Caring for SF Zoo’s aging animals 

Every week, animal keepers at the San Francisco Zoo inject 18-year-old Ming Wah with fluids to prolong her kidney function.

The aging snow leopard is the first of her species to ever undergo the procedure to treat kidney failure. The concept is simple: increased liquids keep her hydrated and allow her organs more opportunity to process and absorb essential minerals, ultimately keeping her alive.

Even in the wild, Ming Wah would have a few more years left to live, but this medical procedure could buy her some additional time.

The snow leopard is just one of more than 200 geriatric animals currently housed at the San Francisco Zoo, and as animals continue to live further into their twilight years in captivity, the costs associated with veterinary intervention are mounting.

Roughly one-third of the nearly 650 animals at the zoo need this kind of aging or geriatric care to keep them alive, according to Chief Veterinarian Jacqueline Jencek. The total cost for veterinary care for all animals at the zoo is $797,380 a year — a $35,000 increase over the department’s 2009 budget. And as these animals get older, the total cost for their care will only increase.

The zoo, which is on city land but managed and operated by the nonprofit San Francisco Zoological Society, has been in dire financial straits since a fatal Christmas Day tiger mauling that left a teenage park visitor dead in 2007.

The incident resulted in millions of dollars in costs for the zoo, including legal fees and an expensive remodel of its exhibits to make them safer. Attendance numbers have also subsequently decreased, making it difficult to raise revenue to offset mounting expenses.

While the costs of caring for an aging animal population can be burdensome, when the patients consist of 400-pound tigers, a grey seal with cataracts and penguins making records for every day they continue to live, it’s also increasingly difficult to assess the animals’ exact comfort needs.

Some of the most common geriatric care given to these elderly animals is related to arthritis and kidney disease.

Jencek said many times the elderly animals are given warm blankets or heat sources to warm aging joints and make it easier to move or ramps for better access to trees. Some require medications such as Ibuprofen for arthritis or chemotherapy for cancer.

“It’s like caring for an elderly family member,” Jencek said. “They require more care and comfort.”

Because of the intimate care from birth to old age, bonds can often form between caretaker and animal.

Animal keeper and curator of primates and carnivores Corinne MacDonald said that while the zoo tries to create as natural a habitat as possible, it’s often difficult to prevent those bonds from forming.

MacDonald said she had a particular affection for an orangutan named Rusty. Though he died of a heart attack 10 years ago, she said she still thinks of him often and has an empty place in her heart.

“He was a very special creature,” MacDonald said.

While MacDonald was partial to an Orangutan, Jencek is bonded to a 18-year-old koala named Leo.

In the wild, Jencek said, Leo would not have lived as long. As koalas age, their molars get worn down, making it difficult to sufficiently grind eucalyptus leaves as fine as they need to be. Koalas’ intestines then cannot absorb enough nutrients, ultimately leading to their demise. But worn molars are not a problem Leo needs to worry about. At the zoo he is hand-fed a slurry made of blended leaves that give him the right nutrients.

“It’s fascinating to see what care and proper nutrition can do,” Jencek said.

Despite an arsenal of tactics to help prolong the lives of the zoo’s geriatric population, like humans, it always helps to have good genes on their side. Leo’s dad lived until age 18, a bar Leo is about to pass. The Magellanic penguin named Captain is another zoo success story — at age 28, he has surpassed his expected lifespan by eight years, Jencek said.

But the quality of care can’t always save an animal from suffering, which is when discussions about whether to euthanize an animal take place, Jencek said.

“It’s not easy for any of us,” she said about making the decision to end an animal’s life. “But we are here for them,” and it will come to that “if we see that their quality of life is affected,” said Jencek.

The zoo’s most recent — and most well known — euthanasia was that of 18-year-old Siberian tiger Tony last month. He made headlines when the San Francisco Fire Department had to come to the zoo to rescue him from his own moat in March after he refused to move from his favorite area.

Tony suffered from dementia, weakness in his limbs and inflammatory bowel disease. After that incident, euthanasia seemed more likely to keepers.

“It’s always going to end,” MacDonald said of an animal’s life. “It’s a part of our jobs; we are sort of stewards for these animals.”

Kangaroo, monkeys, birds among zoo’s next generation

As one-third of the San Francisco Zoo’s animal population requires more geriatric care, a new generation of inhabitants is just taking shape.

Just this month a kangaroo baby joey finally poked his head out of his mother’s pouch, according to Lora LaMarca, spokeswoman for the zoo.

“That’s after months he’s been growing in there,” she said. “So he’s got some age.”

Joeys can stay in a pouch for seven or eight months before venturing outside.

Twin emperor tamarins — squirrel-sized monkeys — were also just born and animal keepers are eagerly waiting for three flamingo eggs to hatch.

Though keepers are excited about the potential for three new birds, the animals’ health is never truly known until they are hatched, LaMarca said.

“We animal people get suspicious of sharing this information because we don’t know the outcome,” she said. “We don’t know if they will be successful hatches.”

Other animals in their first stages of life include the gorilla Hasani, which means “handsome” in Swahili. He will turn two in December and was adopted by a surrogate mother, Bawang, after he was rejected by his birth mother.

The zoo, located off Sloat Boulevard, has 647 animals, about 215 of which are considered geriatric.

Though there is no specific plan that calls for the replacement of animals once they die or are euthanized, LaMarca said, the zoo does have a long-range animal collection plan that helps them determine which animals to bring to the zoo. The plan is not just that once one animal dies, they go out looking for another.

“It’s based on companionship or breeding,” LaMarca said. “We check availability and conservation needs too.”

— Andrea Koskey

Golden years

  • Challenges animals face with aging:
  • Arthritis
  • Kidney disease/failure
  • Liver disease/failure
  • Heart disease/failure
  • Dementia
  • Cancer
  • Geriatric muscle wasting
  • Cataracts/blindness
  • Dental disease/tooth loss

Source: San Francisco Zoo

San Francisco Zoo life

647 Animals, not including bugs and insects

250 Species

215 Animals considered geriatric

$16.7 million Zoo’s total operating budget

$797,380 Total cost of animals’ medical care

755,164 Visitors to the zoo during the 2010 fiscal year 

Source: Recreation and Parks Department


Senior citizens


Ming Wah

Species: Snow leopard

Age: 18

Medical problems: Kidney failure, arthritis

Life expectancy in the wild: 21 years



Species: Koala

Age: 18

Medical problems: Worn molars

Life expectancy in the wild: 13 to 18 years



Species: Chimpanzee

Age: 51

Medical problems: Arthritis, mammary cancer, kidney disease

Life expectancy in the wild: 45 years



Species: Sumatran tiger

Age: 21

Medical problems: Arthritis

Life expectancy in the wild: 10 to 15 years



Species: Black rhino

Age: 39

Medical problems: Dry skin

Life expectancy in the wild: 40 years


King Richard

Species: Great horned owl

Age: 48

Medical problems: Cataracts

Life expectancy in the wild: 15 years



Species: Magellanic penguin

Age: 28

Medical problems: Mild arthritis

Life expectancy in the wild: 15 to 20 years


Mr. Tibbits

Species: Warthog

Age: 15

Medical problems: arthritis

Life expectancy in the wild: 15 years


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