By C.C. Holland
With the third twist of the vise handle, the bone held snugly inside splintered along its length with a sickening crunch. Splinters and fragments sprouted from the crack like thistle.
The scene of a gruesome torture chamber? Hardly. Rather, this was a common result during informal testing conducted by WDJ in an attempt to ascertain whether certain types of โrecreationalโ bones pose more hazards than others to the dogs who chew them.
First, some background. Our plan was to create a companion piece to an article about rawhide chews that ran in our May 2002 issue. We decided to take a look at the wide variety of commercially prepared bones available to dog owners in pet supply stores and catalogs. We hoped to learn whether these bones originated from U.S. livestock (which tends to be better safeguarded and regulated than animal products from some foreign sources) and what sorts of chemicals โ if any โ were commonly used in the preparation or preservation of the products. On both these counts, we heard good news.
Production methods
All the manufacturers whose representatives were willing to be interviewed told us that their companies obtain raw products from American slaughterhouses, and some (such as Abbyland Foods) get bones from their own slaughtering plants. Bones either were received frozen and thawed for processing or were processed fresh.
Production techniques were similar among the four companies whose representatives we interviewed, including Merrick Pet Foods in Texas; Redbarn in California; Abbyland Foods in Wisconsin; MI Industries (Natureโs Variety) in Nebraska; and Jones Natural Chews in Illinois. (Gimborn Pet Specialties in Atlanta, which sells bones through the Petsmart chain, declined our requests for an interview.) In all cases, creating the final product pretty much consists of simply cleaning and drying the bones in industrial ovens.
Some companies go the extra mile to ensure a quality product. Natureโs Variety โ the only one of these companies that also sells frozen raw bones โ prides itself on strict adherence to food-safety guidelines.
โWe work in very close cooperation with the University of Nebraska food processing center,โ says company president Bob Milligan. โThey help us with processing techniques, selecting oven temperatures, testing for bacteria, and upgrading sanitation methods, things like that.โ
Creating the cooked bones is a no-frills process. โWe slow-roast them and then dry them down to a moisture content of approximately 10 to 12 percent,โ says Milligan. โThat allows them to be shelf-stable without having to add any preservatives, chemicals, or artificial colors. Our opinion, and that of our nutritionists and vets we work with, is that the product doesnโt need to have a smoked flavor to be appealing to the dog. And many times smoking is used to cover up an โoffโ odor or condition.โ
Other companies choose to add flavoring to the bones, either for marketing appeal or, in some cases, to prevent mold.
โWe dip them in a solution of liquid smoke, for smell, and a marinate solution that helps inhibit mold growth,โ says Jane Langman of Abbyland, which sells bones through Drs. Foster & Smith. โItโs an all-natural product โ there are no preservatives.โ
Most of these recreational bone manufacturers say preservatives are not necessary for bone products.
โTypically, with products under 10 percent moisture, thereโs no need for preservatives,โ explains Garth Merrick, president of Merrick Pet Foods. โLack of moisture means a lack of protein to degenerate to the point where you get bacteria.โ
But that doesnโt mean every finished product is immune. All it takes is the right conditions โ such as damaged wrapping and humid weather. Weโve seen shrink-wrapped meaty bones (not produced by any of the companies listed here) laced with mold on the shelves of a local Trader Joeโs grocery store. Once moisture content rises inside the packaging, green fuzz can sprout.
โAlso, where thereโs enough moisture for mold to grow, you can have elevated bacteria levels,โ adds Milligan. โYou can have concerns about salmonella and E.coli.โ
These issues are more likely to affect consumers and their food-handling practices, since healthy, adult dogs are usually unaffected by bugs that would lay humans low. Hand-washing is always recommended after touching a dogโs chew bones.
Well-dried bones in a dry environment can last a very long time on a shelf or in your pantry, which explains part of their appeal. Some owners trade weekly trips to the butcher shop for a box of dried bones. Others donโt have access to butcher shops, but can get dried or cooked bones from local pet stores.
Laura Herr of Jones Natural Chews said her company labels its products with sell-by dates, but itโs more to give the distributor, retailer, or consumer a benchmark than to warn against spoilage. โThey have a very long shelf life,โ she says. โWe put our (sell-by dates) two years out. But weโve had some bones in our testing area for eight years, and they still look beautiful.โ
Additives?
