General information
Leptospira are gram-negative bacteria and zoonotic agents which belong to the spirochete group. They are very thin, flexible, spiral bacteria with a hook-shaped end. Leptospira can actively move by twisting. Within the genus Leptospira interrogans sensu lato, there are various pathogenic and saprophytic species which cannot be differentiated morphologically, but only serologically or genetically. Since 1989, more than 250 serovars have been described that are currently classified in 24 serogroups.
Transmission of pathogens occurs directly through the urine or blood of infected animals or indirectly through inanimate vectors such as contaminated water, feed and sleeping places or living vectors like rodents. Leptospira best survive in a humid environment at temperatures of 0 – 25 °C.
Clinically, leptospirosis in dogs is initially manifested by anorexia, vomiting, dehydration and fever. Later, animals are apathetic and often show difficulty breathing. The mucous membranes are icteric, anaemia with haemoglobinuria appears and in some cases, as a complication, disseminated intravascular coagulation (DIC). Toxic degradation products lead to haemorrhagic diathesis and necroses. As a result, acute nephritis with azotaemia can arise. In some cases, hepatitis may also occur, which often has a highly acute course. Leptospira are fetotrophic.