Osteoarthritis

The term arthritis literally means joint (arthr-) inflammation (-itis). It is a general term that describes a variety of diseases that are characterized by inflammation within the joint. This inflammation results in chronic degeneration of joint cartilage and the adjacent bone. Since joint cartilage serves a vital function in the lubrication and cushioning between bones, these disorders uniformly result in progressive joint pain and stiffness. 

Yes, there are many different types of arthritis. For example, septic arthritis is caused by infection, immune-mediated arthritides are caused by joint destruction secondary to another infection in the body (e.g., Lyme disease) and autoimmune arthritis occurs when the body's immune system specifically attacks its own joints. By far, the most common form of arthritis is associated with trauma to the joints. This type of arthritis is more specifically known as osteoarthritis (OA) or degenerative joint disease (DJD).

OA is caused by single or repetitive trauma to a joint. Joints that are unstable, misaligned or contain foreign material are exposed to repetitive trauma. Common joint conditions associated with these types of repetitive trauma include stifles (knees) with ruptured cruciate ligaments or patellar luxations, hip and elbow dysplasia, and cartilage or bone fragments within a joint (e.g., osteochrondritis dissecans or OCD).

OA affects over 8 million dogs in the U.S., which is nearly one in every five dogs. While cats are much more resistant to developing and being affected by OA than dogs, they can also suffer from the disease. 

Dogs commonly develop OA. Some breeds are genetically predisposed to anatomic abnormalities that lead to the progression of OA. For example, dogs that are prone to hip and elbow dysplasia, like Labradors, are predisposed to developing arthritis at those joints.

Older pets of any breed are the most likely to develop arthritis. Studies show that 27 percent of dogs between the ages of eight and 10 and 35 percent of dogs between the ages of 11 and 13 experience OA. 

Additionally, large breed and overweight pets are prone to developing OA. One study showed that 45 percent of dogs weighing 50 pounds or more developed OA at some point in their lives.

A previous trauma affecting a joint or the bones around a joint may also lead to progression of OA. This form of OA is one of the more common forms seen in cats.

Common signs of OA include limping, muscle atrophy, stiffness (especially after sleeping), falling behind on walks, reluctance to climb stairs or jump into a car, repeated licking over a joint, stiffness hours after exercise, personality changes and even loss of appetite. Typically, the symptoms of OA are exacerbated by cold or damp weather and after sleeping or lying on the ground. 

Not necessarily. There are many other disorders that can mimic the signs of OA. Some common examples include other types of arthritis, tumors, fractures, soft tissue trauma, spinal pain (especially Cauda Equina Syndrome, which is often associated with arthritic changes at the spine), neurologic abnormalities and ligament, muscle or tendon injuries. A physical exam and additional testing will likely be needed to differentiate between OA and these other conditions.

During an orthopedic examination, your veterinarian will look to identify common signs of an arthritic joint. These signs include crepitus (a grinding sensation within the joint), decreased range of motion, effusion (swelling within joint), fibrosis (thickened joint capsule), pain, instability, limping and muscle atrophy (wasting). Frequently, a mild sedating pain reliever may be necessary to examine a dog for these abnormalities. 

Many diagnostic tests can be used to diagnose arthritis and to determine the underlying cause of the disease. At a minimum, your veterinarian will need radiographs (X-rays) for diagnosis. It is important to realize that the severity of changes on a radiograph do not necessarily correlate with the degree of lameness or pain your pet is experiencing.    

Medical treatment for OA has greatly improved in the last several years thanks to the introduction and approval of several new drugs and supplements. At this time, there is no cure for this debilitating condition, but there is much you can do to control the pain, make your pet comfortable and perhaps slow down the progression of the disease.

Yes. Many simple changes can be made to help your pet, including maintaining an optimal body weight, providing adequate bedding and warmth (especially while sleeping), massage, physical therapy and improving the convenience of daily activities, such as providing raised food and water bowls or ramps for car travel.

Controlled activity is also important to minimize problems and discomfort. The goal here is to restrict the amount of exercise and joint trauma but still allow enough movement to maintain or increase muscle strength.

Moderate daily exercise is very important. Swimming and leash walking are the safest forms of low-impact exercise. Remember, your pet should not be extremely sore after moderate exercise. If your pet overexerts him/herself, a few days of rest will allow the discomfort to resolve.

The most important aspect of medical treatment is to control the pain associated with OA. Often, we can achieve this with a variety of pain relievers and joint supplements, such as chondroprotectives and omega-3 fatty acids, that effectively limit the pain of arthritis and may also potentially slow the progression of the disease.

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used for chronic pain control in dogs. Opioids, opioid-like medications and corticosteroids also have a role in controlling the discomfort associated with OA.  Corticosteroids are not ideal for chronic use, however, due to the potential for serious side effects.  

NSAIDs are non-steroidal anti-inflammatory pain relievers. Common types used in dogs include carprofen (Rimadyl), grapiprant (Galliprant), meloxicam, and Deramaxx.

As with all medications, there are potential side effects associated with the use of NSAIDs. The most common problems are related to gastrointestinal upset, liver toxicity and kidney toxicity. Fortunately, the side effects are relatively rare and with monitoring, serious problems can often be avoided simply by stopping the medication. 

The newer COX-2-specific inhibitors (e.g., Galliprant, Deramaxx) have even fewer side effects. Signs of these side effects include a decrease in appetite, vomiting, lethargy, diarrhea, increased thirst and urination or blood in the urine. If any of these signs are observed (usually within the first two weeks of starting a new prescription), the medication should be stopped immediately and your veterinarian must be informed. A blood panel will likely be recommended to evaluate for toxicity. 

