How ARTHRIX for Dogs and Cats Works

What Causes Arthritis
Canine Hip Dysplasia
Feline Hip Dysplasia
Pet Arthritis

What Causes Arthritis?

Prostaglandins and Leukotrienes

The following information gives some background information on what causes arthritis at the cellular level. Prostaglandins are a group of hormone-like substances present in many tissues and body fluids. They act as regulatory substances and messengers. Prostaglandins are not hormones as they are not produced by glands. They are metabolized on site and used very quickly. Their effects are strictly local, and modulate the tissues in which they are formed. Prostaglandins are vital regulators - they control every cell and organ in the body. Their functions include the regulation of platelet aggregation, the lowering of blood pressure, the regulation of body temperature, the function of nerve transmission, the action of certain hormones and the control of inflammation and vascular permeability. So, it is easy to see how something that regulates these prostaglandins would be of great benefit to our pets.

Most prostaglandins are biosynthesized during the metabolism of arachidonic acid (arachidonic acid, AA, is an essential fatty acid). Other prostaglandins are formed during the breakdown of omega 3 and omega 6 fatty acids (see Figure below). Not all prostaglandins are beneficial. PG1 prostaglandins and EIC3 prostaglandins are important examples of good prostaglandins; while prostaglandins formed by the cyclooxygenase pathway (COX 2) of arachidonic acid metabolism (PG2) have potent inflammation-supporting properties. Bad prostaglandins are capable of attracting large numbers of leukocytes (white blood cells) to the site of inflammation, causing pain and tissue damage.

Beneficial prostaglandins (PG1 and EIC3) play an important role in reducing inflammation by improving cell permeability and blood flow, thereby reducing pain, tenderness and stiffness. Long-term daily intake of Essential Fatty Acids (such as contained in the supplement ARTHRIX for Dogs and Cats), will regulate the arachidonic acid metabolism, supporting the formation of good prostaglandins and inhibiting the formation of bad prostaglandins.

Leukotrienes are products of the lipooxygenase pathway of arachidonic acid metabolism and play an important role in the inflammatory process. Like prostaglandins, they are short-lived, locally-active hormone like substances. Leukotriene LT4 and its metabolites LTC4, LTD4 and LTE4 have important inflammation-supporting properties. Leukotriene LT4 and its metabolites are potent chemotactic agents. What this means, is that they falsely attract white blood cells whose normal function is to destroy unwanted bacteria, protozoa, cells and cellular debris, to the site of injury. Once there, these otherwise useful cells start to attack healthy tissues. This inability to differentiate beneficial cell tissue from unwanted foreign substances is know as a auto-immune disorder, and lead to arthritis and a host of other inflammatory diseases.

Canine Hip Dysplasia¹

CLICK HERE for a Chart of Common Canine Joint Diseases

It is important to distinguish between Canine Hip Dysplasia (CHD) and Degenerative Joint Disease (DJD). Hip Dysplasia is the abnormal development of the hips which results in an increased amount of looseness in the hip joint. Degenerative Joint Disease (arthritis) is the changes within the joint which occur as a result of this increased looseness. Pain can result from either of these problems. Young dogs with hip dysplasia can be in pain without having degenerative joint disease, and dogs with chronic DJD do not always have hip dysplasia.

Young Dogs With Hip Dysplasia

Pain relief associated with conservative treatment are derived from strengthening the joint capsule and preventing further capsuler sprain. Initially, painful dogs should be treated for acute sprain. Complete rest is mandatory for two weeks. Physical therapy during this time can be performed to maintain good range of motion. However, resuming normal activity early can predispose to further injury, pain, and prolonged recovery. According to one source, approximately 60% of young dogs treated conservatively return to acceptable clinical function with maturity.

Mature Animals With Chronic DJD

Medical therapies for chronic degenerative joint disease can be subdivided into 3 areas - weight control, proper exercise, and anti-inflammatory substances.

Weight Control: Regardless of whether or not a dog has hip dysplasia, they will be at higher risk for joint disease if they are over weight. The further they are from their ideal weight, the more likely they will be to have orthopedic problems such as arthritis, intervertebral disk disease and cruciate ligament disease. Dogs who have hip dysplasia and are over weight are at extremely high risk for chronic arthritis in the hips. Proper weight control should be obtained through proper exercise and dietary management. If your pet is over weight, please consider proper weight control to minimize these risks.

Proper Exercise: If your dog has hip dysplasia you should limit him or her to moderate exercise such as swimming and long walks. High-intensity activity should be of short duration and should only be allowed after an adequate warm-up period.

Anti-inflammatory substances: There are many nonsteroidal anti-inflammatory medications (NSAIDs) available for use in dogs. However, all of these medications must be used with caution, as the pharmacokinetics are largely unknown and overdosage may result in severe gastrointestinal ulceration (the Senior Dogs Project's web site gives many examples of side effects caused by the popular drug Rimadyl.) NSAIDs should never be given without the specific recommendation of a veterinarian. Most NSAIDs interfere with glycosaminoglycan synthesis in the joint fluid and therefore should not be used for extended periods of time. In general, NSAIDs should be reserved for acute flare-ups of pain, but should not be used for long term management due to the potential for gastrointestinal side effects and continued joint breakdown.

A alternative to medical treatment may be the use of a nutritional supplement, such as Arthrix for Dogs and Cats. Arthrix is made up of the raw materials which are the building blocks for cartilage and joint fluid. Extended use of this product is very safe and offers support in a high percentage of dogs. In addition, it may help to maintain joint health in younger animals which benefits your pet on the long run.

