Effective Treatment & Prevention of Canine Leptospirosi

Many pet owners may not be wellinformed about Leptospirosis in dogs, but during routine vaccinations at the vet's office, it's common for veterinarians to recommend the Leptospirosis vaccine for our furry companions.

Leptospirosis is an infectious disease caused by a bacterium known as Leptospira. This illness often leads to severe damage to the kidneys and liver of affected dogs, and in severe cases, it can even be lifethreatening. The bacterium is widespread in soil and water across the globe, with many different strains of Leptospira capable of infecting dogs. What's more, it's a zoonotic disease, meaning it can be transmitted from animals to humans. When humans contract the disease, they may experience flulike symptoms and can suffer from serious liver or kidney damage. Most cases of Leptospirosis in humans are associated with waterrelated recreational activities, and infections from contact with infected pets are less common.

The bacteria have a spiral shape and can penetrate the skin to enter the body's tissue system. They can then spread throughout the body, reproducing in the liver, kidneys, eyes, reproductive system, and central nervous system. After the initial infection, dogs may experience a fever due to the bacterial infection, but these symptoms usually subside as the body's antibodies react, allowing the dog to clear most of the bacteria from its system.

The extent of the bacteria's impact on organs largely depends on the dog's immune system and its ability to completely eradicate the infection. Even if a dog's immune system can fight off the bacteria, Leptospira can remain in the kidneys and continue to reproduce there. If the infection spreads further, the dog's kidneys and liver may be damaged, leading to severe organ harm. Thus, dogs with underdeveloped immune systems face the highest risk of illness and complications. Leptospirosis is more common in warm, wet regions with high annual rainfall, but it can occur anywhere.

Causes of Canine Leptospirosis

Any dog can be at risk of infection, but adult male large breeds seem to have a higher infection rate. Most infections occur in spring and early autumn. Dogs typically become infected by direct contact with the urine of an infected animal. Additionally, dogs can contract the disease by coming into contact with water, soil, food, or bedding contaminated with infected animal urine. Infections through bites or consumption of infected tissue or carcasses are rare, and the disease can also be transmitted via the placenta.

It's important to note that once Leptospira enters the body, it can spread to many types of tissues in the dog. While the immune system can clear most of the bacteria from the body, some may "hide" in the kidneys, where they can reproduce. The bacteria can also act as a host, continuing to excrete them into the environment; however, they can survive in the environment for weeks or even months.

Symptoms of Canine Leptospirosis

Dogs with Leptospirosis may exhibit a range of clinical symptoms depending on the severity of the illness, which can vary based on the dog's age, immune response, vaccination status, the strain of Leptospira, and other factors. Some infected dogs may show mild symptoms or none at all, but severe cases can be lifethreatening. Common clinical signs and symptoms in dogs with Leptospirosis include:

Sudden fever

Muscle pain and reluctance to move

Stiffness in leg muscles and gait

Trembling

Loss of appetite

Increased thirst and urination, which may indicate chronic kidney failure

Dehydration

Vomiting, which may contain blood

Diarrhea, which may contain blood

Bloody discharge from the female dog's vagina

Dark red spots on the gums

Anemia symptoms

Spontaneous coughing

Irregular pulse, difficulty breathing, or rapid breathing

Discharge from the nose

Swollen lymph nodes

Jaundice, characterized by yellowing of the skin and mucous membranes

Diagnosis of Canine Leptospirosis

As Leptospirosis is a zoonotic disease, veterinarians take extra precautions when diagnosing it. A general diagnosis is often made based on the dog's medical history, vaccination status, and clinical symptoms. Additional tests may include a complete blood count, blood chemistry tests, and urine analysis. Common abnormalities in dogs with Leptospirosis include:

Complete blood count: Increased white blood cell count (infection or tissue damage), decreased platelet count (infection or severe disease), and sometimes a decrease in red blood cell count (bleeding).

Blood chemistry tests: Elevated levels of serum urea, creatinine, phosphorus, bilirubin, and liver enzymes.

Urine analysis: Presence of protein in the urine (proteinuria) and occasionally blood in the urine, indicating kidney damage.

Other diagnostic tests, such as bacterial DNA detection (PCR) and microscopic agglutination test (MAT), can be used for final confirmation. Both tests can diagnose Leptospira infection, but each has its limitations. In some cases, both tests are used together for diagnosis. PCR is a rapid test that detects the DNA of Leptospira in blood or urine, with urine being the preferred sample due to the bacteria's presence in the kidneys. The test is fast and inexpensive, but it must be performed before antibiotics are administered, as Leptospira can be easily killed by antibiotics, leading to falsepositive results. MAT detects the presence of antibodies against Leptospira in the dog's blood. If the antibody titer (also known as the agglutination titer) is high or shows a gradual increase over time, the dog is confirmed to be infected. While a good test, it is slower than PCR and typically takes a few days to get results.

Treatment of Canine Leptospirosis

Veterinarians develop treatment plans based on the severity of the disease. Dogs experiencing vomiting may be given antiemetic medications, and those with severe bleeding may require blood transfusions. Antibiotics are highly effective for treating Leptospirosis, and most dogs respond quickly once they begin treatment. Treatment is typically divided into two stages: the first stage is to quickly clear the most severe or acute infection, and the second stage is to clear the "hidden" infection in the dog's body tissues. Dogs with severe kidney or liver damage may need hospitalization and treatment, including intravenous fluids and other medications. Dogs with severe infections may still suffer irreversible organ damage due to the bacterial infection, leading to rapid organ deterioration and death.

In conclusion, while we can't prevent Leptospirosis 100%, regular vaccination can help reduce the incidence of the disease. In highrisk areas for Leptospira (wet, rainy regions), it's best to avoid letting dogs swim or play in ponds or rivers. Try to avoid contact with the urine of infected dogs, and if urine needs to be handled, wear gloves or take other protective measures. Maintain good hygiene, including frequent handwashing, and disinfect the surface of urine from infected dogs. Follow your veterinarian's advice for treating infected dogs and ensure that all medications are administered as prescribed.