In an effort to avoid these problems, we suggest having bloodwork and urine analyses performed before and after initiating NSAID therapy. Bloodwork and exams should also be performed every three to six months when an NSAID is used chronically to prevent problems from developing.

Chondroprotectives are part of a general class of supplements called nutraceuticals. These supplements are designed to stimulate the production of cartilage while inhibiting its degeneration. Some may also have the ability to reduce joint pain.

Glucosamine and chondroitin are the most common chondroprotectives, but many others also exist (e.g., MSM, perna mussel). While there is some debate about the effectiveness of oral glucosamine and chondroitin supplements (such as Dasuquin), many pets appear to benefit from these medications. Injectable chondroprotective agents (such as Adequan) may also be used to help pets suffering from arthritis. Clinical studies report decreased pain and increased range of motion with the treatment. 

Dasuquin is a brand of oral dietary supplement that contains glucosamine, chondroitin, and avocado/soybean unsaponifiables (ASU). The glucosamine acts as a building block of cartilage while chondroitin blocks the enzymes that break the connective tissue down. The ASU appears to promote cartilage repair. Dasuquin is an extremely safe supplement with mild gastrointestinal upset as the most common side effect. It is typically started at a high loading dose for four to six weeks and eventually weaned to daily or every other day administration. 

No. While there are many glucosamine and chondroitin supplements on the market, Dasuquin (and its predecessor, Cosequin) are some of the only ones that have been clinically proven to be safe and effective in your pet. Dasuquin is produced under stringent quality standards and is composed of pure molecules that are smaller in size than other formulas. These smaller molecules indicate a higher bioavailability, meaning more medication is absorbed into the body and joints than most other brands. Since dietary supplements are not held to the same quality standards as drugs, many brands will use substandard ingredients and there is often great variation in the amount of the substance that is actually in each individual tablet. In fact, a recent study showed that 80 percent of other brands do not meet label claims for concentrations of glucosamine and/or chondroitin. 

While many pet foods now claim to contain glucosamine and chondroitin, the process of manufacturing commercial foods is likely to degrade these molecules. In addition, the amounts listed on the labels indicate that large volumes of food would need to be ingested to provide the recommended amounts of glucosamine and chondroitin.

A glucosamine and chondroitin supplement should be considered for any pet suffering from arthritis or who is predisposed to developing arthritis. Dasuquin appears to be one of the most effective supplements to slow the progression of OA in your pet.

Adequan is an injectable chondroprotective agent that contains polysulfated glycosaminoglycan. This product has been shown to reduce joint pain, stimulate the production of cartilage and inhibit cartilage destruction, making it one of the few products that not only reduces pain but also has the ability to reverse the changes that are caused by OA. Rarely seen side effects include mild gastrointestinal upset and inflammation or pain at the injection site. 

Typically, treatment with Adequan consists of twice-weekly injections for four weeks followed by monthly injections as maintenance. We usually train owners how to give the injections under the skin at home (similar to giving an insulin injection to a diabetic pet), which reduces the need for frequent visits to the veterinary office. Many pets that required NSAID pain relievers for their daily comfort have been weaned off daily medication after receiving Adequan. 

One of the more exciting recent advances in the treatment of arthritis is based on the study of omega-3 fatty acids. These dietary fats have been shown to provide anti-inflammatory effects for the body and are used in the treatment of a variety of disorders, ranging from arthritis to brain disease. Hill’s Prescription Diet j/d is a specially formulated food that provides a tremendous amount of omega-3 fatty acids and much lower levels of omega-6 fatty acids that are inexpensive to produce but actually have some pro-inflammatory effects in the cells of the body. 

While some dogs will develop mild stomach upset on this diet, pets that are slowly transitioned to the new food over a period of one to two weeks typically do not have any problems. It is important to realize that in order to be effective, the diet should not be mixed with other foods, as that would alter the ratio of omega-3 to omega-6 fatty acids in the diet and the body. This diet has been shown to reduce pain in dogs with arthritis in as little as 21 days. The diet is also designed to help maintain a healthy body weight in arthritic pets.  Similar to the use of Adequan, we have found that many dogs on this diet no longer need consistent NSAID medication to control arthritis pain.

Depending on the underlying cause of OA, surgery or arthroscopy may play a key role in slowing the progression of the disease. This is especially true when surgery can be used to stabilize a joint, correct a misaligned joint or remove foreign material from a joint. Your veterinarian may recommend surgery if it will be helpful in your pet’s underlying disease. Occasionally, surgery will be recommended to remove a source of chronic pain with severe OA that is not responsive to other medical treatments. Examples include joint replacement (currently only available for hips), joint fusion, joint removal and even amputation.

Under guided supervision, alternative therapies such as acupuncture, chiropractics, physical therapy and homeopathy may also play important roles in the treatment of arthritis. Acupuncture appears to be particularly effective in treating certain arthritis-related conditions of the spine.

Since there is no cure for OA, it is unrealistic to expect an arthritic pet to return to a completely normal level of function with no pain and no activity restrictions. Instead, we should expect to see improvement in the signs that can be attributed to arthritis.  By monitoring pain, attitude, activity level and appetite, you can help your veterinarian evaluate the effectiveness of your pet’s treatment regime. It is important to realize that the treatment plan may need to be modified as your pet ages or if signs change. Follow-up visits can be helpful in allowing for effective adjustments to your pet’s individualized arthritis therapy plan.