New medicines and treatments are improving the outlook for dogs with arthritis
Leslie Crane Rugg is a freelance writer whose inspiration comes from her four Collies. She has edited several breed-oriented magazines and newsletters, and has had five novels published.
The mechanics of arthritis are no mystery. Ongoing wear and tear causes cartilage to deteriorate, and lubricating fluid to dry up, leaving hones to rub (in mild cases) or grind (in severe cases). Even different causes and forms of arthritis result in similar symptoms. Except for the few cases that respond to reparative surgery, the disease is incurable. Until most recently, palliative treatments were the best veterinary medicine could offer. Anti-inflammatories, analgesics, and steroids reduce pain but do nothing to prevent further degeneration. Today, cutting-edge Western medicine, complementary medicine, and traditional Chinese medicine provide a more effective arsenal of drugs, nutraceuticals, practices, and remedies that are capable of improving, or possibly stimulating some regeneration of, the affected joints and vertebrae.
It Starts at the Mouth
Osteoarthritis, the most common of arthritic diseases, is a process. The aches and pains, lameness, and stiffness we associate with the disease can manifest in one or all the telltale spots. But the process can start in the mouth, via neglected dietary needs and dental care.
Large- and giant-breed puppies are particularly susceptible to periods of rapid weight gain. Commercial puppy food formulas, although balanced according to government regulations, may provide too many calories rather than the correct nutritional density necessary for gradual, consistent growth. The added calories may provide energy but they also add poundage that puts undue stress on young hones, joints, and tendons, especially for those dogs who have a genetic predisposition to hip dysplasia.
Bernadette Cruz, DVM, whose special interest is in senior dogs and their health problems, prescribes lifelong adherence to good-quality adult food for these breeds. She agrees with breeders who suggest switching from a puppy formula to an adult formula at 4 to 6 months of age rather than at the customary 1 -year point. Puppies will still grow, but at a more constant rate. Owners of these puppies must control the ratio of fat and protein as well as the ratio of protein to calorie. Obesity, adds Cruz, "is one of the main problems hastening arthritis."
The health of teeth and gums also plays a significant role in preventing the onset of arthritis. Cruz points out, "Whcn the gums are compromised, bacteria in the mouth can travel to the liver, kidney heart muscle, and joints." By incorporating good habits of nutrition and dental care from puppyhood, dogs get the head start they need to avoid or mitigate the effects of degenerative joint disease.
An Equal-Opportunity Disease
Arthritic pain is more commonly-but not exclusively-seen in older dogs. Puppies may wave proverbial red flags if they display a 'bunny hop" gait, using both rear legs together once in full motion. Cruz notes that dogs who stand in cowhocked or bowlegged positions can be exhibiting signs of potential structural problems.
Further evidence of an early arthritic condition, Cruz says, is seen when "a normally high-energy pup is suddenly too calm or moving too slowly. It may indicate that animal is in pain." She recommends early detection to diagnose the problem before it endangers a young dog's quality of life.
A study conducted in 2001 at the University of Pennsylvania examined almost 16,000 PennHip reports and identified hip joint laxity as the first real predictor of canine arthritis. The amount of surplus play between the femur ball and the hip socket parallels increasing odds for arthritic development. The study also found that as much as 70 to 80 percent of members of certain breeds are prone to arthritis. Size does not affect whether a dog is prone to arthritis, though it does influence where the condition occurs. Arthritis in smaller breeds seems to center on the knees. Elongated breeds may show weaknesses along the spine. Larger breeds are more likely to develop hip joint problems.
From the study's database, Golden Retrievers, Labrador Retrievers, German Shepherd Dogs, Newfoundiands, and Saint Bernards were cited as breeds most susceptible to degenerative joint disease. Bullmastiffs and Bernese Mountain Dogs are also at risk. A majority of X-rayed 2 year-old Golden Retrievers already showed signs of osteoarthritis; 90 percent of senior Goldens tested were symptomatic. Statistics also confirmed that Borzoi and Greyhounds, breeds developed for their speed or athleticism, rarely develop this condition.
0ther breeds have a genetic propensity for developing other forms of arthritis. Airedale Terriers, Bearded Collies, Bichons Frises, Cairn Terriers, Greyhounds, and Shetland Sheepdogs are prone to rheumatoid arthritis. This immune-mediated disease is brought on by the body's inability to distinguish between its own and foreign proteins. The antibodies produced, known as the rheumatoid factor, combine with protein to form immune complexes that lodge in the joint and cause inflammation. Once the cycle has begun, the body's defenses produce more erosion of the joint and neighboring bones.
Dogs afflicted with this type of arthritis may also experience organ or systemic involvement, such as enlarged lymph nodes, kidney disease, pneumonia, and tonsillitis. According to Dr. George Padgett's data on canine genetic diseases, immune-mediated polygenic-arthritis most often affect, Akitas, American Cocker Spaniels, Beagles, Collies, Doberman Pinschers, German Shepherd Dogs, Golden Retrievers, Irish Setters, Labrador Retrievers, Nova Scotia Duck Tolling Retrievers, Poodles, Shetland Sheepdogs, and Tibetan Terriers.
Another well-known and serious immune disease, systemic lupus erythematosus, is actually a form of arthritis that inflames muscles and tendons, rather than cartilage and bone. American Cocker Spaniels, Australian Shepherds, Beagles, Bearded Collies, Bedlington Terriers, Belgian Sheepdogs, Bernese Mountain Dogs, Bichons Frises, Boxers, Collies, Dachshunds, English Pointers, Fox Terriers, German Shepherd Dogs, Old English Sheepdugs, Poodles, Scottish Terriers, Shetland Sheepdogs, Siberian Huskies, and Toy Fox Terriers are the breeds that Padgett identifies as predisposed for this disease.
