R. Farina

Experimental infection in sheep with Leptospira interrogans serotype hardjo.

SUMMARY Twelve ewes (six pregnant) and two lambs were inoculated with Leptospira interrogans serotype hardjo, four lambs and one ram were kept as untreated controls. Pyrexia and antibody titres in all inoculated animals were consistent with infection. Leptospiraemia occurred in nine of the 14 inoculated animals. Clinical signs were so mild as to pass unnoticed under field conditions. No spread of infection to the controls was recorded. Two ewes aborted but no leptospires were demonstrated in organs of the aborted foetuses. Two ewes were found to be excreting leptospires in their urine on the 35th day post inoculation.

Experimental infection of sheep with Chlamydia psittaci.

Abstract Six sheep in the 33rd to 95th day of their first pregnancy were infected experimentally with Chlamyida psittaci isolated from a natural case of ovine abortion in Italy. Four received a single oral dose of 10 10 50% chick embryo lethal doses (CELD 50 ) and two were infected by intramuscular injection of 3×10 9 CELD 50 . Infection caused pyrexia in 5 of the 6 animals, one of which aborted 3 days after infection, when 98 days pregnant, and complement-fixing antibodies were detected in all 6 sheep within 10 days of infection. Chlamydial-associated placentitis caused abortion at 136 days of gestation in one case and was detected in two sheep which produced viable full-term lambs. Insufficient placental material was recovered from the two other animals which lambed at term for examination to be conclusive. The results demonstrate the pathogenic potential for sheep in mid-pregnancy of the Italian isolate of C. psittaci .