Dog owners who make sure their pets eat right and exercise may be unknowingly feeding their pets ground animal parts, including crushed bird beaks and brains, and possibly making them sick, according to a Local 6 News investigation.

The report said that the government agency that oversees pet food sold to the public -- the Food and Drug Administration -- said it is perfectly legal to include animal parts in pets' diets.

"It could be anything from heads, feet, intestines and undigested eggs," veterinary nutritionist Dr. Edward Moser said.

"Experts admit the labels (on pet foods) are not that graphic," Local 6's Mike Holfeld said. "The companies use terms like animal or poultry by-products and not brains or crushed beaks."

Central Floridian John Pavano said he was not aware he was buying pet food with the animal parts in it for his dogs.

"Did you know (the ingredients)?" Holfeld asked.

"I never knew that," Pavano said. "I never even looked at the labels. I think that is kind of gross. Actually, I can't believe they let dogs eat that stuff."

The report featured Mary Herbert, who lived near a major dog food plant.

"I'd be going by the dog food company and see the trucks -- stinking, rotten stuff -- taking it to the dog food company so I never did believe it was better for the dogs to eat that stuff," Herbert said.

The co-owners of Baldwin Bark and Meow Supply, Connie Matthews and her daughter Ashley Liguori, used to sell pet food brands with animal parts included in the ingredient list. However, now they are checking the labels.

"Owners come in here and they have sick animals and they don't know why," Liguori said. "It is what they are feeding their dogs every day."

"And do you find that is a common problem, that people just don't read the label?" Holfeld asked.

"Absolutely," Liguori said.

The products sold at the store are part of a parallel industry offering higher quality holistic foods as alternatives to the brands Americans have turned to for decades, the report said.

"The first three ingredients are your main ingredients," Liguori said. "You want to make sure that there are good sources of protein in the beginning. No by-products. Again, you want to look for that."

"You are telling me that the names we trust, many of them have these beaks, feathers and animal parts?" Holfeld said.

"Yes," Liguori said.

"And it is happening right now?" Holfeld asked.

"Yes," Liguori said.

The term animal by-product on the back of pet food means it is not fit for human consumption, Holfeld said.

"The healthy pet foods being marketed today will cost more but as one pet store owner suggested, you can pay more for the food now or face expensive visits to the vet later."

Watch Local 6 News for more on this story.