Help is on the Horizon
A relatively recent addition to the nonsteroidal antiinflammatory class of drugs (NSAID5) are cox-2 inhibitors. "Cox" refers to the cyclo-oxygenase cnyme that converts fatty acids into a hormone-like substance that produces inflammation. There are two main forms of cox, cox- 1 and cox2. Cox- I is usually found in the stomach, intestines, and other places swelling occurs, and it makes sure that the natural mnucosa protects the inflamed site as well as the lining of the gastrointestinal tract (GI). Cox-2 is similar, but is not found in the stomach or intestines, only in other parts of the body Drugs such as aspirin not only reduce inflammation, but also end up blocking cox- 1 from protecting the GI, which can lead to the tract ulcerating and bleeding. Thus, antiinflammatory medications that preserve cox- I and inhibit cox 2 function more safely, saving the stomach and intestines.
Although drugs such as Vioxx for the human market have been withdrawn due to a potential risk of heart attack and stroke, similar drugs for veterinary use, such as deracoxib and carprofen, do not affect dogs in the same way. Dr. Steven Fox, Novartis Animal Health director of Pain Management and president of the Veterinary Orthopedic Society, cites a Cornell study investigating atherosclerosis (hardening or constricting arteries). Out of 12,600 necropsies, only 21 cases were found, and each of these dogs had an underlying adrenal or thyroid problem. Fox notes that "dogs have collateral compensation; they have the capacity to create new arteries around the heart." High blood pressure, he says, "is another human risk factor rarely found in dogs."
The reality of cox-2 inhibitors is that, despite their powerful abilities to reduce swelling and relieve pain, side effects such as vomiting, diarrhea, and loss of appetite still exist. Both Novartis and Pfizer, which manufacture Deramaxx (deracoxib) and Rimadyl (carprofen), respectively, warn that dogs with pre-existing digestive, kidney, or liver conditions are questionable candidates for taking these drugs.
Breeds with bleeding disorders and dogs with low or abnormal platelets also should not be prescribed NSAJDs because of their anti-clotting tendency Derainaxx is not encouraged for Dobermans or white-coated breeds because it is a sulfonamide, or sulfa-based drug, which can increase the potential for liver necrosis in breeds like these that are sensitive to sulfa and sulfonamides. Rimadyl also may cause liver dysfunction. Consequently, dogs given cox-2 inhibitors need regular blood chemistry profiles. Fox also cautions against mixing drugs. He specifically warns., Do not give aspirin to a dog on NSAIDs because the combination will produce a very dangerous interaction."
Many people have begun to look for more natural alternatives in seeking pain relief for their dogs. Glucosarnine, chondroitin, and methylsulfonylmetha.ne (MSM) are all substances that the body produces and needs in order to protect itself from inflammation and breakdown.
An effective pain reliever, glucosamine is a powerful amino acid/sugar compound that can help the body regenerate cartilage. Glucosamine is also a formative component of chondroitin, which is also essential to cartilage structure, as well as metabolism.
Studies show that chondroitin also diminishes pain while aiding in healing and regrowth.
Like glucosamine, sulfur-based MSM is another amino acid compound that helps the body produce cushioning collagen for connective tissue, revitalize and detoxify cells, and decrease inflammation.
Vitamin C is another useful substance for the immune system, and though humans need to get it from their diet, dogs can create it. But a stressed or injured body requires more vitamin C than can be naturally produced. Ester-C or sodium ascorbate are two easily digestible forms of the vitamin that act to protect chondrocytes that manufacture new cartilage, reduce inflammation, and boost immune system response. Vitamin C is also an antioxidant that acts as a scavenger, devouring free-radical, reactive molecules that damage cartilage and other tissues.
Antioxidants have been proven to function as antiinflammatories and can therefore aid in pain relief A 1990 Norwegian study led by veterinarian Gier Berge, testing the value of Ester-C in 100 dogs with joint and connective tissue disease or injury, showed a 75 percent improvement in one week.
Omega 3 and Omega 6 fatty acids have also been recognized as effective anti-inflammatories. Because diet for an arthritic dog is so significant and because statistics indicate that 50 percent of all dogs are close to or in their senior years, commercial dog food companies have begun to create formulas for this population. Fifteen years ago, Purina entered the therapeutic diet market for certain nutritionally manageable health conditions. The newest product is Purina Veterinary Diets JIvI Joint Mobility. Purina Veterinary Nutritionist Dottie Laflamme explains, "In animals suffering from arthritis, there are metabolic changes that respond in a positive way to increased levels of these fatty acids. In addition, PVD JM contains a natural source of glucosamine, and increased amounts of anti-oxidants."
Holistic veterinarian Nancy Scanlan contends that a good diet and certain supplements help prevent the development of arthritis." At the top of her list is a natural raw food diet that contains nothing artificial and no animal by-products. For her arthritic patients, she prescribes a neutral pH form of vitamin C; vitamin F; amino-acid- and endorphin-stimulant di-phenylalanine (DLPA), that controls chronic bone and muscle pain; a glucosamine sulfate product; antioxidant enzyme superoxide dismutase; Chinese herbal Mobility 2; and Adequan (an injectable chondro-protective nutraceutical). Scanlan also performs acupuncture and suggests chiropractic, especially for performance and high-energy dogs.
With any individual or rnultiinodal course of treatment, the goal, as Fox states, is 'to minimize organic dysfunction while diminishing pain and providing quality of life." Before treatment, proper diagnosis must take place. As with so many things in life, timing is key.
Cruz exhorts dog owners to pay attention to subtle signs. She says, 'You know your animals better than anyone else. Don't wait for your vet to ask questions; bring them up yourself" Having arthritis and suffering painful decrepitude are no longer requisite partners, thanks to the wide range of medical approaches available today.