Community Updates
A carrier urinates in a body of water or soil. In wet conditions, Leptospira multiplies.
Dogs become infected by Leptospira through mucous membranes( e. g. gums) or open wounds.
Leptospirosis in Dogs
By Krista Williams, BSc, DVM, CCRP; Malcolm Weir, DVM, MSc, MPH; Catherine Barnette, DVM; Ernest Ward, DVM
WHAT IS LEPTOSPIROSIS?
Leptospirosis is an infectious disease caused by a type of bacteria called Leptospira. The disease causes severe damage to the kidney, liver, and other organs, and may be fatal in severe cases. Bacteria are passed in the urine of infected animals and can survive in the environment for long periods in warm, stagnant water or moist soil. Dogs can get the infection from other animals, including skunks, raccoons, opossums, rats, wolves, and other dogs.
The bacteria that cause leptospirosis, commonly called leptospires, thrive in water and have a helical or spiral shape with a characteristic hook on one or both ends. There are many species and serovars( strains) of Leptospira, some of which cause disease in dogs. Cats can become infected through eating rodents, and may develop disease( Leptospirosis), but it is considered rare.
HOW COMMON IS LEPTOSPIROSIS?
Leptospirosis is uncommon in areas where dogs are routinely vaccinated.
However, disease outbreaks are still seen occasionally because vaccines protect against only the four most prevalent strains of Leptospira. Leptospirosis was once more common in rural, wooded areas, but it is now commonly found in urban settings.
HOW ARE DOGS INFECTED?
Leptospira bacteria are carried mainly by rats and other rodents but can be carried by almost any mammal, including people. Infected or recovered carrier dogs may act as a source of the infection.
Leptospira bacteria is shed in the urine of infected animals that then contaminates soil or water. In wet conditions, the bacteria reproduce, resulting in higher numbers of infective organisms. Infection most commonly occurs when contaminated water or soil contacts an animal’ s mucus membranes( i. e., gums) or damaged or diseased skin.
For instance, if a dog were to walk in contaminated mud, they may become infected through their skin if they have any skin lesions on or around their
feet. Infection can also occur animalto-animal through bite wounds, by ingestion of an infected animal( predation), sexual transmission, and transmission in utero from mother to pups. The incubation period( from infection to onset of clinical signs) is usually four to twelve days.
WHAT ARE THE SIGNS OF LEPTOSPIROSIS?
Many Leptospira infections go undetected, but other cases can be life-threatening. Certain strains of Leptospira are more likely to be associated with disease than other strains.
The most common clinical signs associated with leptospirosis are those caused by acute( sudden) kidney injury and liver dysfunction, although the bacteria can also affect other organs and functions, such as the lungs, and may cause uncontrolled bleeding, which can lead to many different clinical signs. Common signs of leptospirosis include reduced or no appetite, lethargy, and high fever.
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