By Dr. Becker
According to a recent study1 jointly conducted by Tufts University’s Cummings School of Veterinary Medicine and the University of Guelph (Canada), the popular dog treat known as “bully sticks” or “pizzle sticks” may be higher in calories than pet owners realize, and may also be contaminated with bacteria.
The researchers evaluated both the calorie content and bacterial contamination levels of the treats, which are actually made from the uncooked, dried penises of bulls and steers (pizzle is an old English word for penis). The study also included the results of a survey given to pet owners to determine how much they knew about the treats.
Bully Sticks Can Contain Up to 22 Calories PER INCH
For the study, the Tufts and University of Guelph researchers used 26 bully sticks made by different companies and purchased from sellers in the U.S. and Canada.
Study results revealed the bully sticks ranged from 9 to 22 calories per inch, meaning a 6-inch treat could potentially contain a whopping 132 calories. Assuming the average 6-inch stick has 88 calories (about 15 calories per inch, which is midway between 9 and 22 calories), that’s the equivalent of nine percent of the daily calorie requirement for a 50 pound dog.
If your canine companion is considerably smaller, say 10 pounds, one 6-inch bully stick contains 30 percent of the calories he should eat in a day.
If you purchase these treats for your dog and feed them regularly, you’re probably shocked to learn how many calories they can contain. This is especially true if your pet, like so many dogs today, is overweight or obese.
Since there’s no requirement of pet food and pet treat manufacturers to print calorie content on packaging labels, you can see how important it is to do your own research on how many calories you’re actually feeding your pet in a day.
If you’re not sure how many daily calories your pet requires to remain at (or return to) a healthy weight, you can use the formulas provided in my article How to Tell If Your Pet Needs to Shed Some Pounds.
The researchers also tested all 26 bully sticks for bacterial contamination. One treat showed contamination with Clostridium difficile, another was contaminated with MRSA (methicillin-resistant Staphylococcus aureus), and seven sticks showed the presence of E. coli, including one sample that was tetracycline-resistant.
These findings aren’t surprising. Bacterial contamination of meat is a regular occurrence, and additional contamination can occur during packaging, shipping and storage. Your pet’s body was designed to handle an impressive bacterial load from food, although contrary to popular belief, pets can and do get food poisoning if sufficient pathogenic strains of bacteria are consumed. Not all of these bacterial strains have been shown to infect humans, but as always, you should wash your hands after handling any pet food or treat.
I’d be more concerned about the calories in these treats than potential bacterial contamination. If you feed bully sticks to your dog and there’s no calorie content on the package label, I recommend visiting the website if one exists or contacting the manufacturer to get that information. And as with any commercial pet treat, make sure to buy a 100 percent natural product sourced and manufactured in the U.S.
Bull Penis? Who Knew?
The survey used in the study was completed by 852 adults, mostly female dog owners, in 44 states and six countries. Twenty-three percent fed bully sticks to their pets.
According to Dr. Lisa Freeman of Tufts and the lead study author:
"We were surprised at the clear misconceptions pet owners and veterinarians have with pet foods and many of the popular raw animal-product based pet treats currently on the market. For example, 71 percent of people feeding bully sticks to their pets stated they avoid by-products in pet foods, yet bully sticks are, for all intents and purposes, an animal by-product."
The researchers also discovered that a large number of survey respondents didn’t know the origin of bully sticks.