Visiting Veterinarian

Better than a tooth brush?

By Michele Gerhard Jasny V.M.D. - January 19, 2006

While sitting in the dentist's chair recently, I was asked when I was going to write about The Greenies (Trademark symbol after Greenies throughout story) Controversy. "Wud..eenie... on-roo-er-ee?" I mumbled. My dentist and her staff are all animal lovers, so our conversations frequently turn to pets. "What Greenies Controversy?" I repeated, once I could rinse and spit. Greenies is an over-the-counter doggie product, marketed as a "multifunctional dental treat." A hard, tasty chew shaped like a big, lumpy toothbrush and colored a rich green, when Chomper gnaws on it, it mechanically scrapes debris from the surface of his teeth. According to the Greenies web site, independent studies have shown that feeding Chomper one a day results in 62 percent less tartar build-up, 14 percent decrease in plaque formation, 33 percent less gingivitis, 77 percent less dental staining, and 31 percent less bad breath. So what could be bad?

"It's all over the Internet," my dentist said, aiming an ominous looking instrument at me. "They're saying Greenies are dangerous, that a bunch of dogs have died from them. Someone even said they have an addictive ingredient in them." As a 21st-century veterinarian, I'm used to spending a lot of time researching (and debunking) Internet rumors, but I have learned that nothing is too bizarre to be true. "I'll check it out," I said, ending the discussion as wads of cotton being stuck in my mouth rendered further conversation impossible.

Later, back at home and too numb to eat lunch, I began my research. It seems that back in the late 1990s a couple named Dr. and Mrs. Roetheli had a Samoyed named Ivan with chronically stinky breath. The Roethelis teamed up with a "well-known board-certified veterinary nutritionist" and developed a formula for the Greenies treat. The ingredients are concentrated wheat gluten, glycerin, powdered cellulose fiber, natural flavor, monosodium phosphate, fatty acids, magnesium stearate, and chlorophyll. None of these are unusual, toxic, or addictive. The "natural flavor" is undisclosed, being listed as "proprietary" but the web site states that it "contains no beef protein." This information is probably to cater to vegetarians, as the web site emphasizes that the ingredients are of "non-animal origin." The treats come in sizes ranging from Teenie to Jumbo, and have reputedly become the most popular canine dental chew in America. The feeding guidelines say that Greenies should not be used in dogs less than six months old, less than five pounds in weight, or who tend to gulp their food, and that owners should be sure to use the correct size for their dog. Then they add " Caution: As with any edible product, monitor your dog to ensure the treat is adequately chewed. Gulping any item can be harmful or even fatal to a dog."

Problems can occur
Exactly. Here's the controversy. There have been reported cases of Greenies causing esophageal or gastrointestinal obstructions in dogs. Some officially documented, others not. Some of the cases have been fatal. But before jumping to conclusions, let's consider a few things. Almost anything that Chomper swallows in a chunk has the potential to cause an obstruction. A bone. A piece of steak. A rawhide. A toy. That's why our mothers told us to chew our food. Chunks of stuff can get stuck in a variety of locations. Many of the Greenies cases involved the esophagus, the tube that goes from the mouth to the stomach via the chest. Removing an esophageal foreign body is tricky. It can sometimes be done with a fiberoptic endoscope. Other times it requires more invasive surgery. In either case, the trauma to the esophagus can lead to serious complications such as life-threatening infections or scarring that permanently affects function. Greenies chunks have also gotten stuck in dogs' stomachs and intestines. Because Greenies are especially designed to be hard, crunchy, and crumbly, anecdotal discussions by veterinarians suggest that they are particularly challenging to grasp and remove when surgically or endoscopically trying to relieve an obstruction. The risk of things getting stuck increases as the size of the dog decreases, the majority of problems occurring in small dogs, especially those less than ten pounds. So as long as Chomper is a big dog, you don't have to worry. Right? Not exactly. Large dogs have also had problems. Although advertised as "100 percent edible" and "85 percent digestible," that is assuming Chomper chews them up. They are not intended to be swallowed in large pieces. Big chunks may pass, but if they get lodged somewhere, we can't depend on their "digestibility" to solve the problem. Anything Chomper likes to chew creates some risk, including rawhides, bones, and other compressed vegetable chews and dental treats. The denser the material, the greater the risk.

Facts and hearsay
As I read the barrage of Pro-Greenies and Anti-Greenies, there were some fascinating, if unsubstantiated, comments. There were several reports of dogs fracturing teeth on Greenies, but one dental specialist said he had seen more dogs break teeth on ice cubes. Several people advised lightly nuking Greenies in the microwave to soften them before feeding. One person said that you could use a Greenies to hammer a nail into a board. I haven't tried this but plan to as soon as I have that kind of time on my hands. This is all hearsay. Don't quote me. Don't sue me. If you try the hammer-nail-board thing, call me and let me know if it's true. As far as an "addictive substance?" My search engine spit out a bunch of articles about the use of amphetamines in pro baseball. The addictive pills are apparently called "greenies" in the locker room. I suspect this is where the "addictive ingredient" rumor began.

On the positive side, Greenies have the Seal of Acceptance of the Veterinary Oral Health Council for both tarter and plaque removal. For dogs that chew them adequately, Greenies undoubtedly promote dental health and lessen the frequency with which Chomper may need professional dental cleanings requiring general anesthetic. There were numerous comments of satisfied customers who have never had a problem and who love the product. I wish we could collect statistics comparing the number of dogs that have died due to problems related to severe dental disease, the number of dogs who have died due to anesthetic complications during dental procedures, and the number of dogs who have died from Greenies obstructions. I have little doubt we would find that, statistically, Greenies do more good than harm. That won't ease the grief of the people who have lost pets due to Greenies obstructions. If Chomper is teeny, or doesn't chew his treats carefully, I might choose a different product. The company actually makes a product called Li'lbits (trademark) that is for tiny dogs or those that gulp their food. But if Chomper's been eating Greenies happily for years, you have to make your own decision. I'm not sure that they are any riskier Accidents happen. Dogs swallow stuff. The best we can do is make the best choices we can at each moment.