[monkeywire] Toledo pioneers drugging gorillas
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Mon Sep 12 10:16:40 EDT 2005
Zoos using drugs to help manage anxious animals
Toledo has wealth of success stories
By JENNI LAIDMAN
BLADE SCIENCE WRITER
Johari the gorilla is on antidepressants. It eases her PMS.
When the Toledo Zoo needed calm zebras, it used an antipsychotic
medication to quiet their jitters. Zoo staffers tried to soothe
wildebeests with antipsychotic medication for eight months last year,
and even occasionally this year. A swamp monkey was dosed with the
antipsychotic, but it didn't help her get along with her daughter. It
wasn't much good for ostrich aggression either. Yet a little Valium
calmed the silverback gorilla when one of the females had a doctor
visit. And Prozac helped a female orangutan negotiate life in her
Now that humans have warmly embraced citizenship in the Prozac
Nation, zoo animals are making tentative gallops, flights, and
knuckle-walks into the world of psychotropic pharmaceuticals.
In the last decade, zoos across the nation have turned to
antidepressants, tranquilizers, and even antipsychotic drugs such as
haloperidol, sold as Haldol, to ease behavioral problems in zoo
"They're definitely a wonderful management tool, and that's how we
look at them," said the Toledo Zoo's mammal curator, Randi Meyerson.
"To be able to just take the edge off puts us a little more at ease."
Klechka was 300 pounds of sinewy orange ferocity. Then keepers hung
shade cloth in the Amur tiger's enclosure to keep him out of the sun.
(Amur tigers are also called Siberian tigers.)
That did it. He morphed from brave tiger into cowardly lion.
"It was terrifying for him," Ms. Meyerson said. "He even stopped eating."
To help Klechka get accustomed to his altered environment, the big
cat received a low dose of Valium for two days. It did the trick. The
2-year-old tiger went back to being his normal, formidable self.
Most often, the drugs are short-term interventions to help animals
through a bad patch, but occasionally, they become a long-term
treatment for animal behavior. Take the case of Johari, a 17-year-old
To hear gorilla keeper Char Petiniot describe interactions among the
Toledo Zoo's gorillas is to follow a soap opera featuring a
greater-than-average number of bite wounds.
Johari is a nervous gorilla at the best of times, plucking hair from
her arms and face the way some people chew fingernails. To make
matters worse, her family group has had more than its share of drama,
with members moving in and out of the group, and alliances constantly
shifting. When Kwisha, a silverback, returned to the group in 2002
after a lengthy separation, Johari kept getting injured in fights
At first, keepers blamed Kwisha. He attacked Johari on a number of
occasions, and many of the attacks required medical treatment. Johari
had to be knocked out, separated from her group, and given time to
heal. On return, she'd be attacked again.
Things got so serious, there was talk of blunting the silverback's
teeth, an idea no one liked.
"We finally decided, after watching what was going on, that it really
wasn't Kwisha's fault," Ms. Petiniot said. Kwisha was just being a
normal dominant male.
"He was trying to approach her, and she would go berserk. He'd walk
up to her, and she'd scream bloody murder and charge him and jump on
By tracking Johari's menstrual cycles against injuries in the gorilla
group, Ms. Petiniot noticed a correlation.
Troupe members were most likely to be injured the week before Johari's menses.
Johari was given daily doses of an antidepressant often used for
premenstrual tension. A month after she started on Prozac, she was
reintroduced to her group. To everyone's delight, the reintroduction
"They were fine. I don't think we had any injuries," Ms. Petiniot said.
In fact, Johari and Kwisha bred, and the female gave birth to Dara in
August, 2003. The zoo staff hoped the hormonal changes of pregnancy
and nursing would reduce her premenstrual symptoms. Antidepressant
treatment was stopped. It proved a mistake.
"She got kind of psychotic on us," Ms. Petiniot said. Johari was back
on antidepressants in a month, and she remains on them.
Ms. Petiniot acknowledges she is conservative when it comes to the
use of any drug. She'd rather have the animals living drug-free
whenever possible. But animal behavior expert and veterinarian Kathy
Houpt of Cornell University in Ithaca, N.Y., says real ethical
problems can arise when needed treatment is withheld.
"I think it's unethical to have an animal - for example a dog with
separation anxieties, desperately trying to get out of the house,
digging until his paws are bloody - it's unethical not to treat them
with drugs if it will make them not as anxious or not as aggressive.
You're making an animal feel more contented," Dr. Houpt said.
The emotional lives of great apes seem to demand special
intervention. When any of the gorillas is immobilized for treatment
or surgery, Kwisha becomes completely unglued, Ms. Petiniot said.
