Canine Cancers on the Increase : Pets: Lymphosarcoma is striking more and more of America’s dogs, and one of the causes may be a common weed killer.

For seven years, “Pepper” Gates romped and played on the lush, professionally treated lawn of her owners’ Ellicott City, Md., home. Then Pepper, a schnauzer, was stricken with lymphosarcoma, a common type of cancer.

Mary Gates began the chemotherapy treatments for her dog at the same time she ended the chemical treatments for her lawn. Pepper’s illness persuaded her to do it.

“We had a lawn-care company for all those years, but when Pepper got sick we stopped it,” says Gates.

After 18 months and nearly $2,000 in veterinarian bills, Pepper’s cancer is in remission and the small black dog appears perfectly healthy. Pepper still plays with children and her favorite knotted-sock toy. Yet Gates knows the outlook is grim, and that the cancer will eventually win. In dogs, it always does.

“The time will come,” she says. “But we’re better prepared for it now.”

Advanced veterinary medicine has bought Pepper some extra time. Yet Gates is convinced the dog’s sickness was preventable.

“I think the (lawn) chemicals had everything to do with the cancer,” she says. “We always thought the lawn treatments were safe.”

Not for man’s best friend, some scientists say. Dogs that play on herbicide-drenched lawns are up to twice as likely to develop lymphosarcoma, according to a recent National Cancer Institute report. The study linked the growth of cancers to the use of the chemical 2,4-D, a common weed killer.

“We’ve long thought that lawn chemicals contributed to cancer in pets,” says Dr. Lisa Fulton, a veterinary oncologist in Gaithersburg, Md., who has treated hundreds of dogs with cancer.

“Dogs don’t wear shoes. They lick their feet. They eat the grass,” says Fulton. “And a lot of pet owners take a laissez-faire attitude because the government has cleared these chemicals.”

Pelleted herbicides seem to present a greater threat to pets than do sprays because they dissipate more slowly, says Fulton.

Clients often question the effect of lawn chemicals on their pets’ illnesses, says Fulton. But there are other environmental factors that probably contribute to tumors in dogs, including exhaust fumes, powerful flea and tick repellents and radiation exposure from the sun.

“A lot of people ask about the effects of passive smoking on pets,” she says. “The fact is, we don’t know what causes most cancers.”

As the life expectancy of dogs increases, so does the risk of cancer in old age, says Fulton.

“But that doesn’t account for the increase in tumors we’re seeing in younger dogs,” she says. “We’re getting a lot of 3- and 4-year-old golden retrievers with lymphosarcomas.”

Fulton has treated even younger dogs. “David” Fishel, a 1 1/2-year-old Great Dane suffering from bone cancer, had his left hind leg amputated below the hip two weeks ago. After two chemotherapy treatments, David was running in the woods behind his home and begging for table scraps.

“I don’t think dogs get neurotic about the loss of a limb,” says Dr. Rhonda Fishel, a Baltimore surgeon who is David’s owner. “His prognosis is poor, but his quality of life is good. He gets ice cream every night before bed.”

Most clients are stunned by their pet’s positive reaction to treatment, says Fulton, Maryland’s only practicing veterinary oncologist.

“They come here very disheartened and dismayed,” she says. “Cancer scares people, even in a pet. Some fall apart at the mention of the word. They think that if the dog needs chemotherapy or radical surgery, its quality of life will be less.”

In fact, unlike humans, dogs seldom react negatively to cancer treatments. One in four will suffer minimal side effects--vomiting and diarrhea for 24 hours--while breeds such as terriers, poodles and sheep dogs may lose their hair.

“The vast majority of them adjust very well,” says Fulton.

“Lady” Harrell, a 7-year-old mixed breed from Beltsville, Md., goes for five-mile walks and will outrace her owner to the car when they go for a ride. Lady was diagnosed 22 months ago with lymphosarcoma, one of the more treatable cancers.

“I don’t think she knows she is sick,” says her owner, Ray Harrell. “She’s done beat the odds.”

Generally, chemotherapy extends a dog’s life for between six months and a year, says Fulton, though some of her patients have lived comfortably for four years.

But cancer treatments for pets are neither cheap nor a cure.

“Most of my patients are terminal when they walk through that door,” says Fulton. “It’s just a matter of when.”

Ray Harrell, whose dog suffered a minor setback two weeks ago, says he has spent nearly $5,000 already to save Lady, a stray he took in as a puppy.

“To me, she’s a life,” he says. “I’ll never give up. She’ll have to give up.”

Five cancerous dogs crossed Fulton’s path one day last week: a cocker spaniel with a brain tumor, two golden retrievers, a mixed breed and a Doberman.

All were deemed treatable except the Doberman, a 6-year-old named “Baby Girl” with an aggressive fibrosarcoma on her head. Baby Girl had to be put to sleep by injection as her owner hugged her tightly.