Not unlike other aging mammals, the Sacramento Zoo’s Sumatran tiger named Castro underwent a urologic operation Tuesday.
To provide the tiger with relief from urinary tract stones, medical experts inserted a thin, flexible tube to help drain urine from the big cat’s kidney to the bladder. He came through the minimally invasive operation like a champ.
“Castro did well today, said Sacramento Zoo and UC Davis senior veterinarian Ray Wack. “We are very happy with the way he handled the anesthesia and procedures, and he’s up and recovering in his building.”
Castro, 15, is a tough old tiger. Sumatrans, the smallest of the world's six subspecies of tigers, grow to weigh 165 to about 300 pounds, and live for 15 to 20 years.
“Castro is the oldest breeding male Sumatran in the country,” Wack said.
Long ago in cat years, Castro earned his stripes when it comes to keeping the gene pool deep for the critically endangered species.
The zoo’s female tiger, Bahagia, gave birth to a tiger cub March 3. She and the cub's father, Castro, have produced five surviving offspring.
In addition to his urinary tract troubles, Castro was diagnosed in February with lymphoma, a form of cancer.
“Keepers noticed he was not eating as eagerly and had lost a little weight,” Wack said. “The lymphoma was probably centered in his spleen.”
Since his lymphoma diagnosis, Castro has been undergone chemotherapy and is doing better.
Meanwhile, he developed small stones in his ureters, which connect the kidneys with the bladder. If the stones were to get larger or dislodge, they could completely block Castro’s ability to urinate.
“That would be an emergency,” Wack said. “He would get really sick, really quick.”
Wack said help from the University of California, Davis, veterinary school, equipment manufacturers and Sutter Hospital made the operation possible. Normally, the operation would cost $10,000, Wack said. But with all the help of the community, Castro’s operation cost will only be $2,000.
The plan was to insert custom made, “tiger sized” tubes to make the ureters stay open. Using specialized equipment, a scope was sent up his urinary tract into his bladder.
The goal was to place tubes in without ever having to cut the tiger with a scalpel, Wack said.
A team of about 30 specialists worked on Castro. In the end, only one plastic stent needed to placed inside the tiger, Wack said.
“Hopefully, that will fix that partial obstruction,” Wack said. “We are trying to give him the best quality of life we can. He’s getting up there.”
In addition, his lymphoma was evaluated in terms of how well the disease was responding to chemotherapy. Wack said initial tests appear to show him responding well.
Although he looks soft and cuddly when asleep on an operating table, Castro can bite and claw like any predator.
In 2003, the tiger went at a zookeeper who was treated for puncture wounds on his neck, right shoulder and left leg. A zoo volunteer came to the rescue, banging Castro on the head a couple of times with a shovel.
Fewer than 500 Sumatran tigers are believed to exist in the wild on the Indonesian island of Sumatra. About 200 live in zoos around the world.
The tigers living free on the Indonesian island of Sumatra are threatened by destruction of their forest home and poachers who collect their hides as well as body parts for supposed medicinal properties.