What happens when a zoo animal gets depressed?

[Guest guest]

The Tears of a Panda

What happens when a zoo animal gets depressed?

http://www.slate.com/id/2149682

By Engber

Posted Thursday, Sept. 14, 2006, at 6:28 PM ET

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A sleep-deprived panda inadvertently crushed her newborn cub to

death at a zoo in China last week. " Pandas who lose their young tend

to be depressed for a month or so, " said a zoo official. " Yaya

appeared to be so sad when she couldn't find her baby. … Tears could

be seen in her eyes. " What happens when a zoo animal gets depressed?

It gets special treats or psychiatric treatment. Keepers can tell

something's wrong when an animal becomes lethargic and unresponsive

or stops eating its food. Other warning signs include excessive

grooming (like picking fur or plucking feathers), rocking in place,

and pacing in circles. Zoo employees must first rule out physical

ailments that could cause similar symptoms. An animal with an ulcer

or a broken finger, for example, might mope around in the corner

because it's in pain. A skin condition might elicit a grooming

response that looks something like OCD.

A sad-sack animal can sometimes be coaxed out of a funk

with " enrichment items " like toys and special foods. The pandas at

the National Zoo get " fruitsicles " —apple-juice-flavored ices with

embedded pieces of fruit. A blue period may also pass on its own,

given enough time.

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Some zoo veterinarians prescribe antidepressants as a last resort.

Last year, the Toledo Zoo admitted that it had been running an

extensive psychiatric program: One gorilla took Prozac for anxiety

that seemed to be associated with her menstrual cycle, zebras and

wildebeests were given the antipsychotic Haldol to relax in a new

environment, and an agitated tiger was dosed with Valium.

It's not clear how well these drugs work for exotic animals—there

aren't many placebo-controlled studies of antidepressant use in

gorillas, zebras, and tigers. We've got more information on dogs and

cats: Both SSRI-class drugs (like Prozac) and tricyclics (like

Anafranil) seem to work. Researchers assess a pet's anxiety by

counting anxious behaviors, like the number of times it urinates in

a stressful situation.

When veterinarians dole out antidepressants, they almost always go

off-label. That means they're prescribing a drug that's only been

approved for human use. (This is perfectly legal.) The Food and Drug

Administration has approved only one antidepressant for animal use—

Clomicalm, which is the same drug as Anafranil. But the approval

extends only to dogs, and only to treat " separation anxiety. "

Studies reveal that training an anxious dog works just as well as

giving it Clomicalm, but it takes a lot longer.

Bonus Explainer: Are antidepressants tested on animals as they're

developed? Yes. Drug companies use animals to check both the safety

and the efficacy of new compounds. Antidepressants are deemed

effective if they extend the amount of time an animal—like a mouse—

is willing to endure unpleasant situations—like swimming in a pool

of water. No one knows if this really corresponds to the

animal's " happiness, " but researchers have found that it correlates

with drug efficacy in humans. As the president of R & D at Wyeth

explained to the New York Times a few years ago, " [W]e don't try to

relate the behavior in an animal to a human behavior. "

Got a question about today's news? Ask the Explainer.

Explainer thanks Bain of the University of California and

Xanten of the National Zoo.