Dr. Henry De Boer

Question: I am confused about the use of oral nutritional supplements for my dogs joint health. What is your opinion of these products?

Answer:  Working dogs by virtue of their vigorous activity levels tend to tax joints far more than the average pet dog. Accordingly, the wear and tear on joint surfaces (cartilage) can be very significant, and ultimately lead to degenerative joint disease, better known as arthritis.

Arthritis can also develop as a result of a number of genetic and congenital disorders such as hip and elbow dysplasia. Many of our dogs are working with some level of arthritis present, as well as experiencing significant joint changes after being retired from work. The result of these changes can be manifest with pain, stiffness and a loss of normal joint range. Clearly, anything that we can do to minimize these changes will help our dogs to continue to work, play and enjoy retirement comfortably.

In recent years we have witnessed a relatively dramatic increase in the use of oral nutritional supplementation to help manage arthritis.

These oral nutritional supplements have been called chondroprotective agents. Any discussion about how these agents work or how effective they are has to be somewhat vague due to the fact that there is not a great deal of hard scientific information regarding their function or benefit. The majority of information available regarding how these agents may function is theoretical. The information concerning their benefits is predominantly non-scientific testimonials.

Articular cartilage is the surface between joints that provides for smooth low friction movement between bones. Transmission of mechanical forces from one bone to another is also accomplished by articular cartilage.

Arthritis is a disorder of joints that can be characterized by deterioration of the articular cartilage. Additionally we can see abnormal bone formation as well as changes to the soft tissue supportive structures around the joint. In most cases, arthritis in our dogs is caused by trauma within the joint. This trauma is most commonly the result of abnormal stresses within the joint due to joint laxity or instability, or conformational flaws that lead to excessive wear within the joint.

Articular cartilage is not a static tissue. It is constantly remodeling itself to create the healthiest, most efficient and effective joint possible.

Cartilage consists of cells called chondrocytes which synthesize and deposit proteins around themselves to give the cartilage its desired properties. Theoretically, when there are insufficient amounts of the raw materials necessary for this synthesis, the cartilage will deteriorate, and arthritis will develop.

The theory behind the use of chondroprotective agents is to provide increased amounts of those "raw materials" required for cartilage repair and regeneration. Two of the primary raw materials are Glucosamine and Chondroitin sulfate.

The theory behind the use of chondroprotective agents is to provide increased amounts of those "raw materials" required for cartilage repair and regeneration. Two of the primary raw materials are Glucosamine and Chondroitin sulfate.

There are three circumstances in which I typically use chondroprotective agents. If a dog has radiographic evidence of arthritic change in a highly mobile joint, I recommend using the product at the dosage suggested by the manufacturer. It is important to note that in many cases it will be at least six to eight weeks before any meaningful change will be noted in the dogs comfort level and movement. I will also use them subsequent to joint surgery. For example, if a dog tears an anterior cruciate ligament and requires surgical correction it is virtually inevitable that arthritis will ultimately develop in that joint. In this situation I typically recommend approximately one half the manufacturers suggested dosage. The theory behind the use of the product in this fashion is to slow the degradation of the joint that is bound to occur. Thirdly, in dogs that are truly abusive to joints by virtue of their work or activity levels I use approximately one quarter of a therapeutic dose. In my opinion it is impossible to prove any benefit from the administration of these products when they are being used prophylactically. However, given their apparent effect in known arthritic cases as well as their lack of any consequential side effect in the majority of cases, it is difficult to make a case for not using them in such a fashion.

There are a number of these products available and distinguishing between them in terms of benefit is even more difficult than finding scientific evidence documenting their function. Some products are naturally occurring, some are pharmaceutical grade extractions. Most have other agents added as well as Glucosamine and Chondroitin sulfate. I have witnessed apparent positive results with a number of products. As time goes on, more experience is gained, and more research done, we will probably be able to distinguish between these products more confidently as well as seeing improvement in the product themselves. In the meantime we will all have to be comfortable with the anecdotal evidence that supports their benefit to our dogs.

Following his 1973 graduation from Cornell University, Dr. Henry De Boer established Pioneer Valley Veterinary Hospital, based in western Massachusetts, in 1975.

His involvement with working dogs dates to the mid 1960’s when he began training and handling hunting dogs. In 1984 he became involved with the sport of Schutzhund and has gradually risen to the level of national competitor.

Through the years he has worked both in a training and veterinary capacity with a wide variety of working dogs. His knowledge and enthusiasm for working dogs led to the establishment of Working K-9 Veterinary Consultation Services. This service provides veterinary consultations for working canines and is available by phone, fax, or email.

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Working K-9 Veterinary Consultation Service 738 East Mountain Road Guilford VT 05301.