By reducing the moisture content of their products, most of these companies are able to forego the use of preservatives to keep the animal-based products from decomposing. An exception is Redbarn, which uses preservatives in its โstuffedโ bones, which have artificially flavored and colored filling. The stuffing is either cheese-and-bacon, chicken, beef, or lamb flavored.
Jeff Baikie, co-president of Redbarn, defends the filling, which is mostly meat by-products with meat or poultry meal and lots of sugars, salt, and other flavor enhancers, on the basis that itโs meant as an occasional treat. โIโm not saying youโd want to feed this as a full diet, but two ounces once a week isnโt a big deal,โ Baikie says.
Stuffing a bone creates added value for the consumer, Baikie told us, because a dog will remain interested in it much longer. And the processing of the bones Redbarn uses โ stuffed or not โ is minimal, he says; they are simply cleaned and dried.
At WDJ, weโre not wild about these filled bones. For one thing, with so many all-natural, unpreserved, and uncolored treats available today, we think owners can afford to be choosier about their dogsโ treats. Filling aside, weโre even more concerned about the bones themselves.
Dental dangers
There are two main knocks on dogs chewing bones: dental and gastrointestinal concerns.
Frank J.M. Verstraete, DVM, a diplomate of the American Veterinary Dental College and a professor of dentistry and oral surgery at the University of California, Davis School of Veterinary Medicine, agreed to evaluate a variety of cooked treat bones with regard to dental health. We brought him a bag full of commercial recreational chew bones to examine โ roasted, smoked, dried, meat-on, hollow, stuffed, and so on. From his perspective, he says, none are safe for canine consumption.
โBasically, the main rule that we use is that you should be able to make an impression in the item with your thumbnail,โ he says. โIf you cannot, itโs too hard.โ All the bones in our bag flunked his test.
Dr. Verstraete explains that hard, dried bones present an opportunity for dogs to crack premolars while gnawing. (There are four premolars on each side of the upper and lower jaws, directly behind the canine teeth.) Fresh, raw bones are preferable, but once they dry out they also pose a problem. In fact, on the day we interviewed him, heโd treated two dogs โ both described by their owners as non-aggressive chewers โ who had broken teeth on desiccated raw bones.
Natureโs Variety uses a slow-roasting process they say makes the cooked bone less brittle and hard. According to company president Bob Milligan, the final products have a moisture content of about 10 to 12 percent. โIt probably is softer and contains more moisture at the time of manufacturing,โ allowed Dr. Verstraete when he looked over some Natureโs Variety bones. โBut once this has been on a shelf for a while, itโs too dry.โ
Whether certain types of bones โ say, ribs or bones from younger animals โ tend to be safer is an open question. Dr. Verstraete says all evidence either way is purely anecdotal. But the extra-hard bones sometimes designated as appropriate for โaggressive chewersโ? Steer clear. โMuch too hard,โ he says. โGood for a hyena, but not for a dog.โ
While he is very critical of cooked and dried bones, Dr. Verstraete doesnโt go so far as to proscribe bones entirely, especially if a dog has been brought up on bones and uses them regularly for recreational chewing.
โAs long as itโs a fresh bone, and an appropriate size and shape for the dog,โ he says, letting your dog chew is fine. Dr. Verstraete recommends condyles (the lumpy knobs at the end of bones) over the tubular, middle portions of leg bones, because they are softer. Those leg bones are cortical bones, which have a high resistance to bending and torsion.
Cathy Dyer, DVM, a colleague of Dr. Verstraeteโs at UC Davis, says the size of the bone is also very important. โFor those people who really want to give their dog a bone โ because letโs face it, it does really clean the teeth โ Iโve always said give a great big bone, like a beef knuckle bone,โ she says. The idea is to provide a bone thatโs too large for a dog to get between his jaws and bear down, which could lead to tooth damage.
Splinters
In addition to posing dental dangers, bones can also do something else: splinter. The reality is that virtually any bone, cooked or not, can splinter or break in the right circumstances. However, the manufacturers we spoke with said complaints about splintering were virtually nil.
