conference, 1998

The recent introduction of computers to the feedlot industry for monitoring animal health has markedly improved the efficiency with which we can use epidemiology as a means for developing new management techniques to prevent disease. With the computer we can keep accurate health records which can be analyzed rapidly by the attending veterinarian on a regular basis. We describe the kind of system we find useful for recording data on a computer in the feedlot. We also describe how those data can be summarized to help develop an epidemiological approach to disease management in the feedlot, using respiratory disease and hemophilosis as specific examples. Our experience is based upon working in medium-sized feedlots with capacities of several thousand to 15,000 or more head., American Association of Bovine Practitioners Proceedings of the Annual Conference, 1991

How can you decide which vaccines to recommend to your feedlot clients? The purpose of this presentation is to develop a framework for the bovine practitioner for assessing the value of a commercial bacterin, toxoid, or vaccine by examining the scientific literature. A logical approach to reading this literature would help differentiate published trials that could help you in practice from useless or entirely misleading trials. The principles are also extremely useful for carrying out trials within feedlots in your own practice. To demonstrate, I will refer generally to bovine respiratory disease (BRD) vaccines, and more specifically to recent research examining the effectiveness of a particular commercial Haemophilus somnus bacterin. Determining the effectiveness of this bacterin could be difficult because the organism is associated with a variety of clinical diseases, referred to generally as hemophilosis,1 and it has been implicated as one of the potential initiators of the BRD complex.2,3 How do you decide whether to recommend the use of this bacterin, or any other vaccine, for the prevention of hemophilosis or BRD?, American Association of Bovine Practitioners Proceedings of the Annual Conference, 1991

Data collected from 197 replacement heifers in four beef cow herds in Saskatchewan were analyzed to determine the usefulness of pelvic area measurements as an on-farm test for predicting calving difficulty.The prevalence of calving difficulty in these herds ranged from 15-34%. Pelvic area measurements prior to the breeding season and at the time of pregnancy examination had poor positive predictive values and sensitivities in each herd. These findings were consistent whether the measurement used as a cut-off point to distinguish between a large and a small pelvic area was the lower 25th percentile, the mean, or the common standard. Standard pelvic area and calf birth weight ratios were not useful in estimating deliverable calf birth weight.Based on these results, pelvic area measurements prior to the breeding season and at the time of pregnancy examination are poor tests for predicting calving difficulty.

Anomalous development is a function of the genetic make-up of the fetus and the environment in which it develops. The cause of anomalous development may occasionally be obvious but more often is obscure, because of its multifactorial nature. Therefore a methodological approach is often required to define the etiology. In this paper we describe a methodological approach that first defines the incident, the genotype of the individuals involved, and the environment in which the fetus has developed. This procedure can be undertaken in a stepwise fashion and need not be followed through to the end if the etiology becomes obvious. This approach highlights the necessity to characterize the defects, to use ancillary tests, and to apply basic epidemiological methods.

Five feeding trials were performed on three ranches to determine if a distinctive, recurring, congenital anomaly in beef calves was associated with feeding clover or grass silage without supplementation to pregnant cows overwinter. The anomaly, termed congenital joint laxity and dwarfism, was characterized at birth by generalized joint laxity, disproportionate dwarfism, and occasionally, superior brachygnathia. The anomaly had been documented for several consecutive years on these ranches and affected 2-46% of the calf crop.Pregnant cows were divided randomly into feeding groups, and the number of abnormal calves in each group was tabulated. Supplementation of the overwinter grass/clover silage diet with hay (2.5-4.5 kg/head/day) and rolled barley (0.75-1.5 kg/head/day) eliminated the problem. Supplementation of grain, without hay, was not as effective. Varying the proportions of grass and clover in the silage, and the age of the silage, did not alter the teratogenic potency of silage. Vitamin D(3) supplementation did not reduce the risk of the condition. The definitive cause of congenital joint laxity and dwarfism was not determined.

The serious interest now being taken by the veterinary profession in implementing and promoting health management programs is very encouraging. Theodore Levitt has suggested that there is no such thing as a growth industry, and, " ...industries that assume themselves to be riding some automatic growth escalator invariably descend into stagnation. There are only companies organized and operated to create and capitalize on growth opportunities. The history of every dead and dying "growth" industry shows a self-deceiving cycle of bountiful expansion and undetected decay."1 We should not be surprised, therefore, that the "escalator" of traditional bovine medicine is moving downwards. A shrinking agricultural dollar, expanding veterinary schools, increasing competition for clients from non veterinary sources, changing market conditions, and increased costs of doing business have markedly reduced the growth potential of traditional veterinary medicine.2 This 1988 convention of the American Association of Bovine Practitioners, with its emphasis on health management programs and methods of improving how we do business, is a strong indication that we are preparing to create and capitalize on growth opportunities!, American Association of Bovine Practitioners Proceedings of the Annual Conference, 1988

In March 1985 the manager of the largest cow-calf operation in Prince George, British Columbia presented one of us (CSR) with a disproportionately dwarfed, dead, newborn calf. He stated that he was seeing a disconcerting number of these calves for the second consecutive year and that he would like to know what was causing them. The calves tended to have normal sized bodies but short legs; they tended to be weak at birth; when they could stand they did so on hyperextended pasterns and had trouble ambulating on extremely unstable joints (Figure 1). By the end of the calving season we had seen more than 35 of these calves, most of which were dead or unmarketable., American Association of Bovine Practitioners Proceedings of the Annual Conference, 1988

Antimicrobial drugs may be used to treat diarrheal illness in companion animals. It is important to monitor antimicrobial use to better understand trends and patterns in antimicrobial resistance. There is no monitoring of antimicrobial use in companion animals in Canada. To explore how the use of electronic medical records could contribute to the ongoing, systematic collection of antimicrobial use data in companion animals, anonymized electronic medical records were extracted from 12 participating companion animal practices and warehoused at the University of Calgary. We used the pre-diagnostic, clinical features of diarrhea as the case definition in this study. Using text-mining technologies, cases of diarrhea were described by each of the following variables: diagnostic laboratory tests performed, the etiological diagnosis and antimicrobial therapies. The ability of the text miner to accurately describe the cases for each of the variables was evaluated. It could not reliably classify cases in terms of diagnostic tests or etiological diagnosis; a manual review of a random sample of 500 diarrhea cases determined that 88/500 (17.6%) of the target cases underwent diagnostic testing of which 36/88 (40.9%) had an etiological diagnosis. Text mining, compared to a human reviewer, could accurately identify cases that had been treated with antimicrobials with high sensitivity (92%, 95% confidence interval, 88.1%-95.4%) and specificity (85%, 95% confidence interval, 80.2%-89.1%). Overall, 7400/15,928 (46.5%) of pets presenting with diarrhea were treated with antimicrobials. Some temporal trends and patterns of the antimicrobial use are described. The results from this study suggest that informatics and the electronic medical records could be useful for monitoring trends in antimicrobial use.