"He just gets really upset," she said. His displeasure is compounded
by profuse diarrhea. Kwisha's emotional state, and its unpleasant
side effects, spreads to all the other gorillas. Everyone gets sick.
The male also refuses to take his group outside.
"They're afraid to move. They want to stay where it's safe," Ms. Petiniot said.
Today, Kwisha gets a dose of Valium before any gorilla is sedated for
treatment. Unfortunately, the calm isn't flawless. It does nothing to
stem the nervous diarrhea.
In zoos, increased contentment can mean decreased injuries. When the
Toledo Zoo opened its Africa exhibit in 2004, it used the
antipsychotic medication haloperidol to ease animals into the new,
Haloperidol is used to treat schizophrenia in humans, but it is known
for its severe side effects. Extended use can produce tardive
dyskinesia - involuntary movements of the face, tongue, lips, trunk,
and extremities. The dyskinesia can be permanent. But when Haldol is
used for short periods in animals, it acts as a tranquilizer, zoo
The zoo's four new wildebeests were on Haldol off and on from April,
2004, through December, and they have been put on it at various times
this year as well.
The wildebeests' feisty nature drove the zoo's veterinarian to try
"They're sort of unique in the hoofstock world in how they deal with
the different challenges they face as a herd animal," said Wynona
Shellabarger, the zoo's veterinarian. "They tend to stand and
challenge rather than run away. There's a lot more just general
competition for the alpha spot, the dominant animal."
The animals were continually monitored while on the drugs, she said.
"We were looking for all the potential side effects," but saw none, she said.
The zoo's new Grant's zebras were on haloperidol in November and
December to ease them into new surroundings.
Zebras will chase anything new or unfamiliar in their environment,
said Dr. Shellabarger. When it was time for the zebras to join other
animals in the Africa exhibit, the animals received haloperidol.
"It would be silly to try an introduction without some type of
intervention," Dr. Shellabarger said.
When one of the impalas in the Africa exhibit gave birth, the zebras
were put on haloperidol again.
"Zebra are known to kill baby impala. That's just a natural
behavior," Dr. Shellabarger said. "Something new, something
vulnerable, perhaps they somehow perceive it as a threat."
This time, the zebras were on haloperidol for three days, Dr.
Shellabarger said, blunting their response to the new animal in their
But the antipsychotic failed to work on Maxine, a swamp monkey at
violent odds with a young daughter reaching sexual maturity. Last
year Dr. Shellabarger, Ms. Meyerson, and the zoo's behavioral
specialist agreed to try the drug on Maxine over the objections of
the monkeys' keeper. At first, Haldol made Maxine groggy. But a
reduced dose did not stop her attacks on the youngster. Eventually,
Maxine's daughter was removed from the family group.
Nor did the drug work on a pair of female ostriches.
"It's not a foolproof thing," Dr. Shellabarger said.
A dose of caution
Karen Overall, a veterinarian who specializes in animal behavior at
the University of Pennsylvania, has acted as a consultant to zoos and
animal sanctuaries. While she is an advocate for the use of
antidepressants in animals, including pets, she's more cautious when
it comes to haloperidol.
While antidepressants generally increase the availability of the
neurochemical serotonin, haloperidol works with the brain chemical
dopamine. Dopamine-effecting medicines tend to produce more side
effects, Dr. Overall said.
"I've seen it used in monkeys. I usually get called after it doesn't
work," she said. "I don't like Haldol. I don't like the dopaminergic
drugs, the ticks they produce. It can make some animals more anxious."
She acknowledged Haldol is often used successfully in parrots and
other birds, but she noted that a bird's metabolism is dramatically
different from that of a mammal.
Laurie Bergman, a veterinarian and behavior specialist with the
University of California, Davis, says haloperidol is a drug of last
resort. Dr. Bergman also does consulting work with zoos.
"Something like Haldol, that's in many ways a sloppy drug. You have a
lot of risk of side effects and also overall repression of normal
Haloperidol was effective for the Toledo Zoo's female Birds of
Paradise, Trouble and her sister, Double Trouble, said Robert
Webster, the zoo's bird curator. The females were plucking out
feathers, and no amount of new toys or other interventions put a stop
to the behavior. After three days on Haldol, Trouble stopped
plucking. Double Trouble, who now lives at a Fort Worth zoo, stopped
plucking after a second three-day treatment.
Although there is little published veterinary literature about the
effects of drugs like haloperidol in wild animals, the use of
psychotropic drugs is likely to increase, as zoos look for ways to
keep confined animals as happy and as injury-free as possible.
"It seems to me if people are willing to keep animals in a zoo, they
ought to do anything necessary to make those lives as atraumatic as
possible," Dr. Overall said.
Contact Jenni Laidman at: jenni at theblade.com or 419-724-6507.
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