SACRAMENTO — As surgery wrapped up here on Tuesday, those in the operating room took turns posing for pictures and petting the broad head of their patient.
Patients don’t come much more unique than Castro.
At 15 years old, the Sacramento Zoo resident stands as the oldest breeding Sumatran tiger among the 120 critically endangered animals in captivity. Fewer than 700 of their kind remain in the wild.
“It’s incredible that the community is able to come together and really provide Castro with the best possible quality of care that we can, so we can make sure he has the highest quality of life that he can,” say Ray Wack, senior veterinarian for the zoo and at UC Davis.
It’s been a rough year for Castro.
He’s undergone four rounds of chemotherapy for lymphoma, a form of cancer, since February, taking drugs hidden in his food. More recently, he was diagnosed with stones in his ureters, the ducts through which urine passes from the kidneys to the bladder.
Born at the Audubon Zoo in New Orleans, Castro and his mother arrived in Sacramento in 1999. Two years later, another female arrived: the nervous, petite (at 180 to 200 pounds) Bahagia. It took six years to introduce her to the intimidating, 300- to 315-pound Castro.
They’ve since produced five living cubs, including Castro Jr., or C.J., who was born in March and already weighs 75 pounds. Also this year: Another of Castro and Baha’s cubs, a male born in 2007 and since relocated to the San Francisco Zoo, made Castro and Bahagia grandparents.
On Tuesday morning, Castro was hit with a blow dart syringe while he was inside his night holding area. Soon unconscious, he was hoisted onto a van then unloaded at the zoo’s Murray Fowler Veterinary Hospital.
Inside, he was hooked up IVs, a tube was inserted into his windpipe, and a swatch of his belly and sides was shaved, exposing the pale, striped skin beneath his fur.
Some good news came right away: A preliminary test showed his red blood cell count nearly normal. While similar cancers have been reported in other tigers, most haven’t responded as well to treatment, Wack said.
The obstruction in the tiger’s left ureter had also largely resolved itself since his last checkup.
That left the stone in his right ureter. The original plan, Wack explained, was to use a tiny scope inserted into the tiger’s penis, traveling up through the bladder before placing a stent, a small tube, between the bladder and kidney, through which urine could flow through.
The surgeons were unable to find the opening within the bladder, however.
Instead, they inserted a needle through Castro’s side, then ran a fine wire through the kidney, down the ureter and into the bladder. Then they placed the stent over the top of that guidewire. In all, the procedure took four hours.
Back in his den, Castro received a drug to wake him up. By midafternoon, he was coming around more quickly than expected. If all goes as planned, he’ll be back on exhibit in two days.
“We think things went really well, but it’ll take us awhile to get his new lab work back and see how he does with his new stent,” said Wack, who has performed surgeries on animals from “insects to elephants.”
More than 30 specialists played some role in Castro’s surgery.
They included a pair of doctors from Sutter Medical Group, urologist Ken Ferguson and interventional radiologist Craig Glaiberman, and a cadre from the UCD School of Veterinary Medicine led by interventional radiologist and surgeon Bill Culp, urologist Carrie Palm and oncologist Rob Rebhun.
GE Healthcare brought in a fluoroscopy unit, allowing surgeons to follow their progress on a monitor, and a special surgery table, from which the tiger’s tail dangled.
Keepers Amanda Mayberry and Erik Bowker first noticed something wasn’t quite right with the big cat.
“He’s not overly aggressive, but he’s not overly sweet,” said Bowker, a UCD graduate, but at the start of the year, the tiger became more aggressive toward his keepers, stumbled occasionally and began losing interest in his daily five or six pounds of beef and cups of oversized chow.
“He just wasn’t the same cat,” Bowker said.
Since he’s started chemotherapy, Castro has found a taste for rabbit, eating one a day, along with the occasional guinea pig, and some chow. His weight was at 245 for the surgery.
Castro’s back to pulling down the bamboo in his enclosure and dragging it around. He’s also returned to another of his habits: moving barrels made of thick white plastic from where the keepers place them and positioning them where he wants them.
“You dedicate your life to taking care of these guys,” Mayberry said. “(Lymphoma) was kind of a devastating diagnosis, but with the care that our vet staff has provided … the amount of dedication they’ve shown has been very comforting.”
Schoolchildren and adults visiting the zoo stopped to watch the surgery Tuesday, peering through large windows and at a computer monitor.
Fourth-year UCD veterinary students Becky Pacheco and Jenny Gorman have worked with big cats before. This time, in the midst of rotations at the zoo, they were able to observe the surgery from its planning stages. They also had a rare chance to get close to a Sumatran tiger.
Gorman took a moment to pet his whiskers.
“They’re so thick compared to a domestic cat’s — they’re just ginormous. They feel like a broom,” Gorman said later. “The size of the animal just blows you away — it’s humbling to see how big they really are.”
— Reach Cory Golden at [email protected] or 530-747-8046. Follow him on Twitter at @cory_golden