to Arthritis Therapies for Pets
by Shawn Messonnier, DVM
Holistic Veterinarian and Director of Paws & Claws Animal Hospital
There are a number of choices for treating pets with arthritis, as there is truly no one "best" treatment for every pet. I share the holistic belief that each pet is an individual, and must be treated as such. Each owner is different and has different wants and a different budget for the pet. Some owners want to do everything possible for the pet. Cost is not a factor, and we can often experiment and try quite a number of unique treatments. Others opt for a bit less, and may not mind the pet taking medications such as corticosteroids or non-steroidal anti-inflammatory drugs for the long haul. Still others never want any medications, but will only opt for more natural therapies.
My holistic view, desired by most pet owners, involves looking at all options and choosing what works best with the fewest side effects. Drugs such as corticosteroids and non-steroidal anti-inflammatory medications (NSAIDS) are not by nature harmful when used correctly. However, when trying to do the best, most natural and holistic thing for the pet, it would be wise to consider all options before giving up and resigning ourselves to chronic steroid or NSAID therapy for the arthritic pet.
Keep in mind too, that "holistic" doesn't mean "alternative". A truly holistic approach looks at trying to heal the entire pet, and not just cover up symptoms. A truly holistic approach chooses what's best for the pet, trying to give the pet relief while minimizing side effects. Conventional drug therapy can be a part of the holistic approach to the treatment of allergies IF the goal is to help the pet become a healthier pet and not just cover up symptoms while ignoring the pet's well being.
There are some problems with the conventional therapy of arthritis. First, many doctors fail to get a proper diagnosis, and therefore treat their patients incorrectly. While arthritis is certainly the most common diagnosis in older, lame pets, other more serious conditions can also cause lameness. These other causes include but are not limited to bone infections (bacterial or fungal), bone cysts, bone tumors, fractures, ligamentous injuries (cruciate injuries), and joint instability (hip dysplasia, shoulder dysplasia, elbow dysplasia, osteochondritis). I see so many pets that have not received a proper diagnosis, but are being treated for months or years with potentially harmful therapies. Yet often a simple radiograph (X-ray), a test that any doctor is able to perform, will reveal the true cause of the pet's lameness. There is no reason for failing to obtain a proper diagnosis prior to chronic treatment of a pet.
In the end, before we condemn a pet to chronic drug therapy, we should get a proper diagnosis and make sure that our treatment choice is correct.
What is Arthritis?
Arthritis, (also called osteoarthritis or degenerative joint disease (DJD),) is a common condition in older dogs and occasionally occurs in cats. Arthritis means "inflammation of the joint." Inflammation is characterized by swelling, stiffness, and pain. When treating pets with arthritis, our therapy must seek to counteract these effects of inflammation. It is also advantageous if the therapy could slow down the progression of the arthritis or if possible, actually help the joint to heal. While many conventional therapies do a great job of treating inflammation and pain, they usually do not help the joint to heal (in some cases, these anti-inflammatory therapies actually cause more cartilage damage as time progresses.) Conversely, many of our complementary therapies relieve pain and inflammation and actually supply nutrients to help the cartilage heal and slow down the destructive forces of nature which act to destroy the injured joint.
Joints commonly affected with arthritis include the knee, shoulder, ankle, elbow, and most commonly, the hips. The joints between the vertebrae of the backbone also commonly develop arthritis, although this rarely results in clinical signs of pain and inflammation.
The joint includes the bones of the joint, ligaments from surrounding muscles which cross the joint space and attach to the bones, and the joint capsule which encloses the joint. The joint capsule contains a thick protective outer layer and a thin inner layer called the synovial membrane. The synovial membrane contains blood vessels and nerves and makes synovial fluid.
The end of each bone is covered with cartilage called articular cartilage, which acts as a shock absorber to protect the bone. The articular cartilage lacks blood vessels and nerves, and is dependent upon diffusion of nutrients from a special fluid in the joint called synovial fluid. The synovial fluid lines the joint space, nourishing the cartilage and acting as a lubricant and shock absorber.
The lack of nerves in the articular cartilage is an important factor in the progression of arthritis. A great amount of damage may occur to the cartilage before the surrounding joint tissues become inflamed and cause lameness.
