Hematuria and leptospiruria in a foal.

A Thoroughbred foal that was born after 305 days of gestation was referred 6 hours after birth. On initial examination, the foal was alert, but weak and unable to stand. Heart rate was 150 beats/min, respiratory rate was 48 breaths/min, and rectal temperature was 33 C. Leukocytosis was detected (26,000 WBC/microliters). Dysuria and passage of red urine was observed approximately 30 hours after admission. Urine collected by free catch had a 3+ reaction for blood on dipstick analysis. Examination of Warthin Starry-stained sections of allantochorion revealed organisms morphologically characteristic of leptospira spp along the chorion. Results of direct fluorescent antibody tests on section of placenta were positive for Leptospira spp. Direct fluorescent antibody testing identified leptospires in the urine of the foal. Sera from mare and foal were tested for antibodies against Leptospira spp by use of the microscopic agglutination test. High titers were identified in serum from the mare and foal.