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Leptospirosis and Your Pet

Owner Sitting with Dog at the Dock by the Lake

What is Leptospirosis?

Leptospirosis, or Lepto for short, is a worldwide bacteria found in the environment that can infect animals and people. Due to their lifestyle, intact outdoor male working dogs are most often affected, but any dog can contract the disease. Cats do not appear to develop illness from Lepto.

How do dogs get Lepto?

Lepto is associated with wildlife and stagnant water. When an infected wild animal or dog urinates, a large amount of spirochetes are deposited in that area. If your dog licks or eats anything contaminated, they will become infected. This occurs most commonly in suburban to rural environments but can occur with rodents in urban environments. Keeping dogs away from stagnant lakes, ponds, and areas of flooding will help to minimize infection.

Can Lepto infect my family and me?

Yes. Lepto is the most common zoonotic disease (animal to human) in the world. Infected people may become very ill and suffer acute kidney injury. Pregnant women, children, the elderly, chemotherapy patients, HIV-positive individuals, and other immunocompromised persons are particularly at risk for infection and complications. Prevention is critical – if you suspect your dog is infected, avoid areas he/she has urinated on and have him/her promptly tested by a veterinarian. If you think you or a family member may be infected, contact your family physician for guidance immediately.

How can I tell if my dog has Lepto?

Dogs infected with Lepto have a wide range of presentations, from asymptomatic to critically ill. Approximately 7-10 days after exposure, clinical signs to watch for include lethargy, anorexia, vomiting and/or diarrhea with or without blood, and urinating large amounts. Upon physical exam by a veterinarian, evidence of dehydration, hypovolemia (low blood volume), muscle pain, abdominal discomfort, abnormal bruising, ocular inflammation, and increased lung sounds, rate, and effort may be appreciated.

How is Lepto diagnosed?

Initial diagnostics typically include a complete blood count and chemistry, which may reveal an elevated neutrophil count (associated with inflammation/infection), mild to moderate anemia, low blood platelets, elevated kidney values and phosphorus, elevated liver values, low albumin (the main blood protein), low sodium, and low or high potassium. A urinalysis may reveal poorly concentrated urine with elevated amounts of glucose and protein, as well as casts (solid debris from damaged kidneys). Chest radiographs may show changes consistent with hemorrhage into the lungs, while an abdominal ultrasound may reveal an enlarged liver, spleen, and kidneys, as well as further evidence of kidney disease. To confirm a Lepto infection, urine, and blood are sent off for antibody titer or PCR testing. In some cases, this will have to be repeated in 2-4 weeks.

How is Lepto treated?

Depending on the severity of the disease, hospitalization on IV fluids may or may not be required for rehydration, to replace continued fluid losses via excessive urination, and to protect the kidneys. Doxycycline is the antibiotic of choice for definitive treatment, but severely ill patients may require an initial course of ampicillin or another similar antibiotic to clear Lepto from the bloodstream. Other potential complications, such as liver disease and pulmonary hemorrhage, may require specific therapies and monitoring, such as liver protectants or recheck chest radiographs. Clinically affected dogs have a 70-85% survival rate, although some are left with permanent kidney damage which may or may not affect long-term survival and quality of life.