The joint cartilage (articular cartilage) has a unique structure which allows it to handle the stressful loads placed on it as the animal walks and plays. The articular cartilage is made of cartilage cells (called chondrocytes in medical terminology) and the surrounding tissue called matrix. The major components of this cartilage matrix are collagen (a type of protein), water, and proteoglycans. The proteoglycan molecule is made of a central core of protein with numerous side chains of glycosaminoglycans (GAGS.) There are several different proteoglycan molecules in the joint cartilage including chondroitin sulfate (the predominant GAG in cartilage) and keratan sulfate. Glucosamine, a popular treatment for osteoarthritis, is a precursor chemical necessary for glycosaminoglycan synthesis.
With years of wear and tear on the joints, the cartilage breaks down and arthritis can develop. As wear and tear continue, the cartilage is disrupted and joint instability results. Chondrocytes, the cells that make up cartilage, are not able to synthesize enough of the proteoglycans to help the cartilage heal. As the chondrocytes become degraded, inflammatory chemicals are released causing inflammation and further damaging the cartilage. The inflammatory chemicals also disrupt the proteoglycans.
With enough degradation of the cartilage, underlying bone might become damaged, and the animal may refuse to use the affected limb. At this point, owners often seek medical care. Some pets can still be helped with nutritional therapies to heal the joint, whereas others may have arthritis that is too advanced to actually allow for healing. The earlier the pet is diagnosed, the greater the chance for healing to occur using complementary therapies.
Conventional and Complementary Therapies for Arthritis
There are many conventional treatments for arthritis including corticosteroids and non- steroidal anti-inflammatory medications (NSAIDS.) Is any one treatment preferred or better for the pet with arthritis? There is no perfect treatment. However, the "most perfect" treatment for arthritis should meet the following criteria:
1. The therapy should be cost-effective.
2. The therapy should be easy for the owner to administer.
3. The therapy must be safe for the pet.
4. The therapy must have minimal or no short and long term side effects.
5. The therapy should help the joint heal itself, as well as relieve inflammation and pain.
No matter what treatment is chosen for the pet with arthritis, it should meet as many of these conditions as possible to be of most benefit to the pet.
There are numerous conventional treatments for pets with degenerative joint disease (arthritis). Unfortunately, some of these treatments have sought to relieve the effects of the arthritis without actually doing anything to help the pet's joints heal.
Remember that arthritis is an inflammatory, painful condition. While the treatment treatment selected must relieve the inflammation and pain, it is important to keep in mind that long term therapy with conventional medications are actually harmful to the joint cartilage. Most of these drugs actually prevent healing of the cartilage, further destroying the cartilage and joint components. So even though the pets will feel better for a while, we're actually making their condition worse. And because many pets taking corticosteroids for prolonged periods of time gain weight as a side effect of this class of medication, this excess weight puts further stress on already damaged joints, adding more insult to injury.
Since most therapies for pets with arthritis seek to relieve inflammation, it's important to understand just what inflammation is and how our therapies help relieve this side effect of arthritis.
Inflammation is caused by damage to the tissues and cells of the affected body part. When a tissue is inflamed it exhibits any or all of the following signs: redness, pain, tenderness, swelling, and loss of function.
Cell membranes contain chemicals called phospholipids. When the cell membrane is injured, as in the arthritic pet, an enzyme acts on the phospholipids to produce fatty acids including arachidonic acid (an omega-6 fatty acid) and eicosapentanoic acid (an omega-3 fatty acid). Further metabolism of the arachidonic acid and eicosapentanoic acid by additional enzymes yields the production of chemicals called eicosanoids. The eicosanoids produced by metabolism of arachidonic acid (the omega-6 fatty acids) are pro-inflammatory and cause inflammation, suppress the immune system, and cause platelets to aggregate and clot; the eicosanoids produced by metabolism of eicosapentanoic acid (the omega-3 fatty acids) are non-inflammatory, not immunosuppressive, and help inhibit platelets from clotting.
Various drugs work at different stages to help decrease the production of the pro- inflammatory compounds. For example, corticosteroids such as prednisone work at 2 places in this biochemical pathway: they help inhibit the enzyme which is responsible for metabolizing the membrane phospholipids into arachidonic and eicosapentanoic acids, and they inhibit the enzyme responsible for breaking down arachidonic acid into pro- inflammatory compounds. Non-steroidal anti-inflammatory medications such as aspirin and ibuprofen work at another step in the pathway called the COX pathway, discussed below, that is responsible for metabolizing arachidonic acid into pro-inflammatory compounds.
