The advertisement in the New Jersey newspaper caught Rosa D'Ascoli's attention: dogs for sale from "professional breeders," $99 and up, all shots included, training provided.

D'Ascoli was anxious to adopt a German Shepherd; she had one as a young girl, and she thought the typically loyal, intelligent and friendly breed would be a good fit for her and her father, with whom she lives in a suburban house in Maplewood, New Jersey. On Saturday, September 8, 2000, D'Ascoli and two friends piled into a car and made the 30-minute trip to the advertised pet store in north central Jersey. An employee ushered them into a little cubicle filled with toys and dog chews.

That's where D'Ascoli first met Gizmo, an eight-week-old male purebred German Shepherd. D'Ascoli already had the name in mind because a German Shepherd's oversized ears always reminded her of the exotic critter, Gizmo, in the 1984 film, Gremlins. This canine Gizmo even had a similar temperament: In the cubicle, the puppy was alert and energetic. "He was playing with everyone," D'Ascoli recalls.

Buying the dog was almost too easy. Pet store employees asked her only one question—had she previously owned a German Shepherd?—before they ran a credit check and had her sign a contract. The paper guaranteed that the store would replace the dog if it died from parvo virus, hepatitis, leptospirosis or corona virus, diseases that are covered by annual shots. The contract also stipulated, "All vet bills will be the responsibility of the purchaser."

Nineteen hundred dollars later, the price tag for Gizmo, Rose D'Ascoli had herself a new companion. As a final send-off, an employee said, "Remember that 95% of puppies may develop the sniffles."

Six days later, Gizmo had the sniffles. But he had more than that: He had a fever, mucus running from his nose, and had lost his appetite. The next day, D'Ascoli took Gizmo to the veterinarian who diagnosed the dog with "kennel cough," which had probably developed into pneumonia. Gizmo's temperature was 102.4. Kennel cough is a common malady among dogs, who usually overcome it quickly, but the veterinarian noted Gizmo's dry coat and his underweight condition, signs that the dog may have come from a mass-breeding facility known as a puppy mill. The veterinarian gave Gizmo a shot and some drops, and told D'Ascoli that her dog should feel better in a few days.

He didn't. In fact, Gizmo didn't start feeling better until nearly two weeks later, after two more vet visits and $300 in expenses. But the troubles were just beginning for D'Ascoli and Gizmo.

The dog demonstrated signs of poor socialization. He became very aggressive toward strangers. Unless Gizmo knew the person, D'Ascoli remembers, the dog "wanted to eat them alive." He also lunged for cars on busy streets when he and D'Ascoli went on walks. So Gizmo went into training, which can help to increase an animal's confidence if he's fearful or unsure around people. D'Ascoli worked patiently with her pooch, but Gizmo inexplicably became timid. Now on his walks, he would crouch down and try to flee traffic.

D'Ascoli worked with Gizmo every day for nearly three months, and by May 2001, he had shown some signs of improvement. Then on May 24, D'Ascoli noticed that Gizmo was making noises while eating, as if he were choking. She felt the dog's throat and spotted a small lump, about the size of a pea. She took him to the veterinarian who couldn't pinpoint the problem. Gizmo went home with antibiotics for an apparent infection.

A few days later, the lump had increased in size, to the point where it was now visible on Gizmo's neck. But since it was the Memorial Day holiday, D'Ascoli had to wait until Tuesday, May 29, to take Gizmo back to the veterinarian, who suggested the dog immediately visit a specialist.

That same day, the specialist told D'Ascoli that Gizmo would need to be sedated and x-rayed to determine the cause of the lump. Then, mostly likely, the dog would require surgery to remove the foreign mass in his neck. D'Ascoli stayed with Gizmo until the anesthesia took effect and then left her dog with the specialist. It was a simple procedure, the specialist promised.

At 4 p.m. on May 29, the specialist called D'Ascoli and said there had been "complications" during surgery. Gizmo's heart had stopped—permanently. The specialist was at a loss herself to explain how the dog died; the only new information the veterinarian could offer was that Gizmo had a large sac of pus in his neck.

It made D'Ascoli recall what the original veterinarian said on Gizmo's first visit back in September: The dog might have come from a puppy mill. She wasn't sure there was a connection, but she still "was devastated." "I actually started taking karate to deal with the anger," she recalls.

Searching for answers, D'Ascoli halted a planned cremation and took Gizmo's body to the University of Pennsylvania for an autopsy. Unfortunately, the dog's body had deteriorated too much by then, and the autopsy results were inconclusive, again leaving D'Ascoli in the dark.

The only remedy D'Ascoli had left to relieve her pain was revenge. She wanted to warn others about the dangers of pet stores, which often buy their "inventory" from mass dog-breeding facilities known as puppy mills. "I wish I could close down every puppy mill that exists," says D'Ascoli, who spent nearly $3,000 on Gizmo and his treatments. "If by telling my story I influence just one person (not to buy from a pet store), I have done justice to Gizmo's short life."

D'Ascoli eventually learned that Gizmo came from an unlicensed breeder based in Iowa, considered one of the seven worst puppy-mill states in the country. But that information alone didn't offer any solace. The U.S. Department of Agriculture, which enforces the Animal Welfare Act, only regulates commercial breeding operations. And even then, the agency establishes only minimum-care standards, such as daily food, water and shelter. Those loose federal standards leave a lot of wiggle room for the kinds of conditions that breed sickly dogs like Gizmo.

So how's a poor consumer to cope in such a dog market? Get the facts on puppy mills and pet stores. Which you can do in the links below.