Serological evidence of spirochaetal infections associated with digital dermatitis in dairy cattle

A potentially infectious aetiology for digital dermatitis in dairy cattle was investigated and centred on the possible involvement of spirochaetes. An enzyme-linked immunosorbent assay (ELISA) was developed to detect bovine anti-Borrelia burgdorferi (B31) and anti-Treponeme (USA bovine isolates) antibodies in the sera of cows; sera were further tested for antigen specificity by Western blotting. Compared to normal cows, those with digital dermatitis had a much higher seropositivity rate to B. burgdorferi and the treponemes. Significant correlations were shown between antibodies to B. burgdorferi and to Treponemes (P < 0.001), suggesting strong cross-reacting epitopes shared by these spirochaetes. In Western blotting of B. burgdorferi antigens, the main band detected by ELISA positive sera was the 41 kDa flagellar protein; lesser frequency of staining was seen with 34 (OspB), 39 and 55 kDa bands. For the USA treponeme antigens, ELISA positive sera gave reactions to the 34-kDa band and also bands at 41 and 55 kDa. Polyclonal antibodies to Treponema denticola and T. vincentii showed reactions with the bovine treponemes which were predominantly to the 34-kDa antigen. Monoclonal antibodies to B. burgdorferi flagella (41 kDa) antigen and OspA (31 kDa) did not detect any treponeme bands in Western blotting. The study has provided serological evidence that spirochaetes (which are related to human treponemes) may be involved in the pathogenesis of digital dermatitis.

The frequent detection of a treponeme in bovine digital dermatitis by immunocytochemistry and polymerase chain reaction

A study was carried out to determine whether spirochaetes are frequently associated with digital dermatitis in United Kingdom (UK) dairy cattle. Histopathological examination of lesions using a silver stain showed a large number of unidentified spirochaete-like organisms present in digital dermatitis hoof skin tissue in all examined biopsies. Immunocytochemical staining demonstrated that spirochaetes in skin lesions were identified by polyclonal antisera to Borrelia burgdorferi, Treponema denticola and Treponema vincentii (again all biopsies were positively stained), whereas monoclonal antibodies to B. burgdorferi and any Treponema pallidum did not stain any organisms in all biopsies. A PCR of 16S rRNA, previously shown to be specific for a new treponeme, was employed and produced positive results from 82.4% of digital dermatitis tissues. It is concluded that this spirochaete (or related spirochaetes), which is similar to human oral treponemes, is frequently associated with, and may be responsible for, pathological changes in digital dermatitis.

Proliferative osteitis of the femoral greater trochanter and humeral medial epicondyle as a cause of lameness in sows

Thirteen chronically lame female breeding pigs were examined clinically and post mortem. Of the eight sows with hindleg lameness, one showed detachment of the ischial tuberosity and a second showed detachment of the ischial tuberosity on the left and a mid-shaft femoral fracture on the right. Two showed no lesions apart from a change in the positional relationship between the femoral head and the greater trochanter, resulting in a lowering of the femoral head. In the remaining four sows an apparently unreported condition was seen, which produced a proliferative osteitis of the greater trochanter. All five animals lame in the forelimb showed varying degrees of proliferative osteitis of the medial epicondyle of the humerus. Advanced cases could be palpated in the live animal. It is proposed that proliferative osteitis may be a response, at the point of attachment of the muscle masses of the major limbs, to the trauma of over exertion.

Effect of premilking teat disinfection on mastitis incidence, total bacterial count, cell count and milk yield in three dairy herds

An iodophor teat disinfectant was applied before milking by dip or spray to 50 cows and 50 cows were left untreated in each of three commercial herds. The mean incidence of clinical mastitis was reduced by 57 per cent, the total bacterial count by 70 per cent and the count of thermoduric organisms by 32 per cent. These results were not statistically significant, except that one herd showed a significant decrease in total bacterial count. There was no effect on somatic cell count, milk production or milk iodine residues. Atmospheric iodine concentrations increased in the two herds which applied the treatment as a spray, but the levels attained were not likely to be detrimental to human health.

A simple treatment for heel abscesses and deeper foot infections in cattle

A simple technique for the treatment of deep navicular and pedal joint infections in cattle is described. Under regional or local anaesthesia, a hoof-knife is inserted into the full depth of the discharging sinus and a large drainage area is created. A wooden block is glued to the sound claw and parenteral antibiotics are administered for four to six days. Of 64 cows treated between March 1986 and June 1989, 55 (86 per cent) recovered. The causes of failure and comparisons with other treatments are discussed.

Digital dermatitis in dairy cattle

A condition of digital dermatitis causing lameness in a dairy herd is described. The lesion was a small circumscribed area of epidermal inflammation in the skin immediately above the coronet between the bulbs of the heel. Topical treatment, consisting of excoriation and application of a gentian violet and tetracycline aerosol spray, was effective. Although the high incidence and rapid onset of the condition suggested an infectious cause, no organism was isolated consistently.