Leptospirosis in dogs is a bacterial threat often lurking in puddles, ponds, or damp soil. This infection can be serious, leading to kidney and liver complications. While it may sound worrisome, knowing the facts can help you keep your dog safe. In this article, we’ll cover how leptospirosis in dogs spreads, common clinical signs to watch for, and steps to prevent it. Fortunately, there are preventative measures you can take to reduce the risk for your dog.
What is leptospirosis in dogs?
Leptospirosis is an infectious disease caused when dogs become infected with spiral-shaped bacteria called Leptospira. These bacteria belong to a group known as spirochetes.
Different types of Leptospira bacteria, known as serogroups, can cause leptospirosis in dogs. These serogroups are often linked to specific animals, such as dogs, rats, raccoons, skunks, cows, pigs, horses, and mice. The prevalence of these serogroups can vary depending on the geographic location.
The most common serogroups of leptospirosis include Canicola, Icterohaemorrhagiae, Grippotyphosa, and Pomona.
How is leptospirosis spread?
Leptospirosis primarily spreads through the urine of infected animals, particularly wild rodents, but also domestic animals such as dogs, cats, and livestock. The bacteria can survive for weeks to months in urine-soaked soil, water, and other moist environments.
Dogs typically become infected when their mucous membranes (as in the mouth, nose, or eyes) or skin wounds (like cuts or scrapes) are exposed to urine or urine-contaminated water or soil. Infection can also be spread through urine-contaminated food or bedding, or the tissues or carcasses of infected animals.
There are rare instances when exposure to Leptospira bacteria occurs through breeding with or being bitten by infected animals. An infected mother dog may pass the bacteria to her unborn puppies through the placenta.
Where do dogs contract leptospirosis?
Leptospira bacteria thrive in warm, damp, and slightly alkaline environments. They are often found in stagnant or slow-moving water. Flooding can spread the bacteria in the soil, as it prevents contaminated animal urine from evaporating and allows the bacteria to survive longer in surface water. Even though Leptospira doesn’t reproduce outside a host, it can stay alive for months under the right conditions.
Dogs become infected primarily by drinking standing water sources including puddles and other contaminated sources
Many wild animals can carry leptospirosis bacteria without showing symptoms, contributing to the spread of the disease.
Dogs are more likely to contract leptospirosis from July through November, especially after heavy rainfall or flooding. The bacteria remain in the environment by infecting certain animals, called reservoir hosts. When other animals, called incidental hosts, contract leptospirosis, they usually experience more severe symptoms and can spread the bacteria for longer periods compared to reservoir hosts.
Infected urine, a bite from an infected animal, or consuming contaminated tissues are other ways in which dogs can contract leptospirosis. The disease can also be transmitted during mating or from an infected mother to her puppies through the placenta.
Indirect transmission can happen when dogs are exposed to water, soil, food, or bedding that has been contaminated with infected urine or tissues. Leptospira bacteria can enter a dog’s body through mucous membranes, damp or softened skin, and cuts or scrapes.
Additionally, being around livestock and wildlife has been identified as a risk factor for leptospirosis in dogs. Dogs living in crowded kennels also have a higher chance of getting infected. In urban areas, dogs are more likely to contract the disease through contact with infected rodents and their urine. It’s important to note that the number of dogs with leptospirosis in urban areas has been on the rise.
What are the symptoms of leptospirosis in infected dogs?
The symptoms of leptospirosis in dogs can range from mild to severe and may sometimes resemble other illnesses. The most common clinical signs include vomiting, lethargy, and anorexia. Different serovars of leptospirosis result in different organ diseases and symptom sets, therefore, there is a wide variety of signs and symptoms associated with leptospirosis in dogs.
One of the symptoms to watch for is abdominal pain, particularly in the context of acute kidney injury.
Leptospirosis in dogs has peracute and subacute forms. The peracute form is characterized by rapid onset. It usually occurs after exposure to high doses of Leptospira bacteria and can lead to death within a few days. Dogs that survive the peracute form may develop the subacute form of leptospirosis, which has a slower onset and less severe symptoms.
Symptoms of the peracute (rapid) form of leptospirosis, including acute kidney injury
- High fever
- Shivering
- Muscle tenderness
- Vomiting/diarrhea
- Stiff gait (walking)
- Yellowing of the skin or eyes (jaundice)
- Rapid breathing (tachypnea)
- Small, red spots on the skin (petechial hemorrhages)
- Nosebleeds (epistaxis)
- Bloody stools (hematochezia or melena)
- Vomiting blood (hematemesis)
- Decreased or absent urine output (oliguria or anuria)
- Acute kidney injury
Symptoms of the subacute form of leptospirosis
- Loss of appetite (anorexia)
- Vomiting
- Increased thirst (polydipsia) and urination (polyuria)
- Weight loss
- Liver disease
How is leptospirosis diagnosed in dogs?
Diagnosing leptospirosis in affected dogs can be challenging due to the variety of symptoms that can resemble other illnesses. Veterinarians typically use a combination of clinical signs, the dog’s history, and diagnostic tests to determine if a dog has leptospirosis.
Some common diagnostic methods include:
- Blood tests: A complete blood count (CBC) and blood chemistry panel can provide valuable information about a dog’s overall health and organ function. These tests can help identify abnormalities that may indicate leptospirosis, such as elevated liver enzymes, azotemia (elevated kidney levels) low platelet count, or anemia.
