SeaWorld rescues sea lion from La Jolla Cove carrying ‘rare but contagious’ bacterial infection

The SeaWorld San Diego Rescue Team releases a rehabilitated sea lion from La Jolla Cove back into the wild.
The SeaWorld San Diego Rescue Team releases a rehabilitated sea lion back into the wild after it had been taken from La Jolla Cove and treated for a bacterial infection.
(SeaWorld San Diego)

Along with the disease, which can be transmitted to dogs and humans, the pup had more than 100 rocks in his stomach. But after six weeks of treatment, he was released back into the wild.


A sea lion pup found at La Jolla Cove carrying a rare and contagious bacterial infection has been released back into the wild after being rescued and treated by SeaWorld San Diego.

The sea lion’s type of infection, the last of which had been seen at SeaWorld about eight years ago, is not only communicable — and potentially lethal — to other sea lions but also can be transmitted to dogs and humans.

In January, the SeaWorld Rescue Team was at The Cove on a report of another animal that may need care when it noticed a different sea lion that was isolated, underweight and lethargic.

“The sea lion we got the call about appeared to be OK, so we didn’t take it,” said rescue team curator Kim Peterson. “But the [sea lion pup] we did take was exhibiting some concerning behaviors and symptoms.”

The rescuers took the pup to SeaWorld for evaluation by a larger team and an onsite veterinarian. “The whole team agreed something was very, very wrong,” Peterson said.

“The veterinary team conducted diagnostics on the sea lion and they showed that he was suspicious for a disease called leptospirosis,” according to SeaWorld. “Targeted treatment was immediately initiated and eventually we confirmed that he was positive for this disease. Leptospirosis is a potentially lethal bacterial disease and considered an important zoonotic pathogen (which can spread between animals and people).”

The SeaWorld veterinary team examines a sea lion rescued from La Jolla Cove.
(SeaWorld San Diego)

Peterson said there have been leptospirosis outbreaks in other areas, but “I don’t recall one in San Diego. He could have got it elsewhere and brought it here.”

In humans, leptospirosis can cause a wide range of symptoms, some of which may be mistaken for other diseases. Some infected people, however, may have no symptoms at all, according to the Centers for Disease Control and Prevention.

Without treatment, the CDC says, leptospirosis can lead to kidney damage, meningitis (inflammation of the membrane around the brain and spinal cord), liver failure, respiratory distress and even death.

“The last positive case of leptospirosis we saw was eight years ago,” Peterson said. “So it is rare but contagious. We had to quarantine the pup and provide treatment. We gave him fluids and nutritional fish slurry and medication to make him comfortable. He stabilized pretty rapidly, and soon more diagnostics were done to make sure there was nothing else wrong.”

But there was.

In addition to the leptospirosis, the veterinary team found on an X-ray that the sea lion had ingested more than 100 rocks that would need to be removed for him to fully recover. Gastroscopy (introducing a tube-shaped camera via the mouth into the stomach) was performed and more than a pound and a half of rocks were removed — one at a time — from his stomach over a series of five procedures.

“Sea lions occasionally eat rocks, but I’ve never seen this many,” Peterson said. “There is no way of telling what would cause him to do it. He didn’t have a lot of room for food in his stomach because of all the rocks.”

The treatment took about six weeks overall, and now “he’s fabulous,” Peterson said. “His bloodwork was normal, he is moving really well and he’s back to normal weight.”

And this month he was released back into the wild.

“This all started because people were observant and paid attention to the animals and called us,” Peterson said. “So much of what we do is dependent on people calling us. We can’t do our job without the public’s help, and the community of La Jolla is really important to us and helps us help as many animals as we can. We really appreciate it.”

SeaWorld typically rescues sea lion pups that are malnourished or left behind while their mothers are out to sea hunting. They also may be entangled in fishing line or netting and/or injured from things such as a boat propeller or shark bite.

Peterson advised people who are tempted to interact with the local pinnipeds that “it’s always best to keep your distance from wildlife. That’s not just for the animal but for the safety of the onlooker. Wild animals are unpredictable, so there is a fine line between getting too close and getting a good look.”

The SeaWorld San Diego Rescue Team can be reached at (800) 541-SEAL (7325) or via email at ◆