By Dr. Becker
Today I want to talk about different types of arthritis in pets. Many pet parents don’t realize there’s more than one type of arthritis that can affect a dog or cat.
- There’s the type of arthritis everyone is familiar with, which is called osteoarthritis or degenerative joint disease. This type of arthritis is commonly seen in older animals.
- There’s septic arthritis, which is inflammation and degeneration of a joint or joints caused by infection.
- And there’s also another type of arthritis called immune-mediated polyarthritis, which can take many forms and occurs when a pet’s immune system attacks the joints of the body.
Osteoarthritis/Degenerative Joint Disease (DJD)
The type of arthritis most pet guardians are familiar with is osteoarthritis, also known as degenerative joint disease (DJD) or degenerative arthritis. This form of the disease is characterized by progressive, long-term, permanent deterioration of the cartilage surrounding the joints. “Arthritis” is the term used for inflammation of the joints; “osteoarthritis” describes chronic joint inflammation caused by deterioration of the joint cartilage.
Primary degenerative joint disease is generally considered to be of unknown cause. However, there are many causes for secondary DJD, including trauma, abnormal wear and tear on the joints and cartilage, or an inherited defect present at birth such as hip dysplasia.
Other causes of secondary DJD include abnormal development of the hip or elbow; dislocation of the kneecap or subluxation of the knee cap or shoulder; osteochondrosis dissecans (OCD), a condition in which a flap of cartilage develops abnormally within the joint; and also obesity, which increases stress on the joints. Animals with diabetes, those on prolonged steroid therapy, and dogs with excessive looseness (laxity) of the joints are also at greater risk for DJD.
Symptoms of osteoarthritis vary and include reduced activity level, occasional lameness, and a stiff gait that gets worse after exercise, long periods of activity, or in cold weather.
Diagnosis and Treatment of Osteoarthritis
In diagnosing osteoarthritis, your veterinarian will take a history of symptoms and perform a physical exam to evaluate your pet’s range of motion and gait, and to check for a joint deformity, or swelling or pain in the joints.
Treatment for DJD is aimed at controlling or alleviating the symptoms rather than curing the disease. Sometimes surgery can help relieve symptoms and slow the progression of joint deterioration. This can include a reconstructive procedure, joint removal or replacement, or surgical removal of aggravators of bone or cartilage fragments in a joint, sometimes known as “joint mice.”
Physical therapy is an absolute must for pets with DJD and should be designed to maintain and increase joint strength, muscle tone, and range of motion. This can be accomplished with therapeutic exercises, swimming, and massage.
Pain can sometimes be managed with cold and heat therapy, and acupuncture. But especially as a pet ages, anti-inflammatory and pain medications are often prescribed to manage day-to-day pain. However, I’ve had very good success using natural anti-inflammatory agents like esterified fatty acid complex, fish oil, turmeric, and proteolytic enzyme therapy to reduce or eliminate the need for daily non-steroidal anti-inflammatory drugs (NSAIDs) for many of my patients.
Chondroprotective Agents for Pets with Osteoarthritis
Chondroprotective agents (CPAs) or joint-protecting agents are also a must. Although CPAs don’t manage joint pain, they do slow the rate of degeneration, which is critical. It’s always shocking to me to hear how many animals are on drug-based pain medication. These drugs can certainly play an important role in maintaining a pet’s quality of life, but they do nothing to address the root cause of the problem, which is cartilage degeneration. That’s why it is vitally important that all animals with osteoarthritis be on CPAs.
The form, dose, and type of CPA your veterinarian prescribes will be based on your pet’s medical circumstances. For example, many of my patients with inflammatory bowel disease (IBD) also have arthritis. They can’t take oral supplements without significant gastrointestinal side effects. For these patients, I use an injectable joint-support product to bypass the gut, such as acetyl-d-glucosamine or polysulfated glycosaminoglycans, otherwise known as Adequan.
Some of my patients are allergic to fish, beef, or pork. Using chondroitin or glucosamine from these sources can be aggravating to their systems. So for these pets, I choose a supplement like methylsulfonylmethane (MSM) or eggshell membrane. Eggshell membrane is not eggshell calcium – it’s a different product. I might also consider using cetyl myristoleate (CMO).
I have found that each animal responds differently to CPAs. Sometimes, rotating through a variety of products is necessary before we find the one that is most beneficial for a pet’s specific symptoms. I recently treated a cat that didn’t respond to the first three products we tried. But then we put her on a combination of Perna mussel (also called green-lipped clam) as her CPA, plus bromelain (a proteolytic enzyme) as her anti-inflammatory, and it did the trick.
It’s important to monitor your pet’s symptoms on an ongoing basis, because osteoarthritis progresses over time. Your pet’s body is dynamically changing, and her arthritis protocol will need to change as well to meet her body’s evolving requirements. You should bring your pet for a wellness check with your veterinarian at least twice a year to review the status of her health, but also to check the range of motion in her joints, the muscle mass she is either gaining or losing, and to make adjustments to her protocol as necessary to ensure her quality of life is optimal.