Corticosteroids ("steroids",) are commonly used for treating the arthritic dog. Steroids are one of the most frequently used and abused drugs in veterinary and probably human medicine. It's just too easy for doctors to reach for the magic "steroid shot" to treat symptoms without really diagnosing and treating the disease.
Many of my holistic clients think that corticosteroids are horrible drugs that are to be avoided at all costs. However, that is far from the truth. Corticosteroids are actually wonderful drugs that can be life-saving when used correctly at the right dose, for the proper length of time, and in the right patient. So often though, they are often not used at the right dose, for the proper length of time, and in the right patient. Because they can aggravate existing arthritis by inhibiting the synthesis of proteoglycans and collagen, the molecules that make up cartilage, there is rarely if ever a need for their long-term use in the treatment of patients with arthritis.
I believe the best use of corticosteroids is for short term, infrequent use to control pain in pets with mild arthritis. I prefer an initial short-acting injection followed by a 5-7 daily oral dosing. Unless absolutely necessary, depot injections of methylprednisolone which can last in the pet's body for 30-60 days should be avoided.
The negative side effects of long-term use of steroids is that they can decrease the ability of wounds to heal, they increase the chance of infection, they may also actually contribute to further destruction of arthritic joints by decreasing collagen and proteoglycan synthesis, and they can suppress the body's immune system.
Milder short-term side effects seen in most dogs treated with corticosteroids include an increase in appetite, an increase in water intake, and an increase in urine output.
Non-Steroidal Anti-Inflammatory Medications (NSAIDS)
Non-steroidal medications are another group of medications commonly prescribed for arthritic dogs. There are a number of these products, including aspirin, ibuprofen, naproxen, phenylbutazone, piroxicam, carprofen (RimadylR,) Etodolac (EctoGesicR,) and acetominophen (TyelenolR.)
Note: acetominphen is not technically a non-steroidal medication even though it is often and incorrectly prescribed for this purpose; acetominophen has no anti-inflammatory properties.
Since dogs have shown greater toxicity (usually increased GI side effects) with most of the human NSAID medications, it is questionable if they should be used in dogs for any reason. As a result of this increased sensitivity towards NSAID side effects, the pharmaceutical companies are developing products which are safer for our canine patients.
Like corticosteroids, the NSAIDS work by inhibiting the chemicals (prostaglandins) that cause pain and inflammation. While they can be very useful in controlling pain and inflammation, like corticosteroids they too have side effects, some more serious and dangerous than others (see below.)
Non-steroidal medications work in something called the COX pathway. COX stands for cyclooxygenase, which is another enzyme in the pathway that break down the arachidonic acid in the cell membranes of the joint into chemicals such as free radicals and various prostaglandins that damage the articular cartilage.
There are 2 COX enzymes that have been discovered to date: COX-1 and COX-2. COX- 1 is found in various tissues such as the stomach, intestines, and kidneys and serves an important role in maintaining health. When arachidonic acid is broken down by COX-1, good, anti-inflammatory prostaglandins are produced. These prostaglandins keep the kidneys functioning normally and help protect the stomach and intestinal tract against ulcers.
When arachidonic acid is broken down by COX-2, bad, pro-inflammatory prostaglandins are produced. These prostaglandins (and other chemicals) are harmful and contribute to the side effects seen in some patients taking NSAID medications, such as GI ulcers and kidney disease. Drugs that selectively inhibit COX-2 but not COX-1 are most likely to result in fewer side effects and be safer for our patients. Right now the move is on in human medicine to find NSAIDS that inhibit COX-2 but not COX-1; hopefully our veterinary patients will benefit from this research as well.
Current NSAID medications available for veterinary patients inhibit both COX-1 and COX-2 to various degrees. Indomethacin and piroxicam have high COX-2/COX-1 ratios, and result in high incidences of GI problems (bleeding, ulcers). Naproxen, ibuprofen, carprofen (RimadylR) and etodolac (EctoGesicR) have lower COX-2/COX-1 ratios, and as a result have fewer incidences of GI problems. Aspirin has a higher ratio but an intermediate incidence of GI problems, indicating that other mechanisms are involved in causing some of the side effects we may see in patients taking NSAIDS.
