Borrelia burgdorferi infection in Wisconsin horses and cows.
Blood samples from Wisconsin horses and cows suspected of having clinical disease due to Borrelia burgdorferi infection were submitted by veterinary practitioners. All serum, milk, colostrum, and synovial samples were tested for B. burgdorferi antibodies by immunofluorescence. Whole blood, milk, colostrum, and synovial fluid samples were cultured for B. burgdorferi. Records were kept on the clinical signs of antibody-positive animals, date of sample, and location of the animal by county. Of the samples tested for antibodies 282/430 cow sera, 118/190 horse sera, 5/10 cow synovial fluids, 3/6 horse synovial fluids, 2/3 cow colostrums, 0/44 cow milk samples and 1 aborted fetus serum were antibody positive at a titer of 1:128 or greater. Of samples cultured 7/156 cow bloods, 2/35 horse bloods, 1/14 cow synovial fluids, 0/4 synovial fluids, 1/3 cow colostrums, 0/44 cow milk, and 2/10 cow urine samples were B. burgdorferi culture positive. For both cows and horses October and May were the two peak months for the number of antibody-positive samples. The most frequent clinical signs in antibody-positive horses and cows were lameness and swollen joints, but many also had stiffness, laminitis, abortions, and fevers. Not all antibody-positive animals showed clinical signs. These findings show that B. burgdorferi infection occurs in horses and cows and can cause clinical illness in some but not all animals. Infection in cows and horses occurs most frequently 1 month after the emergence of adult I. dammini. Because spirochetes could be isolated from blood, synovial fluid, colostrum, and urine, these animals could be important in providing an infected blood meal for ticks and bringing B. burgdorferi in direct contact with humans.
Burgess
E C
EC
School of Veterinary Medicine, University of Wisconsin, Madison 53706.
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D001898:Borrelia / Q000276:immunology; D001899:Borrelia Infections / Q000662:veterinary*; D002417:Cattle / Q000276:immunology; D002418:Cattle Diseases / Q000453:epidemiology*; D003710:Demography; D005260:Female; D006734:Horse Diseases / Q000453:epidemiology*; D006736:Horses / Q000276:immunology; D008297:Male; D014922:Wisconsin
D000907:Antibodies, Bacterial