There are many toxins, foods, drugs and diseases that can cause acute kidney injury in dogs. But did you know there’s a chance it could happen because your dog was swimming in a lake or playing in slow-moving water? Keep reading to learn more about leptospirosis and the potential effects it can have on your dog’s kidneys (and yours, too).
What Is Leptospirosis?
Leptospirosis (also called “lepto”) is an infection caused by bacteria in the Leptospira genus. Most mammals can be a carrier of the bacteria, meaning they can harbor the leptospires (bacteria) in their kidneys. Carriers don’t show signs of illness but they can still shed the infectious leptospires in their urine. For animals that do show signs of infection (including some dogs and people), symptoms can be mild or as severe as kidney and liver damage or death, depending on the strain of the bacteria and the age and health status of the infected animal.
Multiple Infection Sources
Leptospires are commonly found in soil, rivers, lakes and streams, or other areas with warm, slow-moving or stagnant water. Infected animals shed the bacteria in their urine, allowing entry of the bacteria into soil and water where they can survive for months. The shores of lakes and rivers, and wet, shaded grassy areas can also be home to the bacteria.
Dogs of any age and breed can become infected with leptospires through exposure to contaminated water and soil or through contact with an infected animal (e.g., from their urine, from a bite or by eating prey). The bacteria can enter their body through their eyes, nose, mouth and open skin wounds. So dogs can still become infected even if they aren’t playing around stagnant water.
It’s important to note that leptospirosis is a zoonotic disease, which means if your dog is infected, they can spread the infection to you or other family members. Just like dogs, people can also become infected from swimming or boating in contaminated water.
Most exposed dogs are carriers and don’t show any signs of leptospirosis. However, some dogs can develop mild symptoms and others can have life-threatening symptoms. Signs of leptospirosis include fever, shivering, vomiting, diarrhea, increased thirst and urination, sore muscles and jaundice (yellow gums, eyes and skin). In severe cases, bleeding disorders and liver and kidney damage can also occur.
How Does Leptospirosis Affect the Kidneys?
In severe cases, leptospirosis can cause acute kidney injury in dogs. The leptospires can enter the kidneys causing the space between the kidney tubules to become inflamed (interstitial nephritis). These tubules, whose job it is to filter waste products and fluid from the kidneys, can also become inflamed, dysfunctional and damaged from the leptospires, potentially causing restricted oxygen and blood flow to the kidneys (tubular necrosis).
Signs of acute kidney injury include changes in urination, vomiting, increased thirst, lethargy, abdominal pain and loss of appetite. The prognosis depends on how quickly leptospirosis can be diagnosed and treated, and how much damage was done to the kidneys. Dogs with acute kidney injury will typically require hospitalization, fluid therapy, medications and a renal diet. The damage to the kidneys can be permanent, so even if they survive the acute kidney injury, it may lead to chronic kidney disease.
A Leptospirosis Vaccine Is Available
Diagnosis of leptospirosis is confirmed by blood tests and urinalysis. Antibiotics are used to treat the infection and supportive care may also be needed if the symptoms are severe (e.g., IV fluids, kidney dialysis, oxygen therapy). Some dogs may have permanent kidney or liver damage and some dogs may not recover from the infection.
A vaccine is available against some of the most common Leptospira species and may help prevent an infection. This vaccine isn’t part of your dog’s core vaccine schedule, so ask your veterinarian if they recommend the leptospirosis vaccine for your dog.
Unfortunately, there is no way to immediately know if water or soil is contaminated with leptospires or if an animal is a carrier of leptospirosis. It’s a good idea to bring fresh water for your dog to drink if they are going to be swimming or playing around potentially contaminated water. And be vigilant for the signs of leptospirosis — early detection may help prevent the infection from causing acute kidney injury.