Bob Milligan of Natureโs Variety says the secret to safer bones lies in the selection. โWe try to select bones like the ham bone, which is the main femur bone of the pig,โ he explains. โThat is a medium hardness bone, either in the raw or roasted state. We found that the slow roasting helps soften that bone so splintering has not been a problem. We sell literally hundreds of thousands of those bones and have not had problems. I should add we always caution the pet caregiver to supervise the pet with bones, whether the bones are raw or slow-roasted.โ
Jeff Baikie of Redbarn says his company has fielded โa fewโ complaints. โAny manufacturer who tells you different is probably lying,โ he says. โBut itโs very, very limited. What youโre worried about is splintering, and splinters getting lodged in the dogโs throat or intestines. But for the number of bones we sell, we might get three complaints a year, and weโre talking million and millions of bones.โ
Then again, some said they were aware of problems with certain types of bones. โWe have had requests from some customers to make a sterilized bone; they want it boiled, free of meat,โ says Milligan, adding that Natureโs Variety does not make such a bone. โThe problem we had, and why we did not pursue it, is the bones became very brittle, almost like glass. You could literally drop them and they would break or crack.โ
Breaking bones
That was certainly our own experience in our informal test lab โ the backyard of the editorial office of WDJ. Just for kicks, we decided to subject a wide range of commercial bones and some plain old โbutcher bonesโ to some admittedly unscientific tests, to compare how the different products responded to various physical pressures. We included raw frozen bones, raw thawed bones, and a number of commercially prepared bones, including those with attached meat and tissues, sterilized bones, slow-roasted bones, joints, long bones, and even rib bones. Some of these commercial products were from the companies whose representatives we interviewed, while others were either not labeled or were competing brands.
While we did not attempt to exactly simulate the forces applied by a dogโs teeth and jaws, we did subject each of them to a couple of light taps with a hammer, as well as a brief session of squeezing in a large iron vise. What we found was disheartening.
Every bone yielded to our tests โ some even shattered like porcelain, leaving behind razor-sharp shards, and others resisted several whacks and/or turns of the vise before cracking. The raw bones were marginally softer, as was a ham bone from Natureโs Variety; these cracked and flaked apart. Still, they yielded small pieces. If ingested, what havoc could these splinters wreak on a dogโs mouth, throat, or stomach?
In the vise test, we wanted to approximate the pressure caused by a dogโs jaws closing down on a bone. Once again our test bones gave way โ although the Natureโs Variety dry-roasted ham bone (which included condyles) did best, changing shape but not splitting or breaking.
When the bones cracked in the vise, they splintered. Some, like Smokehouseโs roasted rib bone, lost small, crumbly chunks; others, like Redbarnโs plain white bone, split up their length and fell apart. Even the moist raw bones split off sharp shards.
At the end of our experiment, sitting amid the rubble of broken bones and needle-sharp shards, we had some decisions to make.
We decided that it would be courting danger to recommend giving any cooked treat bones to a dog with large, strong jaws and an aggressive chewing style. Any of the offerings could be reduced to a pile of potentially harmful pieces or could cause a broken tooth.
For moderate chewers or small dogs, we could see giving them an extra-large bone โ one that they couldnโt fit between their back teeth โ and keeping a watchful eye on their activity.
Garth Merrick responded to our concerns by acknowledging that dangers do exist.
โThereโs no question, if you break one itโs going to have some sharp edges,โ he says. โIf the customer will use common sense, I really think the amount of risk is minimized.โ
Proper sizing, he says, is most crucial.
โIf the people who buy the bones will size the bone to the size of the dogโs jaws and keep it big enough so they cannot fit it in and bear down with their back teeth, they cannot put enough pressure on it to break it,โ he says. โEven though there is a risk, there are millions of satisfied people whose dogs have never had a problem.โ
Laura Herr of Jones Natural Chews agreed that owner supervision and sizing were important, but also took it a step further, noting that certain types of bones are less prone to problems.
โThere are several bones that do not splinter,โ she says. โIf you put a shank bone or a knee cap from the knee joint to your test, neither of these bones will splinter even for the most aggressive chewer. Any knuckle bone does not present danger of splinters. The bones that do splinter for the aggressive chewer are the straight bones, which we call center bones.โ
Should you avoid bones entirely? Thereโs no easy answer, and itโs an individual decision. Some dogs will do fine on just about any sort of bone, while others will make mincemeat of even bones that are considered very safe.
After collecting chips, shards, and sharp fragments of bone from our testing grounds, we canโt help but think that sometimes itโs better not to give your dog that bone.
Also With This Article
Click here to view “Choosing The Right Dog Chew For Your Dog”
Click here to view “Feeding Bones or Raw Foods to Puppies”
-C.C. Holland is a freelance writer from Oakland, California.
