Epizootic bovine abortion

From Cow
A stillborn calf which died as a result of Borrelia spp-induced epizootic abortion, transmitted by Ornithodorus coriaceus

Epizootic bovine abortions is a disease of cattle characterised by acute late-term abortion and is caused by the bacteria Borrelia spp and Myxobacteria spp.

Epizootic abortion is associated with beef cattle that graze in the mountainous regions of California, southern Oregon and western Nevada where the argasid tick Ornithodoros coriaceus is endemic[1].

In clinically affected cattle, fever, reduced milk production, lymphadenopathy, anorexia and joint pain have been reported associated with Borrelia spp infections. Erythematous lesions on the interdigital skin and hairless skin of the udder have also been described[2][3]. This spirochete-like organism is frequently found in abattoir-collected fetuses[4].

Foetal abortions appear to be triggered by vasculitis as a result of Borrelia spp colonisation of fetal lymph nodes and spleen. These foci frequently formed pyogranulomas[5].

A diagnosis is determined based on clinical signs supported by ELISA or PCR testing.

Affected cattle often respond to broad-spectrum antimicrobial therapy such as penicillins and tetracyclines.

Control of tick populations will minimise spread and outbreaks of this disease. Vaccines are not commercially used in cattle although they are available for other species.

References

  1. Teglas MB et al (2006) The geographic distribution of the putative agent of epizootic bovine abortion in the tick vector, Ornithodoros coriaceus. Vet Parasitol 140(3-4):327-333
  2. Lischer CJ et al (2000) Diagnosis of Lyme disease in two cows by the detection of Borrelia burgdorferi DNA. Vet Rec 146(17):497-499
  3. Burgess EC et al (1993) Borrelia burgdorferi infection in dairy cows, rodents, and birds from four Wisconsin dairy farms. Vet Microbiol 35(1-2):61-77
  4. Osebold JW et al (1987) Histopathologic changes in bovine fetuses after repeated reintroduction of a spirochete-like agent into pregnant heifers: association with epizootic bovine abortion. Am J Vet Res 48(4):627-633
  5. Kennedy PC et al (1983) Epizootic bovine abortion: histogenesis of the fetal lesions. Am J Vet Res 44(6):1040-1048