Some owners swear by organic pet chow, but does it do much for animals?

Chris Rossi goes to a nearby corner bakery every week for an assortment of delicacies. But as he moves from the glass display case to the cash register, the savory aroma wafting from behind the counter makes him double back.

The smell is fresh-cooked meat--lamb, liver, turkey--and Rossi is dragged back by his dog, Bongo, pulling on his leash. The 10-month-old cocker spaniel-poodle mix can’t wait to sample the latest naturally prepared treats from Buttercup’s Paw-tisserie.

The store’s owners--equipped with rollers, baking sheets and a large oven--bake treats that are good enough for humans but specially made for dogs. The goodies contain no preservatives or sugar and include brownies filled with meat and cheese, and even “lollipups.”

Thirtysomethings Scott Wong and Betty Wong, who are not related, opened the fido-friendly shop four months ago in a rapidly gentrifying stretch of Brooklyn’s Park Slope neighborhood that includes trendy restaurants, a chocolate maker and designer boutiques.

“This is my best friend, you know, so I've got to hook him up,” said Rossi, 29, as he kneeled on the shop’s floor to pet Bongo’s dark black coat. He had just bought some natural freeze-dried beef.

Whether those delicious treats are healthier for Bongo, though, remains unclear. Health-conscious pet owners like Rossi are increasingly buying organic pet food, hoping the diets will lead to spunkier, longer-living cats and dogs. But there is no reliable scientific research to back up the perceived benefits.

“There’s just a lot more to know,” said Dr. Narda Robinson, who teaches veterinary medicine at Colorado State University. Customers can be seduced by nutrition-promising package labels, she said, but the real benefits of organic pet food won’t be known until more extensive studies are done.

The U.S. Agriculture Department, which regulates organic farming and package labeling, is more blunt. The agency's organic pet food task force says organic products hold no nutritional advantages over conventionally produced food.

“Organic foods of any kind, for people or animals, are not more healthful,” said Nancy Cook, the task force's chair, in an e-mail message. “They are just produced using different processes.”

Indeed, the term “organic” is in some ways a buzz word that buyers translate to mean more nutritious. In fact, it simply refers to the strict guidelines farmers must follow, like not giving livestock antibiotics or growth hormones and making sure crops are free of conventional pesticides and fertilizers.

In some cases, an organic or natural diet could actually be worse for animals. An organic raw food diet, for example, might contain bacteria that could make a pet seriously ill, said Robinson, the veterinarian.

That concern prompted the Paw-tisserie owners to consult an array of veterinarians and other research. “Dogs supposedly have the kind of immune system that can fight that bacteria,” Scott Wong said, referring to the contents of the raw foods they sell.

But those appear to be fleeting considerations to an organic pet food industry on the march. Such food remains a small share of the pet food market--just under 1 percent--but sales data suggest a steady surge lies ahead as pet owners clamor for posh pet diets.

Organic pet food sales increased nearly two-thirds to $14 million in 2003 from the year before, according to the most recent data from the Organic Trade Association, an industry group that tracks food sales. The same research predicted a 17 percent sales spike each year between 2004 and 2008.

“Ten to 15 years after the trend appears in humans, you start to see it expand into the pet neck of the woods,” said Robert Vetre, managing director of the American Pet Products Manufacturing Association.

Several companies now offer expensive alternatives to generic pet food. Newman’s Own Organics, the food company started by actor Paul Newman’s daughter, Nell, sells a 25-pound bag of organic dog food for $39.99. The same price nets 30 pounds of another organic pet food brand called Nature’s Variety, which promises natural and nutritious ingredients.

The cost can be twice that of regular pet food. A comparable amount of Pedigree dog food, for example, goes for $13.99. But owners say they get what they pay for.

Chelsea Albucher spends about $40 a month on natural food for her 4-year-old Boston terrier, Buddha. Her first terrier, named Oreo, died of a brain tumor, which she attributed partly to his diet.

The 34-year-old Brooklyn resident stopped at the Paw-tisserie one morning for liver biscotti. She jingled the treats-filled bag at Buddha, who wore a bright green sweater, and promised him his craving would soon be fulfilled.

“It has very few additives and fillers,” Albucher said of organic pet food. “It’s very straight-forward.”

But examining the ingredients in a purported organic pet food bag can get confusing. The food often contains a combination of organic and natural ingredients. Newman’s pet food, for instance, is only about 70 percent organic. The remaining ingredients, though not produced through certified organic processes, remain free of steroids, corn and artificial additives.

Still, technicalities are unlikely to curb the demand for high-class pet cuisine. Vetre, the pet products association director, recently scanned a list of more than 700 products at the Global Pet Expo in San Diego and estimated that about 25 percent had an organic component.

That’s good news for Rossi, who said his dog loves weekly freeze-dried beef helpings from the Paw-tisserie.

“He seems to be just a lot more energetic with that kind of food,” said Rossi, as he watched an unleashed Bongo scamper around the shop. “I think it’s much better for them.”

E-mail: mds2133@columbia.edu