¹Most of the information contained on this page was obtained from the chapter "Management of Joint Disease" in Small Animal Surgery by Theresa Fossum, et al, copyright 1997 and "Handbook of Small Animal Orthopedics and Fracture Treatment" by Brinker, Piermattei, and Flo.

Feline Hip Dysplasia¹

CLICK HERE for a Chart of Common Feline Joint Diseases

Hip dysplasia is an inherited trait involving multiple gene pairs - it is not congenital (meaning an animal is not born with it). The condition develops over time from instability in the hip joint which results from an improper fit of the femoral head (ball-like structure) into the acetabulum (hip socket). This instability, called hip joint laxity, results in abnormal weight bearing within the hip joint. From this, secondary changes and remodeling occur in an effort to stabilize the joint or avoid bone-on-bone contact. When cartilage disintegrates, from abnormal wear, the femoral head and acetabulum rub together with every step causing pain and eventual osteoarthritis.

1. Femur

2. Femoral Head (ball like structure)

3. Acetabulum (hip socket)

What are the symptoms of feline hip dysplasia?

It has been suggested that cats with feline hip dysplasia (FHD) are not in pain. Well, unless you can talk directly to your cat, and he can ANSWER you, how can you know for sure? Cats are rather stoic creatures and it is speculated that they hide or mask their pain well. Out in the wilds if a cat showed pain by limping or moving slowly, he would appear vulnerable and be an immediate target for predators. Our domestic cats are still driven by natural instincts that tell them NOT to limp or not to move too slowly. There may be a gradual decrease in certain movements or particular activities that cause pain. For example, a cat in pain may not jump as high as usual, or it may move more and more slowly over time. These may be symptoms that most people simply would not notice or would attribute to other things. The gradual lack of movement may go undetected until one day - perhaps years from the onset of pain - the disease has progressed so that it becomes quite obvious with limping, not climbing, not jumping or the inability to go up stairs. Even then, because onset has been so gradual and there was not a drastic change in behavior from one day to the next some people may still not realize there is a problem.

Other symptoms that may indicate hip dysplasia include: continued dislike of being picked up, carried or being stretched as done at shows, yowling or grumbling when lifted or handled, a lack of motivation to move, stiffness, lameness, sensitivity to touch in the hindquarters, or even a popping sound coming from the back legs with each step. Also seen as possibly associated with dysplastic felines: early rapid growth and weight gain and hips that are noticeably narrower than the shoulders (lean, narrow bodies as opposed to broad, sturdy bodies). In addition, an association between medial patella luxation and hip dysplasia has been found. (See FHDA Library, abstract by Gail Smith, VMD, et.al.) Further information on Dr. Smith's findings can be found in in an article published in the Journal of the American Veterinary Medical Association, Vol 213, No.10, November 15, 1998 called "Relationship between degenerative joint disease and hip joint laxity by use of distraction index and Norberg angle measurement in a group of cats".

Some helpful links to Patellar Luxation sites and information are listed below. Note just as there is far more information on HD in canines than cats, the same holds true for Patellar Luxation.

http://www.prodogs.com/chn/ofa/patellar.htm

http://home.swipnet.se/~w-33901/patella.html

http://www.lhasa-apso.org/articles/luxation.htm

http://www.veterinarymall.com/info/patella.html

These signs and symptoms don't always mean hip dysplasia, but if one or more are observed over time, consult your veterinarian. X-rays may be indicated. Since feline hip dysplasia is still relatively new to the veterinary community, be sure to mention FHD to your vet. Some vets appreciate seeing information on new animal research so you might consider giving your vet the FHDA web site address.

NOTE: X-rays sent to OFA are evaluated by board-certified veterinary radiologists; you may wish to request that your vet go ahead and send the film to OFA for further evaluation.

Arthritis in Dogs and Cats

If you are interested in the biochemical cause of arthritis, please CLICK HERE

It is estimated that one in five of the 80 million adult dogs and cats in the United States suffer from arthritis to some degree, according to James Roush, doctor of veterinary medicine at Kansas State University. There are some signs owners should look for to tell when your pet experiences pain from arthritis.

"First, you will see some sort of lameness or reluctance to get up or move around," Roush said. "Owners will often note that he or she doesn't jump on or off the bed as often. The other things you may see are swelling in the joints, and heat or pain when you touch the joints. Dogs also won't like their legs moved."

There are two common reasons animals develop arthritis. The most common reason for skeletal or joint diseases are congenital, which means the diseased joints form because the dog or cat inherits imperfect physical traits, Roush said.

Hip and elbow dysplasia, degenerative joint diseases, are examples of common congenital diseases in large-breed dogs. Large dogs have big skeletal frames and grow faster than normal, which can cause stress on the joints, leading to arthritis.

The second most common cause of arthritis in dogs or cats is damage to joints from accidents. Damage to ligaments in knees and shoulders are common joint injuries received from accidents. In time, this can lead to inflamed joints and arthritic symptoms.

Your pet may not be able to tell you if he or she is in pain: dogs and cats don't moan and complain about their aching joints! This slowly progressive disease starts with almost undetectable discomfort, and may progress to the point that the animal refuses to stand, go outside when nature calls, or even eat. Similar to an aging person, the joints of our four-legged friends undergo aging changes as well. The joint fluid is not produced in enough quantity and the bones and ligaments begin to degenerate and become inflamed. The range of motion of these joints diminishes. The incidence of arthritis is most common in larger breed dogs but can affect small dogs and cats as well.