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Erosive, Immune-Mediated Polyarthritis in Dogs (Joint Cartilage Damage) in Dogs

Occurrence: very rare
Location of illness: Legs

Author: Dr. med. vet. Gisa Löwe | Last modified: 06.11.2025

Erosive, immune-mediated polyarthritis in dogs is an inflammatory joint disease caused by the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body., leading to damage to the joint cartilage.

The most important facts at a glance

Erosive, immune-mediated polyarthritis in dogs is an autoimmune disease in which the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. attacks the joints, leading to the destructionDestruction means "demolition." In medicine, it refers to the destruction of cells, tissues, organs, or body parts. The growth of malignant Tumors is also usually accompanied by destruction of the surrounding tissue. of joint cartilage. This disease occurs when the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. can no longer distinguish between its own cells and foreign cells, with genetic factors, environmental conditions, and infections potentially playing a role. Symptoms include lameness, stiff gait, reluctance to move, and joint pain. DiagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is made through clinical examination, imaging techniques such as X-rays and MRI, and laboratory tests. Treatment aims to reduce inflammation and modulate the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body., using anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. and immunosuppressants. PhysiotherapyVeterinary physiotherapy encompasses a range of treatment methods aimed at improving the mobility and well-being of animals through exercise, massage, and other manual techniques. and supplements can be supportiveSupportive refers to supportive treatments that aim to alleviate symptoms and improve quality of life without directly treating the underlying cause of the disease.. The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on the severity of the disease and the response to therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions.; early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and consistent treatment are crucial for a good quality of life. PreventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. is difficult, but a balanced diet and regular exercise can reduce the risk. Research focuses on the immunological mechanisms, genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases., and new therapies such as monoclonal antibodies. Non-invasive diagnostic techniques are also being developed to improve early detection.

Causes

Erosive, immune-mediated polyarthritis is one of the autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus. in which the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. mistakenly attacks the body’s own structures. In this particular form of arthritisArthritis is an inflammation of the joints that can cause pain, swelling, stiffness, and limited mobility. There are many forms of arthritis, including rheumatoid arthritis and osteoarthritis., the joints are affected, with the inflammation leading to destructionDestruction means "demolition." In medicine, it refers to the destruction of cells, tissues, organs, or body parts. The growth of malignant Tumors is also usually accompanied by destruction of the surrounding tissue. of the joint cartilage. Cartilage is an important tissue that covers the ends of the bones in a joint and serves as a buffer and sliding surface.

Immune-mediated diseases occur when the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. is no longer able to distinguish between the body’s own and foreign cells. Genetic factors, environmental conditions, and infections can contribute to the dysregulation of the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body.. In dogs with erosive polyarthritis, misdirected immune cellsImmune cells are specialized cells of the immune system that help to identify and fight pathogens and foreign substances. These include leukocytes such as lymphocytes (T cells and B cells), macrophages, and dendritic cells. attack the joint structures, leading to inflammation and eventual erosion of the cartilage.

Causes of the disease include genetic predispositions, which may be more common in certain dog breeds. Infections and environmental factors, such as stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. or chemical exposureExposure refers to the Contact with or subjection to certain substances, environmental factors, or pathogens. In veterinary medicine, this can include Contact with toxins, allergens, or infectious agents that can cause health problems in dogs and cats., can also act as triggers. However, the exact cause of the disease is often multifactorialMultifactorial refers to conditions or diseases that arise from the interplay of several causes or risk factors. In dogs and cats, these can be genetic predispositions, environmental influences, and nutritional factors that together lead to health problems. and not always clearly identifiable.

Symptoms

Very common symptoms:

Common symptoms:

The symptoms of erosive, immune-mediated polyarthritis are varied and can vary in severity. The most common symptoms are lameness, swelling, and pain in the affected joints. Affected dogs often show reduced mobility and avoid activities that cause them pain.

In addition to lameness, there may be stiffness of the joints, especially after periods of rest or in the morning. Dogs with this condition may also show general symptoms such as fever, lethargy, and loss of appetite. In advanced stages, the inflammation can lead to permanent joint damage, which significantly impairs the dog’s quality of life.

Diagnosis

The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of erosive, immune-mediated polyarthritis is based on a combination of clinical examination, imaging procedures, and laboratory tests. The veterinarian will first take a thorough historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits. and examine the dog for typical symptoms of the disease.

X-rays of the affected joints can help identify typical changes such as joint space narrowing and cartilage erosions. In addition, ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. examinations and magnetic resonance imaging (MRI)Magnetic resonance imaging is an imaging technique that uses strong magnetic fields and radio waves to create detailed images of the inside of the body. It is used in veterinary medicine to diagnose diseases of the brain, spine, and other organs. can be used to obtain more detailed information about the condition of the joints.

Laboratory tests include blood tests to check for inflammatory markers and autoantibodies that may indicate an immune-mediated disease. A joint fluid analysis can also be performed to detect inflammatory changes directly in the affected joint.

Therapy

The treatment of erosive, immune-mediated polyarthritis aims to reduce inflammation, relieve pain, and modulate the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body.. An important pillar of therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. is anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. such as non-steroidalNon-steroidal refers to medications or substances that are not steroids and often have anti-inflammatory, analgesic, or antipyretic effects. They are used in dogs and cats to treat Pain and Inflammatory conditions. anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. (NSAIDsNSAID (non-steroidal anti-inflammatory drug) stands for non-steroidal anti-inflammatory drugs, a class of medications used to relieve pain, reduce inflammatory conditions, and lower fever without using steroidal agents. They are a commonly used pain reliever in veterinary medicine.), which help control pain and inflammation.

