Leptospirosis - Is your Dog Protected?

Leptospirosis is an infectious disease caused by the bacteria Leptospira. It is a zoonotic disease, meaning it can be passed from animals to humans; however, human-to-human transmission is considered rare. Leptospira bacteria can infect and be carried by farm animals including cattle, pigs, goats, and dogs. Wildlife and rodents are also common carriers of the disease. 

Leptospira bacteria are excreted in the urine of infected hosts, which can contaminate groundwater, soil, and vegetation. The bacteria thrive in warm, moist environments and slow-moving water, particularly after rain and/or flooding. Even once surface water clears, soil can remain contaminated for months. Infection occurs when the bacteria enter the body through broken skin (such as cuts and abrasions) or through mucous membranes including the nose, mouth, and eyes. 

Leptospirosis was once considered primarily a rural disease and posed little risk to urban areas. However, the prevalence of the disease has increased significantly due to climate change. Rising temperatures and more frequent extreme weather events, such as heavy rainfall, flooding, and heatwaves - are creating ideal conditions for the bacteria to survive and spread. 

Infection in Dogs

Symptoms of leptospirosis can vary significantly between animals, with some dogs appearing subclinical (showing no obvious symptoms). More severe illness is generally seen in young animals, geriatric patients, and those who are immunocompromised. 

When dogs do become sick, signs tend to be non-specific. Common clinical signs include: 

The infection spreads rapidly into the bloodstream, leading to inflammation of the blood vessels. This can cause fever, abnormal bruising, and tissue oedema (swelling caused by fluid build-up). Clinical signs typically begin 2-14 days after infection, although some dogs may not show symptoms for up to 30 days. 

Approximately two weeks after infection, the bacteria can spread to the kidneys, where they cause ongoing inflammation and pain and may progress to kidney failure, including the inability to urinate. In some cases, the liver may also be affected, leading to liver failure. In severe cases, the infection can spread to the lungs, resulting in Leptospira Pulmonary Haemorrhage Syndrome, which causes bleeding in the lungs, difficulty breathing, and, occasionally, damage to the heart muscle. 

Diagnosis and Treatment

Diagnosing leptospirosis can be challenging, as it often mimics other, more common illnesses. Diagnosis is typically based on a combination of clinical examination, lifestyle and travel history, blood tests, and urinalysis. In some cases, further diagnostic imaging such as radiographs (X-rays) and/or ultrasound may be required. 

Unfortunately, there is no single cure for leptospirosis. Treatment focuses on supportive care tailored to the dog’s symptoms and may include fluid therapy, oxygen therapy, nutritional support, and appropriate medications. Targeted antimicrobial therapy with a course of antibiotics is also required. 

Prevention

Dogs can be protected against leptospirosis through vaccination. Leptoguard can be administered as part of routine puppy vaccinations from 12 weeks of age. An initial course of two vaccinations is required, followed by annual boosters. 

As we are located in the far south, vaccination was previously recommended mainly for dogs living on farmland or travelling to the far north. However, with leptospirosis becoming increasingly prevalent further south, we now encourage all dog owners to assess their dog’s individual risk. 

Risk factors include: 

If you are unsure whether your dog should be vaccinated against leptospirosis, please feel free to speak with our team. We are happy to help assess your pet’s risk factors and support you in making an informed decision.