New developments in footrot control

The eradication policy for footrot in sheep adopted by the Western Australian Department of Agriculture has produced an overall decline in the number of properties with the disease. Our knowledge of the disease has improved substantially as a result of the research conducted at the Slabany Regional Veterinary Laboratory in recent years. Laboratory tests now sssist stock inspectors and veterinary officers to distinguish between different forms of footrot and to quarantine and eradicate accordingly. The recent discovery of more effective foot-bathing solutions by officers of the Victorian Department of Agriculture will greatly assist further eradication procedures. Western Australia\u27s sheep industry can now be optimistic that the level of footrot will remain low

Prevalence of footrot in Swedish slaughter lambs

<p>Abstract</p> <p>Background</p> <p>Footrot is a world-wide contagious disease in sheep and goats. It is an infection of the epidermis of the interdigital skin, and the germinal layers of the horn tissue of the feet. The first case of footrot in Swedish sheep was diagnosed in 2004. Due to difficulties in distinguishing benign footrot from early cases of virulent footrot and because there is no possibility for virulence testing of strains of <it>Dichelobacter nodosus </it>in Sweden, the diagnosis is based of the presence or absence of clinical signs of footrot in sheep flocks. Ever since the first diagnosed case the Swedish Animal Health Service has worked intensively to stop the spread of infection and control the disease at flock level. However, to continue this work effectively it is important to have knowledge about the distribution of the disease both nationally and regionally. Therefore, the aims of this study were to estimate the prevalence of footrot in Swedish lambs at abattoirs and to assess the geographical distribution of the disease.</p> <p>Methods</p> <p>A prevalence study on footrot in Swedish lambs was performed by visual examination of 2000 feet from 500 lambs submitted from six slaughter houses. Each foot was scored according to a 0 to 5 scoring system, where feet with score ≥2 were defined as having footrot. Moreover, samples from feet with footrot were examined for <it>Dichelobacter nodosus </it>by culture and PCR.</p> <p>Results</p> <p>The prevalence of footrot at the individual sheep level was 5.8%, and <it>Dichelobacter nodosus </it>was found by culture and PCR in 83% and 97% of the samples from feet with footrot, respectively. Some minor differences in geographical distribution of footrot were found in this study.</p> <p>Conclusions</p> <p>In a national context, the findings indicate that footrot is fairly common in Swedish slaughter lambs, and should be regarded seriously.</p

Cross-infection of virulent Dichelobacter nodosus between sheep and co-grazing cattle

AbstractDichelobacter nodosus is the main aetiological agent of ovine footrot and the bacterium has also been associated with interdigital dermatitis is cattle. The aim of this study was to investigate possible cross-infection of virulent D. nodosus between sheep and co-grazing cattle. Five farms, where sheep previously diagnosed with virulent D. nodosus were co-grazing with cattle for different periods of time, were included. The study sample consisted of 200 cows and 50 sheep. All cows were examined for the presence of interdigital dermatitis, and ten ewes, preferably with symptoms of footrot, had the footrot scores recorded. On each farm, the same ten ewes and ten cows were chosen for bacterial analyses. Swabs were analysed for D. nodosus by PCR and culturing. D. nodosus isolates were virulence-tested and assigned to serogroups by fimA variant determination. Biopsies were evaluated histopathologically and analysed by fluorescent in situ hybridization for D. nodosus, Treponema spp. and Fusobacterium necrophorum. D. nodosus defined as virulent by the gelatin gel test were isolated from 16 sheep from four farms and from five cows from two of the same farms. All five cows had interdigital dermatitis. Two of the cows stayed infected for at least eight months. By pulsed-field gel electrophoresis (PFGE), the isolates from the five cows were found to be genetically indistinguishable or closely related to isolates from sheep from the same farm. This indicates that cross-infection between sheep and cows have occurred

Foot rot and other foot diseases of goat and sheep in the semiarid region of northeastern Brazil

This paper reports the occurrence and epidemiology of outbreaks of foot rot and other foot diseases in goats and sheep in the semiarid region of Paraíba, northeastern Brazil. Four farms were inspected for the presence of foot lesion in sheep and goats and for environmental conditions, general hygiene, pastures, and disease control measures. The prevalence of foot lesions was 19.41% (170/876) in sheep and 17.99% (52/289) in goats, ranging between 5.77% and 33.85% in different farms. Foot rot was the most common disease, affecting 12.1% of the animals examined (141/1165), but with significantly higher (p<0.05) prevalence in sheep (13.69%) than in goats (7.27%). The frequency of malignant foot rot was also significantly lower (p<0.05) in goats (9.53%) than in the sheep (40.83%). On one farm, Dorper sheep showed significantly higher (p<0.05) prevalence of foot rot (17.5%) than Santa Inês sheep (6.79%), and the number of digits affected was also higher in the former. Dichelobacter nodosus and Fusobacterium necrophorum were isolated from cases of foot rot. White line disease was found in 3.95% of the animals, sole ulcers in 1.29%, foot abscess in 1.03% and hoof overgrowth in 0.5%. The high rainfall at the time of occurrence, grazing in wetlands, clay soils with poor drainage, presence of numerous stony grounds, closure of the flocks in pens at night, and introduction of affected animals were considered predisposing factors for the occurrence of foot diseases

Virulence of Bacteroides nodosus in ovine footrot

Virulence, in relation to ovine footrot, was examined in a review which emphasised the primary role of Bacteroides nodosus, an anaerobic strict parasite of ungulates. The association of this parasite with other bacteria in the footrot lesion resulted in complex interactions of host. parasite and environment. However, experimentation showed that the severity of the footrot lesion was associated principally with two different properties of B. nodosus: protease stability and surface translocation, the latter being a probable function of the pilus. The relationship between virulence, extracellular protease and translocation was elucidated in terms of function rather than structure. For example, the severity of footrot lesions was not related specifically to the electrophoretic mobility of protease isoenzymes or outer membrane proteins of B. nodosus. Although there were only two levels of protease stability, surface translocation, measured as either colony size or degree of cellular twitching, varied continuously between isolates. It was suggested that surface translocation was the basis for a continuous spectrum of virulence observed in ovine footrot. Nevertheless, protease stability was associated specifically with microbial penetration of the epidermal matrix of the hoof , hence justifying a classification of B. nodosus isolates into virulent (stable protease) and benign (unstable protease) strains. Although this classification was considered realistic, the complexity of ovine footrot was emphasised by evidence that twitching motility mediated the effects of both ambient temperature and the footrot microbial flora on the severity of all forms of the disease

New developments in footrot control

The eradication policy for footrot in sheep adopted by the Western Australian Department of Agriculture has produced an overall decline in the number of properties with the disease. Our knowledge of the disease has improved substantially as a result of the research conducted at the Slabany Regional Veterinary Laboratory in recent years. Laboratory tests now sssist stock inspectors and veterinary officers to distinguish between different forms of footrot and to quarantine and eradicate accordingly. The recent discovery of more effective foot-bathing solutions by officers of the Victorian Department of Agriculture will greatly assist further eradication procedures. Western Australia\u27s sheep industry can now be optimistic that the level of footrot will remain low