I guess so, at least that's what wiki and Merriam's both say. Hmmm, I hadn't fully read the email alert about the chews which the FDA sent me. I decided to go ahead and include it even though it's not a part of the big recall of wheat gluten since it does potentially affect people.
Wikipedia:
Bull pizzles are almost exclusively used/produced today as chewing treats for dogs.[citation needed] The pizzles of bulls are cleaned, stretched, twisted and then dried at a very high heat. The result is a very hard, 80-100 cm long brown stick, which is then sawed into pieces appropriate for the size of the dog, usually 10-20 cm (this process also makes its anatomical origin rather unrecognizable).
The fully digestible bull pizzles are excellent chewing toys. Since they consist mostly of proteins, they can usually be ignored for the daily calorie intake of the dog.[citation needed] As is the case for most chewing toys, the dog will clean its teeth by itself during the lengthy chewing process. However, most humans find the smell of a half-chewed bull pizzle rather unpleasant,[citation needed] which is probably the reason why synthetic digestible chewing toys have become increasingly popular and displaced the dried bull pizzle into a niche for dog owners who prefer more natural or organic food for their dogs.[citation needed]
Unpleasant thought for the day!