No abstract

RECENT decades have witnessed changes in the practice of veterinary medicine (Thrusfield 1998). In developed countries, the successful control of the major infectious diseases and the resultant intensification of livestock enterprises has produced a shift in interest towards complex, frequently noninfectious, diseases, and increasing emphasis is being placed on the health of herds rather than individual animals (Brand and others 1996). In contrast, in developing countries, the control of infectious diseases is still the major problem and progress needs to be made both in the measurement of disease frequencies, for example of trypanosomiasis in Africa and Asia, and in the implementation of control and/or eradication campaigns, for example for rinderpest (IAEA 1991). These changes have required the application of quantitative epidemiological procedures (Noordhuizen 1996), notably the use of rigorous sampling theory when conducting field surveys, and observational studies to identify the risk factors associated with multifactorial diseases in both farm practice and companion animal practice. Moreover, diagnostic tests applied either to individual animals, or to animal populations in eradication campaigns, can only be interpreted correctly when their validity and reliability has been assessed. Despite a long history in veterinary medicine, many diagnostic tests, particularly serological tests, have not been so assessed.The methods and statistical theory that underpin these quantitative procedures have been described by Martin and others (1987), Thrusfield (1997), and Noordhuizen and others ( 1997), and several computer programs have been designed to facilitate the necessary computations by veterinarians and physicians. These include suites of programs, such as EPI INFO (Dean and others 1995), PEPI (Gahlinger and Abramson 1995), EPISCOPE (Frankena and others 1990) and EPIZOO (Kouba 1997), and many programs for specific, individual analyses (The Epidemiology Monitor). However, these programs have limitations, especially for users who lack a grounding in analytical techniques. The package WIN EPISCOPE 2.0 has therefore been designed to combine the procedures that are commonly used in the design and analysis of epidemiological studies into an easy-to-understand form based on Microsoft Windows.The package provides the main computational procedures used in the design and analysis of simple field surveys, in control campaigns and observational studies, and in the assessment of diagnostic tests, and includes an introduction to basic mathematical modelling of infectious diseases. For each computation, comprehensive'Help' menus are provided which describe the techniques and list, with references, the formulae that are used. The package is an improved and expanded version of EPISCOPE for MS DOS (Frankena and others 1990) and of its first Microsoft Windows release, WIN EPISCOPE 1.0 (Ortega and others 1996).

The association in bitches between breed, size, neutering and docking, and acquired incompetence of the urethral sphincter mechanism was investigated. Observational studies were conducted on referred and first-opinion cases of hormonal urinary incontinence and on referred, confirmed cases of incompetence of the urethral sphincter mechanism. Large and giant breeds were at high risk, whereas small breeds were at low risk. Specific breeds at high risk were the old english sheep-dog, rottweiler, dobermann pinscher, weimaraner and Irish setter. The labrador retriever had a relatively low risk. There was also a positive association between docking and neutering, and the two conditions.

A five-year cohort study was conducted on bitches chosen by a sample of 233 randomly selected practising veterinary surgeons in the UK, to estimate the incidence of acquired urinary incontinence (AUI) in neutered and entire animals, and to investigate possible risk factors associated with neutering practices. Information was collected using questionnaires, and data on 809 bitches, of which 22 developed AUI, were obtained. The estimated incidence rates in neutered and entire animals were 0.0174 and 0.0022 per animal-year, respectively (95 per cent confidence intervals: 0.0110, 0.0275 and 0.0009, 0.0058, respectively). The relative risk, neutered vs entire, was 7.8 (95 per cent confidence interval: 2.6, 31.5). The attributable proportion(exposed) and population attributable proportion were 87.1 per cent and 63.1 per cent (95 per cent confidence intervals: 61.9 per cent, 95.6 per cent, and 28.3 percent, 88.5 per cent, respectively). An increased risk, significant at the conventional 5 per cent level, was not demonstrated in animals neutered before, vs after, first heat (relative risk: 3.9, 95 per cent confidence interval: 0.8, 10.4), although the result was significant at the 10 per cent level. Removal of the cervix was not shown to be a risk factor in neutered dogs.

BackgroundHuman brucellosis has been found to be prevalent in the urban areas of Kampala, the capital city of Uganda. A cross-sectional study was designed to generate precise information on the prevalence of brucellosis in cattle and risk factors for the disease in its urban and peri-urban dairy farming systems.ResultsThe adjusted herd prevalence of brucellosis was 6.5% (11/177, 95% CI: 3.6%-10.0%) and the adjusted individual animal prevalence was 5.0% (21/423, 95% CI: 2.7% - 9.3%) based on diagnosis using commercial kits of the competitive enzyme-linked immunosorbent assay (CELISA) for Brucella abortus antibodies. Mean within-herd prevalence was found to be 25.9% (95% CI: 9.7% - 53.1%) and brucellosis prevalence in an infected herd ranged from 9.1% to 50%. A risk factor could not be identified at the animal level but two risk factors were identified at the herd level: large herd size and history of abortion. The mean number of milking cows in a free-grazing herd (5.0) was significantly larger than a herd with a movement restricted (1.7, p < 0.001).ConclusionsVaccination should be targeted at commercial large-scale farms with free-grazing farming to control brucellosis in cattle in and around Kampala city.