Tuesday, Oct 16, 2018
One of America's Great Newspapers ~ Toledo, Ohio

Zoos using drugs to help manage anxious animals

  • Zoos-using-drugs-to-help-manage-anxious-animals

    Char Petiniot, in front of the gorilla enclosure at the Toledo Zoo, has used Prozac and Valium on gorillas.

  • Zoos-using-drugs-to-help-manage-anxious-animals-2

    Robert Webster, the Toledo Zoo's bird curator, says Haldol helped keep two of his birds from plucking their feathers out. Nothing else the zoo had tried seemed to work as well.


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 group.

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 denizens.

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.

Long-term treatment

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 female gorilla.

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 with Kwisha.

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 him.

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 was trouble-free.

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.

Ethical issues

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.


Robert Webster, the Toledo Zoo's bird curator, says Haldol helped keep two of his birds from plucking their feathers out. Nothing else the zoo had tried seemed to work as well.


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, mixed-species exhibit.

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 staffers say.

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 drug intervention.

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 environment.

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 behavior.

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@theblade.com or 419-724-6507.

Click to comment

Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem?

Temporibus autem quibusdam et aut officiis debitis aut rerum necessitatibus saepe eveniet.

Copyright © 2018 Toledo Blade

To Top

Fetching stories…