A zoo advocacy group is calling for an investigation into the cause of a half-dozen puncture wounds on the head and face of an elephant that injured a veterinarian who was trying to treat the wounds. ``What we're talking about here is abuse,'' Sandra Keller, spokeswoman for Citizens for a Better Zoo, said Sunday. ``We have been receiving complaints about the way these elephants are being mistreated for several months.'' Veterinarian Gail Hedberg was treating an abscess on the head of a 3{-ton Asian elephant named Tinkerbelle when the animal attacked her Saturday, fracturing her pelvis. Zookeepers said Tinkerbelle did a ``handstand'' on the woman. Hedberg was listed in stable condition today at San Francisco General Hospital. Some officials defended practices at the San Francisco Zoo. ``We have to use elephant hooks and other methods that may appear abusive because we're not talking about puppy dogs and pussy cats here,'' said zoo director Saul Kitchener. ``How do you get a 10,000-pound elephant's attention?'' Elephant keeper Michele Radovsky said beating an elephant is no different from ``people taking rolled newspapers and hitting their dog.'' But Paul Hunter, a keeper at the zoo for nine years, said the abscess on Tinkerbell's head was caused by someone hitting her too hard with a hooked instrument called an ankuf or elephant hook. ``The elephants get beaten up real bad, and I'm getting tired of it,'' said Hunter.