Leptospirosis in Dogs: The Waterborne Disease You Should Know About
Leptospirosis is caused by Leptospira bacteria, shed in the urine of infected wildlife — particularly rats, foxes, hedgehogs, and deer. These bacteria can survive in soil and standing water for weeks. Any dog that paddles in puddles, swims in rivers, or walks through wet grass in areas frequented by wildlife is potentially exposed. Importantly, leptospirosis is a zoonosis — it can infect people too.
How Dogs Get Infected
- Contact with contaminated puddles, rivers, ponds, or waterlogged soil
- Direct contact with infected urine
- Through mucous membranes or open skin wounds
- Drinking from natural water sources
Who Is at Higher Risk?
- Dogs with high outdoor exposure — gundogs, working dogs, rural dogs
- Dogs that swim in or drink from rivers, ditches, or ponds
- Dogs in urban areas with rat populations
Symptoms
- Mild form: fever, lethargy, muscle stiffness, loss of appetite, vomiting
- Acute kidney injury: drinking more or less than usual, vomiting, abdominal pain, swollen kidneys on ultrasound
- Liver failure: jaundice (yellow tinge to gums/eyes), bleeding tendencies
- Leptospiral pulmonary haemorrhage syndrome (LPHS): bloody cough, respiratory distress — life-threatening
Diagnosis and Treatment
The MAT (microscopic agglutination test) is the gold standard for confirmation; PCR from blood or urine is used in the acute phase for rapid results. Treatment: penicillin or amoxicillin for the acute phase, followed by doxycycline for 2 weeks to eliminate renal shedding. Severe cases require intensive supportive care, potentially dialysis.
Vaccination
Leptospirosis vaccines require annual boosters — immunity wanes faster than with other core vaccines. Modern L4 vaccines cover four serovars and provide good protection. Recommended for any dog with outdoor exposure, contact with wildlife, or access to natural water. Ask your vet whether to include it in your dog's annual vaccine schedule based on lifestyle risk.
Log vaccination dates, boosters, and any illness episodes in Purzi. For dogs that spend time outdoors year-round, this record is particularly valuable.