As mentioned, the NSAIDS have the potential to produce a number of undesirable and potentially fatal side effects. One side effect is gastrointestinal bleeding that occurs because of prostaglandin inhibition. Other side effects include kidney disease (also due to prostaglandin inhibition,) liver disease (mild cases display elevated liver enzymes whereas more serious cases can show liver failure,) immune diseases (anemia, low platelet count, skin diseases,) neurologic signs (seizures, paralysis, unsteadiness,) behavioral problems (hyperactivity, aggression, depression, or sedation,) drug interactions (NSAIDS should not usually be used when corticosteroids are used as the potential for side effects increases,) and even death. Finally, and perhaps most importantly, as with steroids, many of the non-steroidal medications destroy cartilage, although the popular NSAIDS RimadylR and EctoGesicR appear to cause less cartilage destruction than other NSAIDS.
Can NSAIDS be safely used in the treatment of arthritis? I believe NSAIDS can be safely and effectively used short-term (5-7 days) in pets not taking any other medications and in pets without other diseases. This means a careful history, examination, and laboratory testing will be needed in most pets. For long-term use (which is rarely necessary as most pets do very well on complementary therapies as discussed in Part III,) I only use NSAIDS if ALL OTHER TREATMENTS HAVE FAILED, AND IF THE OWNER HAS BEEN WARNED OF POTENTIAL SIDE EFFECTS. These patients are frequently (every 2-3 months) monitored for side effects, and GI protective medications (see below) may be used to decrease GI side effects. In effect, we try to make the patient comfortable and have a good quality of life at the risk of causing side effects and even death in that pet.
As I mention in The Arthritis Solution for Dogs (Prima Publishing) "Blanket therapy with anti-inflammatory drugs is a poor substitute for a well-designed program of management."
Complementary Therapies for Pets with Arthritis
While conventional therapies can be useful for short-term pain relief in pets with arthritis, most dogs and cats will improve significantly when treated with complementary therapies. This final article will provide a brief overview of the most popular complementary therapies available for treating arthritis.
Homeopathy uses diluted substances to help the body heal itself. Individual remedies are selected based upon a careful history and physical examination of the arthritic pet. Several remedies can be combined in solutions such as those made by HomeoPet that are available for short-term use of mild lameness. Common individual remedies include: Caulophyllum, Lithium Carb., Rhus Tox., Bryonia, Hecla Lava, and Actaea Rac.
Traditional acupuncture involves the placement of tiny needles into various parts of a pet's body. These needles stimulate acupuncture points which can effect a resolution of the clinical signs. Other forms of acupuncture involve laser therapy, aquapuncture (tiny amounts of vitamins are injected at the acupuncture site for a more prolonged effect,) and electroacupuncture (a small amount of non-painful electricity stimulates the acupuncture site for a more intense effect.)
As a rule, results from acupuncture compares quite favorably with traditional therapies. Side effects from acupuncture are rare. Accidental puncture of a vital organ can occur. Infection can occur at the site of needle insertion. Occasionally, the needle can break and surgery may be needed to remove it. Some pets require sedation in order to allow insertion of the acupuncture needles. In some animals, signs may worsen for a few days before they improve.
Many owners worry that acupuncture is painful and that their pets will suffer. Usually acupuncture is not painful. Occasionally, the animal will experience some sensation as the needle passes through the skin. Once in place, most animals will relax and some may become sleepy. Fractious animals may require mild sedation for treatment.
The number of acupuncture treatments that a pet will require varies from pet to pet. Usually, we try at least 8 treatments (2-3/wk) to assess if acupuncture will work. On average, treatments last about 15-30 minutes for needle acupuncture, and 5-10 minutes for aquapuncture or electroacupuncture. If the pet improves, acupuncture is done "as needed" to control the pet's signs.
In recent years, therapy using magnets has gained a following among some doctors and pet owners. It is seen as a safe a simple method of treating various disorders, often producing positive results without side effects or much expense.
