PillPopping Pets Dogs, Cats, And MoodAltering Drugs NYTimes.com

Corrections Appended

Max retrieves Frisbees. He gobbles jelly beans. He chases deer. He is — and this should be remembered when discussions of cases like his blunder into the thickets of cognitive ethology, normative psychology and intraspecies solipsism — a good dog. A 3-year-old German shepherd, all rangy limbs and skittering paws, he patrols the hardwood floors and wall-to-wall carpets of a cul-de-sac home in Lafayette, Calif., living with Michelle Spring, a nurse, and her husband, Allan, a retired airline pilot. Max fields tennis balls with his dexterous forelegs and can stand on his hindquarters to open the front door. He loves car rides and will leap inside any available auto, even ones belonging to strangers. Housebroken, he did slip up once indoors, but everybody knows that the Turducken Incident simply wasn’t his fault. “He’s agile,” Allan says. “He’s healthy. He’s a good-looking animal.” Michelle adds, “We love him to death.” That is why they had no choice, she says. The dog simply had to go on psychoactive drugs.

I arrived the night Max was to receive his first pill. He picked at the food in his chow bowl while the Springs sat at the kitchen table discussing his problems. For starters, there was his overpowering need to be near people, especially Allan. If they put Max outside, he quickly relieved himself and then rushed back indoors; he raced into rooms that Allan was about to occupy; he rested his head against the bathroom door during his master’s ablutions. “Watch this,” Allan said. He and Michelle stood up to hug. The moment they touched, Max unleashed a string of high-pitched barks. “He likes being close to us, but he doesn’t like us being close to each other,” Allan said.

These behaviors, however, weren’t what prompted the psychiatric intervention. The Springs led me downstairs to the family room — Max, supper unfinished, bounded ahead. Downstairs, Allan pointed to Max, who was lying on the floor and staring at his tail. He looked angry at it, disturbed by it. “You can see the pressure building in his psyche until he’s ready to explode,” Michelle said. And then he did: Max jumped to his feet and lunged. His jaws snapped, catching only air, and he spun counterclockwise in place, an accelerating blur of fur and teeth and frustration. Tail-chasing is normal — except that Max did it daily, often for hours on end. “He’s like a junkie needing a fix,” Allan said. “At times he can’t not do it. He goes berserk.”

Allan went upstairs and returned moments later with a bit of ground turkey and a pill. He hid the pill in the meat and extended his hand to Max, who had stopped spinning. The medicine was chemically identical to clomipramine, a tricyclic antidepressant used in human psychiatric care, but it came in a green-and-white Novartis box brightened by the picture of a happy yellow lab. This wasn’t Anafranil, the brand name for the human version of the drug; it was Clomicalm, just for dogs. Approved by the Food and Drug Administration for treating separation anxiety, a problem that can occur when dogs are left home alone, the medication is also commonly prescribed off-label for patients with Max’s diagnosis: compulsive disorder. He was the canine version of a person who washes his hands 20 times an hour. Max leaned forward and gulped the pill down.

The practice of prescribing medications designed for humans to animals has grown substantially over the past decade and a half, and pharmaceutical companies have recently begun experimenting with a more direct strategy: marketing behavior-modification and “lifestyle” drugs specifically for pets. America’s animals, it seems, have very American health problems. More than 20 percent of our dogs are overweight; Pfizer’s Slentrol was approved by the F.D.A. last year as the country’s first canine anti-obesity medication. Dogs live 13 years on average, considerably longer than they did in the past; Pfizer’s Anipryl treats cognitive dysfunction so that absent-minded pets can remember the location of the supper bowl or doggy door. For lonely dogs with separation anxiety, Eli Lilly brought to market its own drug Reconcile last year. The only difference between it and Prozac is that Reconcile is chewable and tastes like beef.

Doggy diet pills may be plainly absurd, but scientists in an expanding field known as behavioral pharmacology say that the combination of new drug therapies and progressive training techniques can solve problems that in the past almost always resulted in euthanasia. The supposed effectiveness of psychiatric medicines in treating mood and behavior issues is prompting new questions in the centuries-old debate over what, exactly, separates mankind from the beasts. If the strict Cartesian view were true — that animals are essentially flesh-and-blood automatons, lacking anything resembling human emotion, memory and consciousness — then why do animals develop mental illnesses that eerily resemble human ones and that respond to the same medications? What can behavioral pharmacology teach us about animal minds and, ultimately, our own?

ON SEPT. 5, 1379, A TRIO OF French pigs, agitated by the squealing of a piglet, bowled over their keeper’s son, who died shortly thereafter of the injuries. As E. P. Evans recounts in his 1906 monograph, “The Criminal Prosecution and Capital Punishment of Animals,” “the three sows, after due process of law, were condemned to death” along with several other pigs who had “hastened to the scene of the murder and by their cries and aggressive actions showed that they approved of the assault.” (The accomplices were later pardoned.) Fast-forward to December 2007 to witness a curious animal proceeding of the modern era: Mitzi-Bitzi, a lap dog, modeling a 8,000 diamond bracelet at the opening of Chateau Poochie, a pet hotel and spa near Miami. “She’s just so special,” her owner, Marilyn Belkin, told me later, as if that explained things. The sows and Mitzi got opposite treatment, but the beliefs of Belkin and the pig prosecutors weren’t so different. In medieval times and in the present, we often act as if animals had thoughts, feelings and desires that resemble those of people. How else could you justify the porcine death penalty; why splurge on a blueberry facial when a simple roll on the lawn would do?

Marketers have a new name for the age-old tendency to view animals as furry versions of ourselves: “humanization,” a trend that is fueling the explosive growth of the pet industry and the rise of modern pet pharma. Americans forked over billion for pet products and services last year, up .5 billion from 2003; other than consumer electronics, pet products are the fastest-growing retail segment. The market expansion is being driven both by more pets and by more spending per pet, especially by affluent baby boomers whose children have graduated from college. A third of the total spending, and the fastest-growing category, is health care, with treatments formerly reserved for people — root canals, chemotherapy, liposuction, mood pills — being administered to pets. “I get asked all the time, ‘What is it with this humanization — do we suddenly love our pets a whole lot more?’ ” says David Lummis, who analyzes the pet industry for the market research firm Packaged Facts. “My theory is that it’s always been there, but it’s been sanctioned now. It’s not just the crazy cat lady. It’s marketers and all of this consumer advertising that have made it O.K. to spend tons of money on your pet.”

James Vlahos writes for National Geographic Adventure, Popular Science and Popular Mechanics. This is his first article for the magazine.

This article has been revised to reflect the following correction:

Correction: July 12, 2008 The cover article this weekend about the expanding market for mood-altering drugs for cats and dogs misstates the revenues Pfizer Animal Health has earned from animal medications. The total for this division, which includes livestock, is .6 billion, not “nearly billion.” Its “companion animals,” or pet division, contributed nearly billion to this total.

This article has been revised to reflect the following correction:

Correction: July 13, 2008 The cover article this weekend about the expanding market for mood-altering drugs for cats and dogs misstates the revenues Pfizer Animal Health has earned from animal medications. The total for this division, which includes livestock, is .6 billion, not “nearly billion.” Its “companion animals,” or pet division, contributed nearly billion to this total.