Hypothermia and depression precede death. Various compensatory signs relating to shock may be seen - including increased respiratory rate, increased heart rate and poor capillary refilling rate. Less acute cases develop a variety of signs including hyperaesthesia, injected mucous membranes with petechial and ecchymotic haemorrhages. The kidneys are badly injured which can lead to chronic renal failure. Jaundice is frequently seen and, if the liver is severely affected, bile output might cease causing very pale faeces.
Liver failure can result.
Sometimes intussusception can occur in association with inflammation of the intestinal tract and abortion or infertility can result if transplacental infection takes place. Vaccination can reduce the severity of the clinical course in infected animals but it does not prevent the carrier state - which presents a risk for humans. New vaccines are being developed which will cover a larger number of serovars, and which will produce high, protective antibody titres after only 2 weeks. Specific fluorescent antibody staining techniques have also been developed. Urine contains the highest concentration of organisms , but they can also be identified in blood and other fluids.