Doctors theorize that magnets work by means of magnetic lines of force; units called gauss measure the strength of the magnetic field. The higher the gauss number the stronger the magnet (a 1000 gauss magnet is stronger than a 100 gauss magnet.) Magnets are used either as permanent magnets, also called static magnets, or as pulsed electromagnetic field magnets (PEMF). Static magnets come in bars, beads, or strips. PEMF uses pulsing current flow through a wire coil to create a magnetic field around the wire: the greater the amount of current flow, and the greater the number of turns of the wire, the greater the magnetic field that forms. In people PEMF is approved for treating nonunion fractures (fractures that have failed to heal) by the FDA. Other uses include avascular necrosis of the hip, osteoarthritis, and rotator cuff injuries. No toxic effects have been reported using magnetic therapy.
In our Western view of healing, magnets appear to heal the body by removing inflammation and restoring circulation. By increasing blood flow to a diseased site, increased nutrients are available for healing. In the Eastern view of healing, magnets help restore the energy flow of the body to allow healing and proper metabolism. This is similar to one of the theories used to explain the positive effects of acupuncture as well.
While usually safe, magnets should not be used in acute infectious conditions, on cancerous growths (although some doctors do find them useful in treating cancerous tumors), in acute injuries, pregnant animals, or in dogs with cardiac pacemakers.
There is a normal amount of wear and tear on the joint cartilage. The various cells and fluids are constantly being broken down and synthesized. It is important that the cartilage receive proper nutrition, especially when it is damaged and inflamed. Chondroprotective agents seek to replenish the raw materials that are essential for the healing and synthesis of cartilage, its matrix, and joint fluid. There are various products, each supplying different nutritients, that are available to assist in relieving inflammation and helping cartilage to heal when it is damaged. The following ingredients are among those most commonly included in chondroprotective nutritional supplements.
In the laboratory, shark cartilage has been shown to contain chemicals that inhibit blood vessel formation. Because arthritis is an inflammatory condition, and inflammation requires blood vessels, it has been suggested that by inhibiting the formation of new blood vessels shark cartilage can benefit arthritic pets. In studies in people and in dogs, significant improvement is seen in patients suffering from arthritis. In one study, 80% of dogs showed improvement when treated at a dosage of 750 mg/5 kg of body weight for 3 weeks. The relief from pain and inflammation was theorized to occur as a result of decreased blood vessel formation; improvement may also result from a relief from pain due to the large amount of mucopolysaccharides (GAGS) contained in the shark cartilage, which can help nourish and heal the joint cartilage. The main problem with using shark cartilage to treat arthritis is the large dosage required which is expensive and requires giving a large number of capsules to the pet each day. Environmentalists are concerned about the harvesting of sharks to produce the supplements. Since other supplements work as well if not better than shark cartilage, and are more affordable, most doctors do not use shark cartilage for treating dogs and cats with arthritis.
In dogs treated with bovine cartilage, good results were seen in the treatment of degenerative disk disease and some spinal disorders. Like shark cartilage, bovine cartilage is high in glycosaminoglycans which can help the body repair damaged joints. The recommended dose of bovine cartilage is 200 mg/25 pounds of body weight.
Perna Canaliculus, the green-lipped mussel, is a shellfish that is a natural source of highly concentrated glycosaminoglycans (GAGS) including chondroitin, as well as a number of other nutrients, including complex proteins, amino acids, nucleic acids, naturally chelated minerals, and an inhibitor of prostaglandin synthesis which makes it effective as an anti-inflammatory supplement. Perna is inexpensive and readily accepted by most dogs; the recommended dosage is 300 mg/15 pounds of body weight.
The sea cucumber (Cucumaria frondosa,) also known by the names "trepang" and "beche de mer" are marine animals related to urchins. It is believed that these organisms inhibit harmful prostaglandins involved in causing pain and arthritis. They are also rich in nutrients needed by cartilage including chondroitin and mucopolysaccharides, and several vitamins and minerals. One popular product supplies the sea cucumber in a unique "jerky-type" treat which dogs find quite palatable. Other compounds found in this product include sea kelp, natural vitamin E, lecithin, garlic, omega-3 fatty acids, and glucosamine hydrochloride. Each jerky treat provides 1200 mg of chondroitin. These treats are perfect for the dog or cat who is hard to medicate. The jerky treats can also be used in conjunction with other similar pill supplements, as it is unlikely to overdose a pet on glucosamine or chondroitin. Many owners will give their dogs their recommended amounts of daily pills but will also reward the dog with a jerky treat. For those pets with arthritis I like the idea of giving them a daily treat that is good for them as is the case with this jerky product.
