An outbreak of bovine leptospirosis due to leptospira hardjo and leptospira pomona in a zero-grazing dairy herd in Kenya

Abstract

Leptospirosis is a febrile disease attributable to any of the serologically distinct members of the Leptospira inter-rogans and may present itself in a variety of clinical syndromes in animals'':-". It is transmitted mainly through contami¬nated feed and water by convalescent or reservoir hosts'", Routes of infection are mainly through the mucosal membranes of the conjuctiva, mouth, oesophagus, intestine, reproductive tract and broken skin'", This communication reports on an outbreak of leptospirosis due to serovars hardjo and pomona in zero-grazing unit. Twenty four out of 34 adult cattle fed on a fresh batch of hay bought from a differ¬ent supplier were affected. The affected animals had slightly increased respirat¬ory and pulse rates, decreased ruminal movements and fluctuating fever during which the temperatures were higher in the afternoon than in the morning. Recurrence of fever lasting 2-4 days was observed in some animals 8-12 days after subsiding of the initial fever. Eight milk¬ing cows had slack and flabby udder with thick and yellow milk from all the quar¬ters. Nine cows over 5 months pregnant aborted within 2-3 weeks after the onset of the disease, 6 retained fetal mem¬branes and three had stillbirths. Eighteen cows and a bull had photosensitization (bluish-red discoloration) on the post¬erior surface of the udder, the testicles and around the pastern joint of the hind limbs. There was some lameness in some cows especially of the hind limbs.