Transmission is via urine of affected animals; the organism gains entry at mucous membranes, broken skin, bite wounds and through ingestion of infected material. The organism can remain viable for weeks in damp conditions, rodents and other mammals act as a reservoir of infection. The incubation period is 2-12 days, after which dogs become lethargic, pyrexic and anorexic. The disease often progresses with renal and hepatic involvement. The host-adapted serovar ''canicolar'' causes acute renal failure in puppies; a chronic uraemic syndrome may follow. Incidental infections with serovar ''icterohaemorrhagica'' or ''copenhagenii'' cause renal failure; ''L. icterohaemorrhagiae'' may also cause [[Pigmentation and Calcification - Pathology#Hepatic (Toxic) Icterus|hepatic jaundice]]. Serovar ''bratislava'' has been reported to cause abortion and infertility in dogs, which may be the maintenance host. | Transmission is via urine of affected animals; the organism gains entry at mucous membranes, broken skin, bite wounds and through ingestion of infected material. The organism can remain viable for weeks in damp conditions, rodents and other mammals act as a reservoir of infection. The incubation period is 2-12 days, after which dogs become lethargic, pyrexic and anorexic. The disease often progresses with renal and hepatic involvement. The host-adapted serovar ''canicolar'' causes acute renal failure in puppies; a chronic uraemic syndrome may follow. Incidental infections with serovar ''icterohaemorrhagica'' or ''copenhagenii'' cause renal failure; ''L. icterohaemorrhagiae'' may also cause [[Pigmentation and Calcification - Pathology#Hepatic (Toxic) Icterus|hepatic jaundice]]. Serovar ''bratislava'' has been reported to cause abortion and infertility in dogs, which may be the maintenance host. |