Leptospirose

Weil’s Disease in Dogs: Symptoms, Prevention, and Treatment

Introduction
When the weather gets nice, it can be wonderful for both people and dogs to take a dip in lakes or ponds. But beware: swimming in stagnant water can cause both humans and dogs to contract Weil’s disease!

Weil’s disease is a well-known form of leptospirosis. Leptospirosis is caused by Leptospira spp., a type of bacteria. This disease can have serious consequences for dogs as well as humans because it is a zoonosis, meaning it can be transmitted from animals to people. Fortunately, cats cannot be infected.

Transmission
Dogs contract Weil’s disease through wild animals in nature, often via rats. Rodents carry the bacteria, which is present in their urine, though they do not get sick from it themselves. However, dogs and humans can become very ill from Leptospira.

The bacteria enter stagnant water through rat urine, and dogs can become infected by swimming in or drinking from this water, for example from muddy puddles.

Dogs can also become infected through direct contact with wild rodents (eating carcasses or bite wounds).

Symptoms

Infected dogs show signs such as fever (often very high), reduced appetite, lethargy, vomiting, and diarrhea. Sometimes, they also experience joint and muscle pain as well as neurological symptoms.

Dogs may develop kidney and liver failure. Kidney failure causes increased drinking and urination, while liver failure can result in jaundice. In dogs, jaundice appears as yellow discoloration of the mucous membranes and eventually also the skin.

With proper treatment, dogs can fully recover from Weil’s disease. In severe cases, however, a dog with leptospirosis may die due to kidney or liver failure.

Diagnosis

Weil’s disease can be detected through a blood test. An infected animal produces antibodies against the bacteria, which can be identified in the blood.

Treatment

Weil’s disease is treated with antibiotics. In addition, supportive care is often necessary, such as hospitalization and intravenous fluids. Complete the full course of antibiotics as prescribed by your veterinarian. Sometimes a second course is needed to fully combat leptospirosis. If the treatment is not completed, the dog can continue to infect other dogs and humans for months.

Prevention – Vaccination

Fortunately, there is a vaccine available to protect dogs against leptospirosis. It is advisable to have your dog vaccinated annually against Weil’s disease.

Since 2013, a new vaccine has been available that protects against four instead of two types of Leptospira. If you and your veterinarian decide to switch to the new vaccine, the first vaccination must be repeated after 4 to 6 weeks to ensure proper protection against the new variants. After that, the vaccination should be repeated annually.

It is recommended to prevent dogs from swimming in stagnant water, especially in shaded areas, since sunlight quickly kills the bacteria. Also, try to prevent your dog from drinking water where rats are present.

In Humans

Humans can contract Weil’s disease from an infected dog. If your dog becomes ill, follow your veterinarian’s instructions carefully and maintain good hygiene. It is advised to be cautious when handling the dog’s urine, wash your hands thoroughly, and generally maintain good household hygiene.

The severity of symptoms in humans can vary. It may be limited to flu-like symptoms, but in severe cases, the infection can be fatal. Therefore, it is essential to take preventive measures and have dogs vaccinated against Weil’s disease.