Counterintuitive increase in observed <i>Mycobacterium avium</i> subspecies paratuberculosis prevalence in sympatric rabbits following the introduction of paratuberculosis control measures in cattle

Paratuberculosis (Johne’s disease) is caused by the bacterium Mycobacterium avium subspecies paratuberculosis (Map). Achieving herd-level control of mycobacterial infection is notoriously difficult, despite widespread adoption of test-and-cull-based control strategies. The presence of infection in wildlife populations could be contributing to this difficulty. Rabbits are naturally infected with the same Map strain as cattle, and can excrete high levels in their faeces. The aim of this study is to determine if implementation of paratuberculosis control in cattle leads to a decline in Map infection levels in rabbits. An island-wide, test-and-cull-based paratuberculosis control programme was initiated on a Scottish island in 2008. In this study annual tests were obtained from 15 cattle farms, from 2008 to 2011, totalling 2609 tests. Rabbits (1564) were sampled from the 15 participating farms, from 2008 to 2011, and Map was detected by faecal culture. Map seroprevalence in cattle decreased from 16 to 7.2 per cent, while Map prevalence in rabbits increased from 10.3 to 20.3 per cent. Results indicate that efforts to control paratuberculosis in cattle do not reduce Map levels in sympatric rabbits. This adds to mounting evidence that if Map becomes established in wild rabbit populations, rabbits represent a persistent and widespread source of infection, potentially impeding livestock control strategies

Investigating the prevalence of Salmonella in dogs within the Midlands region of the United Kingdom

Background - The intimate relationship between dogs and their owners has the potential to increase the risk of human exposure to bacterial pathogens. Over the past 40 years, there have been several reports on transmission of salmonellae from dogs to humans. This study therefore aimed to determine the prevalence of Salmonella in the faeces of dogs from the Midlands region of the United Kingdom to assess exposure risk and potential for zoonotic transmission. Results - A total of 436 apparently healthy dogs without diarrhoea from households (n = 126), rescue centres (n = 96), boarding kennels (n = 43), retired greyhound kennels (n = 39) and a pet nutrition facility (n = 132) were investigated for Salmonella shedding. Faecal samples were processed by an enrichment culture based method. The faeces from one dog (0.23 %; 95 % confidence limit 0.006 %, 1.27 %) was positive for Salmonella. The species was S. enterica subspecies arizonae. Conclusion - This study showed that the prevalence of Salmonella from faeces from apparently healthy dogs from a variety of housing conditions is low; however, Salmonella shedding was still identified

Diagnosis and management of venereal campylobacteriosis in beef cattle

BACKGROUND: Bovine venereal campylobacteriosis is caused by Campylobacter fetus subsp. venerealis and its glycerine-tolerant variant Campylobacter fetus subsp. venerealis biovars intermedius. The disease can be economically important when present in cattle herds, causing poor reproductive performance, embryo mortality and abortion. Sensitive and specific diagnostic tests are required in the diagnosis of infection and to inform and monitor disease control. Current tests include bacterial culture and fluorescent antibody testing of preputial sheath washings and an enzyme-linked immunosorbent assay and an agglutination test on vaginal mucus, although the predictive values of these tests can be inadequate in field investigations. Artificial insemination is often considered as a simple control method for bovine venereal campylobacteriosis, but is impractical for many beef suckler herds where breeding takes place at pasture. Commercial vaccines are unavailable in the UK, while the efficacy of autogenous vaccines using a bacterial isolate from infected animals on a specific farm is at best unproven. Hence, for some infected herds, the development of an alternative control strategy based on segregation of potentially infected and uninfected animals in combination with culling or treatment would be desirable. This approach requires meticulous records and herd health management. CASE PRESENTATION: In this paper we highlight difficulties in diagnosing bovine venereal campylobacteriosis and demonstrate the benefits of good record keeping when investigating poor reproductive performance in a beef suckler herd and establishing a herd-specific approach to bio-containment of the infectious cause. CONCLUSIONS: Bovine venereal campylobacteriosis is an economically important disease that should be considered in investigations of suckler herd subfertility problems. Control of the disease based on segregation of potentially infected and uninfected animals in combination with extensive culling can be achieved without the use of artificial insemination or vaccination, but requires meticulous records and strict adherence to herd biosecurity practices