A Survey on Leptospirosis in Horses of North Area of Iran

Background: leptospirosis is a global disease of all mammalian and is an important zoonosis. in horses, leptospirosis can cause considerable economic consequences, especially in mares, through abortions, stillbirth, infertility, perinatal deaths, and the birth of weak foals. the main clinical signs in horses are usually include weight and performance loss, reproductive complications and recurrent uveitis, however, subclinical leptospirosis and carrier status are much more common. in acute cases, fever, anorexia, icterus, anaemia, and petechial haemorrhaging of mucosae may occur, culminating in respiratory symptoms. it seems that north provinces of iran are having more favourable climate conditions for surviving the water-born diseases such as leptospirosis. objectives: during 2012 and 2021, a total of 853 blood samples from horses of north provinces of iran were delivered to the leptospira research laboratory for serological diagnosis. the aim of this study was to determine the current status of leptospirosis in horses of the north regions of iran based on leptospira research laboratory mat results.materials and methods: all blood samples were collected from the jugular vein and were transferred to the leptospira research laboratory of the faculty of veterinary medicine, university of tehran, in 10 ml evacuated glass tubes. serum was separated by centrifugation and stored in 1.5 ml eppendorf tubes at -20°c until using. microscopic agglutination test (mat) was performed on all of the serum samples, according to the standard methods of who using 5-7 days culture of live leptospira antigens. the seven leptospira interrogans serovars used were included australis, autumnalis, canicola, grippotyphosa, hardjo, icterohaemorrhagiae and pomona. two standard controls were included for each test as positive standard serum and negative standard serum. ten μl of the appropriate antigen was added to 10 μl of each diluted serum sample on a microscope slide. the microscope slide was placed in a petri-dish with moist paper to avoid evaporation, and incubated at 29c for 90 minutes. the slide was examined under dark-field microscope (olympus bx50), using a long working distance objective at x100 magnification.