Leptospirosis is caused by a spirochaete (spiral, or corkscrew-shaped) bacterium called Leptospiraspp. There are five major types of disease causing strains Icterohaemorrhagiae, Canicola, Pomona, Grippotyphosa, and Bratislava. Other, less common infectious strains are also there.
This is a zoonotic disease meaning that it can be transmitted to humans and other animals, therefore all care must be taken when handling the dog.
Spirochetes are bacteria which infiltrate the system by burrowing into the skin. Leptospires spread throughout the entire body, reproducing in the liver, kidneys, central nervous system, eyes, and reproductive system. Soon after initial infection, fever and bacterial infection of the blood develop, but these symptoms soon resolve with the reactive increase of antibodies, which clear the spirochetes from most of the system. Even then, Leptospira spirochetes can remain in the kidneys, reproducing there and infecting the urine. Infection of the liver or kidneys can be fatal for animals if the infection progresses, causing severe damage to these organs. Younger animals with less developed immune systems are at the highest risk for severe complications.
Common Symptoms include sudden fever and illness, sore muscles, reluctance to move, stiffness in muscles, legs, stiff gait, shivering, weakness, depression, lack of appetite, increased thirst and urination, inability to urinate, rapid dehydration, vomiting, possibly with blood, diarrhea – with or without blood in stool, bloody vaginal discharge, dark red speckled gums (petechiae), yellow skin, spontaneous cough, difficulty breathing, fast breathing, irregular pulse, runny nose, swelling of the mucous membrane and mild swelling of the lymph nodes