Dog treats known as bully or pizzle sticks may actually have more calories than expected and may also be contaminated by bacteria, according to a new study published in the Canadian Veterinary Journal.
Researchers from Tufts University's Cummings School of Veterinary Medicine studied 26 bully sticks, dog treats made from the uncooked, dried penis of a bull or steer, which were made by different manufacturers. They found that the dog treats contained 9 to 22 calories per inch, an average of 88 calories in the standard 6-inch bully stick. The amount of calories researchers found to be in the treats makes up 30 percent of a 10-pound dog's daily calorie requirement and 9 percent of a 50-pound dog's daily calorie requirement.
"While calorie information isn't currently required on pet treats or most petfoods, these findings reinforce that veterinarians and pet owners need to be aware of pet treats like these bully sticks as a source of calories in a dog's diet," said the study's author Dr. Lisa Freeman, a professor of nutrition at the Cummings School of Veterinary Medicine. "With obesity in pets on the rise, it is important for pet owners to factor in not only their dog's food, but also treats and table food."
In addition, nearly one-third of the bully stick treats examined by researchers were found to be contaminated with bacteria. The type of bacteria found varied: Clostridium difficile was found in one stick, methicillin-resistant Staphylococcus aureus was found in one stick, and E. coli was found in seven sticks.