The species most commonly found are L. pomona, L. icterohemorrhagiae, L. grippotyphosa, L. hardjo and L. canicola . The most common species affecting cattle is L. pomona . The milk of lactating cows may become thick, yellow and blood-tinged. Abortion two to five weeks after infection is common, but most occur about the seventh month of gestation. Diagnosis is confirmed by a blood test or culturing the organism.
Vaccines are available for five of the leptospira species that affect cattle.
Vaccination should be done 30 to 60 days before replacement heifers are to be bred, followed by a yearly booster vaccination. IBR virus is normally thought of as the cause of respiratory disease of cattle. Abortion occurs about 20 to 45 days after infection. An intranasal vaccine is available that can be used on pregnant cows, if necessary. Since IBR is very common and some IBR vaccines are not recommended for use in pregnant cows, it is advisable that heifers be vaccinated or revaccinated 30 to 60 days before breeding.