- Urine tests: A urinalysis can reveal the presence of the Leptospira bacteria in a dog’s urine. This test can also help detect any abnormalities in the kidneys, which can be affected by leptospirosis.
- Polymerase chain reaction (PCR): PCR testing is a highly sensitive method that can detect the DNA of the Leptospira bacteria in a dog’s blood, urine, or tissue samples. This test can help confirm a diagnosis of leptospirosis, even in the early stages of the infection.
- Serological tests: The most common serological test for diagnosing leptospirosis is the microscopic agglutination test (MAT). This test measures the dog’s antibody response to different Leptospira serovars. A positive result indicates exposure to the bacteria, but it does not necessarily confirm an active infection. In some cases, veterinarians may recommend additional serological tests to provide more information.
What are the treatment options for dogs with leptospirosis?
Antibiotic therapy is imperative for treating leptospirosis in dogs. Traditionally, penicillins or doxycycline have been the preferred treatments.
While penicillins can help manage the infection, they do not eliminate the bacteria from the kidneys. On the other hand, doxycycline is effective in eradicating bacteria and is currently the top choice among veterinarians for treating leptospirosis.
Dogs with leptospirosis may require additional care to manage their symptoms and support their overall health. Dogs suffering from severe disease may require intensive care. Supportive care can include:
- Fluid therapy: Intravenous (IV) fluids are often administered to help maintain hydration, correct electrolyte imbalances, and support kidney function.
- Medications for symptom management: Depending on the dog’s symptoms, the veterinarian may prescribe medications to control pain, and manage symptoms such as nausea and vomiting (such as Cerenia®). Additionally, to maintain liver health, supplemental therapies such as antioxidants (like SAMe) and choleretics (such as ursodeoxycholic acid) may also be prescribed.
What is the prognosis for dogs with leptospirosis?
Canine leptospirosis responds well to proper antibiotic treatment. When dogs receive aggressive fluid therapy and antibiotics, the prognosis is generally good, with survival rates around 80-90%. However, dogs with lung issues or infections from the Pomona serogroup may have a poorer outcome. In a study of 99 dogs with leptospirosis, 32 either passed away or were euthanized.
Potential complications include chronic kidney failure and long-lasting liver inflammation. It’s worth noting that up to 50% of dogs that survive the acute phase of leptospirosis may still experience impaired kidney function for over a year.
How can leptospirosis in dogs be prevented with the leptospirosis vaccine?
Controlling rodent populations, limiting access to potential infection sources like stagnant water, and isolating infected animals can help prevent the spread of leptospirosis. The leptospirosis vaccine, containing four serogroups (Canicola, Icterohaemorrhagiae, Grippotyphosa, and Pomona), is available in North America.
Vaccinated dogs are important in the prevention of leptospirosis, although there is some uncertainty about their susceptibility to other strains. Current vaccines protect against these serogroups for at least 6-8 months, and possibly up to 12 months. Dogs need annual vaccinations to maintain protection. The risk of reactions from leptospirosis vaccines is similar to that of other vaccines given to dogs.
Reducing the risk of infection from infected animals
To reduce the risk of infection from infected animals, it is essential to take precautions when handling or coming into contact with potentially infected animals or their environments. Here are some measures to reduce the risk:
- Avoid contact with wild animals, especially rodents, and their urine or feces.
- Wear protective clothing, including gloves and masks, when handling animals or their environments.
- Wash hands thoroughly with soap and water after handling animals or their environments.
- Clean and disinfect any surfaces or equipment that may have come into contact with infected animals or their environments.
- Avoid touching your face, especially your eyes, nose, and mouth, after handling animals or their environments.
- Ensure that your dog is up-to-date on its leptospirosis vaccination and preventatives.
- Keep your dog away from areas where wild animals may be present, such as wooded areas or areas with standing water.
- Avoid letting your dog drink from standing water or eat food that may be contaminated with infected animal urine.
Can people contract leptospirosis?
Leptospirosis is a zoonotic disease which means that it can affect both animals and humans. People may become infected through work-related or recreational exposure. Those at higher risk include veterinarians, farmers, animal caretakers, and sewer workers. An infected dog poses a relatively low risk of infecting humans but can still be a threat to other pets in the home, highlighting the importance of vaccination.
Infected dogs can carry and transmit Leptospira bacteria without showing symptoms, emphasizing the need for precautions among veterinary personnel and pet owners to prevent potential infection from urine and other bodily fluids.
Recreational activities like boating, freshwater swimming, and hunting can also lead to exposure. Immunocompromised individuals and children are particularly vulnerable to infection. In urban areas, contact with infected rodent urine is a common source of leptospirosis transmission.
In conclusion, leptospirosis is a significant bacterial infection that affects both dogs and humans. Early diagnosis and proper treatment typically lead to a better prognosis. Preventive measures, such as controlling rodent populations and avoiding contaminated water sources, play a vital role in minimizing the spread of the disease. Key symptoms in dogs include fever, shivering, muscle discomfort, loss of appetite, vomiting, and increased thirst. Vaccination is an essential tool for protecting dogs from leptospirosis, with annual vaccinations recommended for sustained immunity. By staying vigilant in recognizing symptoms and seeking veterinary care promptly, dog owners can greatly improve their pets’ chances of recovery and maintain their overall well-being.