In 2005 Americans spent over $15 million on behavior-modification drugs for their pets. A cat that was attacking its owner was diagnosed as being deficient in serotonin, the neurotransmitter that provides a feeling of well-being. A dog that chased its tail for up to 5 hours was diagnosed with obsessive-compulsive disorder. Then there's the increasing number of pets being treated with drugs that have the same active ingredient as Prozac. What's next? Maybe we should have holistic centers where pets can be taught to reduce stress by petting their owners.

On the other hand - or paw - some pets take very good care of their owners. Some dogs can differentiate smells and know their owners are sick before they know. Studies have shown that dogs can detect breast and lung cancer. The Pine Street Foundation, a non-profit cancer education and research group, is training dogs to detect ovarian cancer. Other canines have been trained to recognize when diabetics' blood sugar levels drop and for the past 20 years dogs have been used to alert owners of pending seizures. It seems dogs have the ability to be dognosticians.

When Booger, a black pit bull terrier died, his California owner was so grief-stricken she sold her house to raise the $50,000 needed for RNL Bio. RNL is a biotech company affiliated with the South Korean lab that produced the world's first cloned dog. RNL scientists used skin cells taken from Booger's ear before he died to make embryos. The embryos were later implanted in two surrogate dogs. Two months after that the now-houseless Ms. McKinney had five, black pit bull terrier puppies and may be happily living in a pup tent.

Advances in medicine, however, are not just prolonging the lives of pets. They are enabling zoo animals to live longer too. The National Zoo in Washington, D.C. has 100 geriatric animals - animals that have outlived the lifespan they would have had in the wild. There's a lion with a weight problem, a gorilla with heart disease and exotic birds with hardening of the arteries. Then there's Ambeka, a 60-year-old, female elephant. Elephants have 6 sets of teeth in their lifetime and Ambeka is on her sixth set. It's harder for her to stand up and lie down. Her weight has shifted and she moves slower. Because older humans can identify with Ambeka's age-related problems, maybe older elephants actually do forget.