What is Leptospirosis?
Leptospirosis is a bacterial infection spread through the urine of infected animals. It is a serious zoonotic disease, meaning it can be transmitted from animals to humans through contact with infected urine.
There are several forms of leptospirosis that commonly affect dogs:
Weil’s Disease (Leptospira icterohaemorrhagiae)
Rats are the primary carriers of this strain. Dogs can become infected either directly through contact with rat urine or indirectly by drinking or swimming in water contaminated by infected rats.
Symptoms can range from mild, non-specific signs such as lethargy and depression, to severe signs including abdominal pain, jaundice, liver damage, and in some cases, death. Dogs that recover may become carriers, shedding bacteria in their urine.
Leptospira canicola
Dogs themselves are the main carriers of this strain. It primarily affects the kidneys, with clinical signs ranging from mild symptoms to kidney failure or sudden death. As with Weil’s disease, recovered dogs may continue to shed the bacteria.
Other Serovars
A serovar is a distinct variation within a species of bacteria. In recent years, strains other than icterohaemorrhagiae and canicola have been identified as causes of leptospirosis. In some countries, these other serovars are more common.
Experts now recommend vaccines covering a broader range of serovars to ensure adequate protection. In the UK, the Bratislava serovar is significant, while dogs travelling to or from parts of continental Europe may be exposed to Grippotyphosa. A new vaccine now protects against all four major serovar groups identified in the UK and Europe. Discuss your pet’s individual risk with your vet.
Which Dogs are at Risk?
Any dog that goes outdoors, has contact with rodents, or encounters areas contaminated with urine is at risk. Because of the widespread nature of the disease, most dogs in the UK should receive an annual leptospirosis vaccination. Vaccination not only protects the individual dog but also reduces the shedding of bacteria in urine, helping to prevent the spread of infection.
How is Leptospirosis Spread?
Once ingested, the bacteria enter the bloodstream via the mucous membranes, then replicate in tissues such as the kidneys, liver, and spleen. They are eventually excreted in the urine, contaminating the environment.
How is Leptospirosis Diagnosed?
Your vet will consider leptospirosis based on symptoms, vaccination history, and a physical examination. Blood tests may show reduced white blood cell counts and signs of liver or kidney damage. Further blood analysis can indicate exposure to leptospires.
Management of Leptospirosis
Leptospirosis can be fatal, but it is treatable. Treatment may include aggressive therapies such as blood transfusions and appropriate antibiotics. Survival is not guaranteed, so early veterinary intervention is crucial.
Vaccination to Prevent Leptospirosis
Prevention through vaccination is far more effective than treatment. A new leptospirosis vaccine provides enhanced protection and is the only licensed vaccine proven to reduce renal shedding, stopping the spread of bacteria via urine.
Dogs should be re-vaccinated annually, as protection begins to decline after 12 months.