Leptospirosis in Seals?

(c)2025 The Marine Mammal Center

 People know -or should do- about leptospirosis in foxes with the likely cause being rats and lack of immunity in some foxes.

So lepto in seals?

According to the California Marine Mammal Centre https://www.marinemammalcenter.org/science-conservation/research-library/leptospirosis

“Every four to five years, The Marine Mammal Center sees a surge in the number of California sea lions that are admitted with symptoms of leptospirosis.

"This bacterial infection affects the  kidneys and can be lethal. If not treated, the bacteria can cause irreversible kidney damage.

“What Is Leptospirosis?

"Leptospirosis is caused by a spiral-shaped bacteria called Leptospira. Veterinarians can usually identify leptospirosis in a patient even before laboratory tests confirm a diagnosis because of the infection's distinctive symptoms in California sea lions, which include drinking water and folding the flippers over the abdomen.

“Marine mammals generally do not need to drink water because they receive all the hydration they need from food sources. But when they are infected with the Leptospira, their kidneys stop functioning properly and cannot filter toxins or regulate hydration.

 "Sea lions diagnosed with leptospirosis are treated with antibiotics, fluids and other supportive care, such as gastroprotectants for stomach and intestinal ulcers. Unfortunately, even with treatment, roughly two-thirds of the animals that strand with acute leptospirosis do not survive."

Leptospirosis in seals is caused by infection with the bacteria Leptospirosis interrogans, which is spread through contact with the urine or other bodily fluids of infected animals, or through contaminated water or soil. The bacteria can also be found in the kidneys of infected animals and are shed in their urine, contaminating the environment.