Leptospirosis

Leptospirosis is a widespread problem in the South,
especially in unvaccinated herds. It causes repeat breeders,
low-grade uterine infections, abortions, mastitis and occasionally
systemic infection. Of the five or more strains of
the organism, the three most common causing problems in
cattle are Leptospira pomona, Leptospira hardjo and
Leptospira grippotyphosa.
Leptospirosis can build up unrecognized in a herd.
Closely confined cattle are particularly susceptible.
Droplets of urine from infected cows can infect normal
cows after contact with the eye or mucous membranes of
the nose or mouth. The disease infects more cattle each day,
preventing cows from settling and lengthening their calving
intervals.
  To prevent leptospirosis:
- Vaccinate cattle with bacterins containing three or
   five serotypes every six months;
- Drain stagnant bodies of water; and
- Eliminate rodents, especially rats, from any barns or
   sheds where cattle congregate.