I have always found that a multimodal approach to managing osteoarthritis is critical for slowing down its progression. Incorporating maintenance chiropractic, massage, acupuncture, daily stretching and mild exercise – like swimming, which is perfect – along with an oral protocol to manage pain and inflammation will yield the very best results for an arthritic pet.
Septic arthritis is a type of joint inflammation caused by a bacterial or, less often, fungal infection. This type of arthritis typically affects a single joint, but there can be more than one joint involved in some cases.
Septic arthritis differs from typical arthritis in that the usual form of the disease doesn’t involve infection of the joint fluid. Regular arthritis is characterized by inflammation of one or more bone joints, whereas septic arthritis is inflammation plus the presence of a disease-causing organism within the fluid surrounding the joint.
Septic arthritis is most commonly seen in male dogs between 4 and 7 years of age, and predisposed breeds include Dobermans, German Shepherds, and Labradors. The condition is relatively rare in cats.
Pets with compromised immune systems or diabetes are at higher risk for infections of all types, including septic arthritis. The disease can occur after a traumatic joint injury, where the joint is exposed to the environment or contaminated by potential pathogens.
An opportunistic infection can develop after a surgical procedure or when pathogens travel to the joints through the bloodstream from systemic infection. Infection elsewhere in the body in a dog or cat can sometimes end up inside joint fluid, which can also cause septic arthritis.
Symptoms of septic arthritis include pain, fever, lethargy, lack of appetite, joint swelling, lameness of the affected limb or limbs if there are several joints involved, and the joint can also be warm to the touch. Sometimes pets are not able to move or walk well and are noticeably uncomfortable.
Diagnosis and Treatment of Septic Arthritis
Your veterinarian will want to know if your pet has sustained a recent injury or has had a recent surgery. A physical exam will help determine whether one or multiple joints are involved. Lab tests will include a complete blood count, a biochemistry profile, and a urinalysis. X-rays of the affected joint will be taken to see what changes may have occurred due to the inflammation. If the infection is chronic, changes in the joint structures will be observed, including destruction of bone, irregular joint space, and abnormal bone formation.
The most important diagnostic test will be an analysis of the fluid taken from the joint. A sample collection will almost always involve sedation or anesthesia. This test can indicate the presence of increased joint fluid in the joint space, as well as changes in the color of the fluid, presence of inflammatory cells within the fluid, and it will also identify the bacteria causing the infection. The joint fluid should also be cultured to confirm the diagnosis of septic arthritis and help identify the best way to treat the infection.
If there is infection elsewhere in your pet’s body and your vet believes there is systemic infection, blood and urine samples should also be cultured to identify the pathogen involved and the best way to treat it.
Once a diagnosis of bacterial infection is confirmed, the appropriate antibiotic will be administered based on the results of culture and sensitivity testing. You’ll want to start your pet on a probiotic at this time as well. If the joint infection is chronic, occasionally surgery is required to remove debris and flush the joint. In this instance, a catheter is usually inserted during surgery to allow drainage from the contaminated joint to occur afterwards for several days.
Arthroscopy, which is an endoscope inserted into the joint through a small incision, is also sometimes used to allow visualization of the interior surface of the joint. In certain cases, it can also be used to treat joint infection. Obviously, identifying and treating the source of the infection is crucial for successful treatment of septic arthritis.
Immune-Mediated Polyarthritis (IMPA)
Probably the most confusing type of arthritis for pet owners to understand is the immune-mediated variety. In this type of arthritis, joint inflammation is caused by the immune system attacking the body -- in this case, a joint or multiple joints. “Poly” simply means that multiple joints are involved.
When an animal has IMPA, white blood cells from the immune system, called neutrophils, invade the joints of her body. The normal job of neutrophils is to fight bacteria and other pathogens that invade the body by releasing large amounts of irritating substances in the surrounding tissue. In immune-mediated arthritis, the irritating substances from the neutrophils are released into the joint, causing swelling, pain, and a host of other symptoms.
Immune-mediated polyarthritis can be either erosive or non-erosive. In the non-erosive form, there is no destruction of bone or cartilage. In erosive IMPA, there is bone and cartilage destruction in one or more affected joints. The erosive type is very similar to rheumatoid arthritis in humans. Fortunately, erosive IMPA is rare in pets, accounting for less than one percent of all reported cases. The non-erosive form of the disease can occur in dogs regardless of breed, size, or gender. It is most common in dogs between 4 and 6 years of age, but is rare in cats.
Symptoms can include a stiff gait, lameness, trouble standing on a joint or joints, and spinal pain. There can also be signs of illness that include loss of appetite, weight loss, fever, lethargy, and enlarged lymph nodes.
About 25 percent of dogs with the disease have systemic signs with little or no obvious joint-related symptoms. About 20 percent of dogs with fever of unknown origin are ultimately diagnosed with immune-mediated polyarthritis. It should always be considered as a possible factor in dogs with fever unrelated to another illness. Most cases of immune-mediated polyarthritis in dogs are considered idiopathic in origin – meaning we can’t determine an underlying reason for the condition.
