Dr. Shawn Johnson from The Marine Mammal Center assisted with the anesthesia and cataract surgeries for two South American sea lions in Puerto Vallarta, Mexico.
I have a pretty great job right here at The Marine Mammal Center as Director of Veterinary Science, but I got an extra treat in January when I traveled to Puerto Vallarta, Mexico to assist with the anesthesia and cataract surgery for two South American sea lions that live at Vallarta Adventures! These surgeries are a major investment in the health care and well-being of these animals, and demonstrate the facility's dedication to the animals’ welfare.
The patients were two adults, Sayula, an 8-year-old female weighing 242 lbs, and Nano, a 9-year-old male weighing a hefty 550 lbs. These animals were blind in both eyes due to bilateral cataracts.
It appears that the greatest risk for cataracts is UV light exposure and trauma. Although we do occasionally see cataracts in wild stranded animals, we don’t know how common it is in wild populations. However, it is common with sea lions in captivity. They live a lot longer than their wild counterparts so they develop geriatric diseases such as cataracts.
Once again I had the honor to work with Dr. Carmen Colitz. She is a veterinary ophthalmologist who travels the world to consult on marine mammal ocular disease. She has performed over 100 cataract surgeries in pinnipeds and last year graciously volunteered her skills to The Marine Mammal Center, performing cataract surgery on our gunshot California sea lion patient Old Ray.
Because of the unique physiologic adaptation marine mammals have developed for diving and their large size, long anesthetic procedures can be tricky. To ensure a successful procedure, Dr. Colitz is assisted by Dr. James Bailey who specializes in marine mammal anesthesiology. His skills and knowledge were crucial in keeping these large sea lions under anesthesia for the 5 hour procedure. Because of my own expertise in sea lion anesthesia and surgery, I was asked to provide additional veterinary support during this procedure.
Just like at a human hospital, there are many things that need to be attended to during a complicated surgical procedure. These surgeries required a large team of veterinarians and vet technicians, so my role was to manage the surgical room and, using ultrasound, insert a jugular catheter into the patients' necks to administer the paralytic agents necessary to perform the surgeries, as well as giving other medications and fluids. We were also able to place arterial catheters in the front flippers of both sea lions, allowing us to measure blood pressure, which is vital data needed to manage the anesthesia and ensure a successful recovery.
We were assisted by the facility’s own veterinarians, two technicians, and six trainers (as you might imagine, it takes a lot of people to move a ¼ ton sea lion!). During recovery, the sea lions had to remain out of the water for nearly 3 weeks to allow the surgical incisions in their eyes to heal. Thanks to a great team, both surgeries were successfully completed and Nano and Sayula fully recovered!
Assisting with these types of specialty procedures not only allows me to share and further hone my skills and knowledge, ultimately it improves the lives of pinnipeds in captive care. I also gain from working with new species and establishing relationships with other veterinary specialists. So little is known about marine mammals, so these learning opportunities are invaluable and will hopefully allow me to apply these latest findings to our own patients here at The Marine Mammal Center.
-Dr. Shawn Johnson
Read about another patient that underwent cataract surgery
Learn about South American sea lions
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