Glucosamine is the most commonly used chondroprotective supplement used for the treatment of osteoarthritis (chondroitin is the second most commonly used supplement for the treatment of osteoarthritis.) Glucosamine is an aminosugar that is incorporated into articular (joint) cartilage; it is supplied as a supplement in one of three forms: glucosamine sulfate, glucosamine hydrochloride, or N-acetylglucosamine. Studies show that while all 3 forms of glucosamine are effective, glucosamine hydrochloride and glucosamine sulfate were more effective than N-acetylglucosamine. Glucosamine is rapidly taken up by cartilage cells and helps stimulate the synthesis of synovial fluid and cartilage and also helps inhibit the destructive enzymes that can destroy cartilage and proteoglycans. The anti-inflammatory aspect of glucosamine may result from the scavenging of harmful free radicals (similar to antioxidants.) Glucosamine is used by the cartilage for the synthesis of glycosaminoglycans. A number of studies in people and pets show that glucosamine is equally effective for treating osteoarthritis when compared to NSAIDS without the side effects.
Glucosamine is very safe supplement with no side effects; mild GI upset is rarely observed. Dosages vary depending upon the product. As a guideline, a starting dose of 1000-1500 mg of glucosamine is recommended per day for a 50-100 pound dog. This dose is then lowered after 4-8 weeks.
Chondroitin sulfate is the major glycosaminoglycan found in cartilage; it also helps inhibit enzymes that are destructive to the joint and has been shown to be is an effective treatment for osteoarthritis. Since chondroitin production by the body decreases with aging, supplementation with this compound may be especially helpful for older pets with arthritis.
Chondroitin is often added to supplements containing glucosamine; 800-1200 mg of chondroitin is recommended per day for a 50-100 pound dog. While significant studies are lacking, many feel that adding chondroitin to glucosamine enhances the ability of both substances to repair cartilage.
The following points concerning chondroprotective therapy are important to maximize success when using these supplements:
1. They are equally effective when compared to NSAIDS but much safer for the pet.
2. Cost may be an issue for some pet owners. The typical daily cost of using a glucosamine-chondroitin supplement is approximately $1.50/day for a 50 pound dog. This cost can decrease as the dosage of the supplement is lowered to allow the owner to use the least amount of supplement to maintain pain relief. However, the comparable cost of the most popular NSAIDS is approximately $2-3/day for a 50 pound dog, making nutritional supplements less expensive.
3. Since these supplements nourish living cartilage cells, they are most effective when used early in the course of the disease. This requires adequate and early diagnosis.
4. Because they are not drugs but rather nutritional supplements, response may not be seen for 4-8 weeks (response to drugs is typically immediate.) During the first 4-8 weeks, an increased "induction" dose is used and then the dose is lowered as improvement is seen. Additional short term therapy (with NSAIDS, acupuncture, etc.) can be used during the induction phase.
5. The supplements can also be used effectively when no clinical signs are present but yet disease exists. In my practice, many dogs are diagnosed via screening radiographs with hip dysplasia and started on the supplements.
6. Purity of the products is important. There are many generic "knock-off" products that sell for much less than patented products. Studies that have been done showing the effectiveness of these compounds have used pure grades of products. Products of lesser purity, while often costing less, may also be less effective. Unlike traditional drugs these compounds are not regulated and labelling can be inaccurate or misleading; manufacturers are not required to analyze their products regarding purity, uniformity, or content. Purchase only quality products from reputable manufacturers as recommended by your doctor.
7.Because the chondroprotective supplements are so effective after 4-8 weeks in improving signs seen in arthritic pets, the diagnosis should be reevaluated after this period of time if improvement is not seen.
Dr. Shawn Messonnier is author of the Natural Vet series from Prima publishing, which includes The Arthritis Solution for Dogs, The Allergy Solution for Dogs, and the award-winning The Natural Health Bible for Dogs & Cats. For your weekly dose of holistic pet care, read Dr. Shawn's column The Holistic Pet,/b> in your local paper. He can be reached at 972-867-8000, firstname.lastname@example.org, or at http://www.petcarenaturally.com.