Non-Erosive Immune-Mediated Polyarthritis
Non-erosive idiopathic IMPA is separated into four subtypes depending on whether there are other concurrent diseases. Treatment actually depends on the subtype that’s identified.
IMPA is frequently diagnosed in dogs suffering from systemic lupus erythematosus or SLE. Treatment of SLE polyarthritis is similar to the treatment of idiopathic forms, which in traditional veterinary practice means administering immunosuppressive and immunomodulating drugs. If other organs are involved, treatment must also address those clinical signs.
There is another form of non-erosive IMPA called polyarthritis-meningitis syndrome in which steroid-responsive meningitis occurs with polyarthritis in young, male, medium-to large-sized dogs. Treatment of the two conditions is similar, but the syndrome is important to recognize since recurrence or neurologic damage can occur without proper treatment.
There is also a condition known as polyarthritis-polymyositis syndrome, which occurs most commonly in young to middle-aged spaniel breeds. Traditional treatment is similar to that of idiopathic IMPA, but the presence of concurrent muscle involvement makes the situation potentially more complicated.
Other causes of IMPA are drug-induced polyarthritis and vaccine-associated polyarthritis.
Administration of certain medications, especially sulfonamides, antibiotics – lincomycin, erythromycin, cephalosporins, phenobarbital, and penicillins – as well as the anti-seizure drug phenobarbital, have been implicated in the development of immune-mediated polyarthritis in Dobermans and other large-breed dogs. Treatment involves discontinuing the drug, with improvement generally noted within 24 hours, and a complete recovery within 2 to 5 days of drug withdrawal.
Vaccines have been implicated in the development of IMPA, and when this occurs, typically we begin noticing symptoms within 30 days of vaccination. But that’s not always the case. Canine distemper antigens have been found in immune complexes from the joints of dogs with the erosive form of IMPA. According to the literature, most vaccine-associated IMPA cases are self-limiting and may require a short course of immunosuppressive treatment. In my opinion, animals that have had adverse vaccine reactions, including vaccine-induced IMPA, should receive no further vaccinations of any kind.
There is yet another form of non-erosive IMPA called breed-specific polyarthritis that has been reported in adolescent Akitas that may also have concurrent meningitis or other organ involvement. Chinese Shar-Peis can develop “Shar-Pei fever” or “swollen hock syndrome.” In both these types of immune-mediated polyarthritis, the prognosis is often poor due to the presence of other concurrent conditions or diseases.
Erosive Immune-Mediated Polyarthritis
The two main types of erosive IMPA are idiopathic and a form of the disease that affects Greyhounds exclusively.
Idiopathic erosive IMPA is seen more commonly is smaller breeds of both sexes, with an average age of 2 to 6 years. Symptoms include stiffness, intermittent lameness, swelling of a single or multiple joints, fever, lethargy, loss of appetite, and lymph node enlargement. Erosive polyarthritis is a progressive disease that results in connective tissue degeneration and increasing joint instability.
Traditional treatment involves the use of immunosuppressive, disease-modifying, or anti-inflammatory drugs. Therapy must be administered for the life of the animal. Long-term prognosis for these cases is unfortunately poor.
Erosive polyarthritis in Greyhounds is a sporadic disease that affects young dogs between 3 and 30 months of both genders. This form of IMPA progresses more slowly than idiopathic erosive polyarthritis and doesn’t do as much damage. Traditional treatment is similar to idiopathic erosive polyarthritis.
Diagnosis and Treatment of Erosive IMPA
The definitive test for IMPA is a joint tap and analysis of the fluid sample. The joint tap may require that your pet be sedated, especially because multiple joints will probably be tapped. Since immune-mediated polyarthritis often occurs secondary to other diseases or conditions, additional diagnostic tests should be performed. A minimum test set will include a urinalysis, urine culture, and X-rays to identify whether the disease is erosive or non-erosive. Sometimes an ultrasound can be helpful as well.
As you can see, it’s very important to get a correct diagnosis of the type of arthritis that’s occurring in your pet.
Immune-mediated disease is an overreaction of your pet’s immune system, and using any type of natural immune support or immune stimulant would be extremely detrimental and could actually exacerbate your pet’s condition. Working with a holistic veterinarian and a rehab therapist will afford you the best opportunity to select the correct protocol for your pet’s specific type of arthritis.
In all cases of arthritis, it’s important to feed an anti-inflammatory diet, as your pet is suffering from inflammatory pain. The food you feed will either exacerbate the pain or help ameliorate it. Foods either heal or harm. Feeding a grain-free, low-carb diet is important, as well as incorporating an abundance of antioxidant-rich veggies and fruits. I recommend avoiding feeding vegetables in the nightshade family – that means no potatoes, tomatoes, or peppers – as these foods are pro-inflammatory. Ideally, a balanced, species-appropriate fresh food diet is best for arthritis patients.
I also recommend reducing unnecessary vaccines and insecticide applications for animals fighting chronic inflammation. Talk to your holistic veterinarian about vaccine titers and alternatives to the ingestion or topical application of pesticides and insecticides.