In addition, immunosuppressants can be used to dampen the overactive immune responseAn immune response is the immune system's reaction to foreign substances (antigens), such as microorganisms or proteins. It involves a series of processes aimed at recognizing, fighting, and eliminating these antigens.. These drugs are important to prevent the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of joint damage. In some cases, the veterinarian may also prescribe corticosteroidsCorticosteroids are a class of steroid hormones that occur naturally in the body and can also be produced synthetically. They have anti-inflammatory and immunosuppressive properties and are used in veterinary medicine to treat a variety of conditions. to treat acuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. flare-ups of the disease.

In addition to drug therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions., physiotherapyVeterinary physiotherapy encompasses a range of treatment methods aimed at improving the mobility and well-being of animals through exercise, massage, and other manual techniques. can be helpful to maintain joint mobility and prevent muscle atrophyMuscle atrophy is the loss of muscle mass that can be caused by inactivity, malnutrition, or certain diseases. In dogs and cats, muscle atrophy can occur due to chronic diseases, aging, or after prolonged immobilization.. A balanced diet and supplements containing omega-3 fatty acids and glucosamine can also be supportiveSupportive refers to supportive treatments that aim to alleviate symptoms and improve quality of life without directly treating the underlying cause of the disease..

Prognosis and follow-up care

The prognosis for dogs with erosive, immune-mediated polyarthritis depends on the severity of the disease and the response to treatment. With early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and consistent therapy, many dogs can maintain a good quality of life and the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of the disease can be slowed down.

However, the disease can be chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. and often requires lifelong treatment and monitoring. Without appropriate therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions., severe joint damage can occur, which can significantly limit the dog’s mobility and reduce its quality of life.

Prevention

Since the exact cause of erosive, immune-mediated polyarthritis is often multifactorialMultifactorial refers to conditions or diseases that arise from the interplay of several causes or risk factors. In dogs and cats, these can be genetic predispositions, environmental influences, and nutritional factors that together lead to health problems., there is no specific preventive measure that can completely prevent the disease. However, some general measures can reduce the risk of developing the disease.

A balanced diet and a healthy weight can help support joint health and avoid overstressing them. Regular exercise is also important to maintain joint function, but should be adapted to the needs of the dog to avoid overexertion.

Regular veterinary examinations are crucial to detect early signs of joint disease and take action if necessary. In dogs with a genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases. to autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus., close monitoring and early intervention can be beneficial.

Outlook on current research

Research on erosive, immune-mediated polyarthritis in dogs is currently focused on understanding the exact immunological mechanisms that lead to this disease. A particular focus is on the role of various immune cellsImmune cells are specialized cells of the immune system that help to identify and fight pathogens and foreign substances. These include leukocytes such as lymphocytes (T cells and B cells), macrophages, and dendritic cells. and the cytokines they produce, i.e. signaling molecules that regulate inflammation in the body. Researchers are trying to find out which specific cell types and signaling pathways are overactive in the joints of affected dogs and lead to the observed destructionDestruction means "demolition." In medicine, it refers to the destruction of cells, tissues, organs, or body parts. The growth of malignant Tumors is also usually accompanied by destruction of the surrounding tissue. in the cartilage. These findings could help to develop targeted therapeutics that specifically act on these signaling pathways and thus stop the inflammation and progressive cartilage damagecartilage damage are injuries or wear and tear of the cartilage tissue that covers and protects joints, ribs, ears, and other body parts. Damage can be caused by injuries, wear and tear, or conditions such as arthritis, leading to Pain and restricted movement..

Another exciting area of research is the genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases. to this type of arthritisArthritis is an inflammation of the joints that can cause pain, swelling, stiffness, and limited mobility. There are many forms of arthritis, including rheumatoid arthritis and osteoarthritis. in dogs. Scientists are investigating which genetic markers or mutations are associated with a higher risk of developing the disease. By identifying such genetic factors, researchers hope to support breeding programs that can reduce the risk of this disease. In addition, genetic tests could be developed to identify at-risk dogs early on.

Current studies are also exploring the use of newer biological therapies, such as monoclonal antibodies, that block specific inflammatory mediators. These therapies could enable more precise treatment by modulating the immune responseAn immune response is the immune system's reaction to foreign substances (antigens), such as microorganisms or proteins. It involves a series of processes aimed at recognizing, fighting, and eliminating these antigens. without suppressing the entire immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body.. InitialInitial means beginning or at the start. In medicine, it can refer to the first symptoms of a disease or the first phase of a treatment process. clinical trials have already shown promising results, with affected dogs showing a significant reduction in inflammatory symptoms and an improvement in quality of life.

In addition, the role of diet and supplements in supporting joint health and reducing inflammation is also being investigated. Omega-3 fatty acids, glucosamine, and chondroitin are some of the supplements being studied in various trials to assess their potential beneficial effects on the joint health of dogs with immune-mediated polyarthritis.

Another aspect of the research focuses on the development of non-invasive diagnostic techniques to detect the disease early and monitor its progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms.. Imaging techniques such as magnetic resonance imaging (MRI)Magnetic resonance imaging is an imaging technique that uses strong magnetic fields and radio waves to create detailed images of the inside of the body. It is used in veterinary medicine to diagnose diseases of the brain, spine, and other organs. and advanced ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. techniques are being tested to improve accuracy and reliability in assessing joint damage. These technologies could enable earlier diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and individually tailored therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. planning in the future.

Frequently asked questions (FAQs)

What is erosive, immune-mediated polyarthritis in dogs? This disease is an autoimmune disorder in which the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. attacks and destroys its own joints, leading to inflammation and damage to the joint cartilage. It is a chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. condition that can lead to pain and limited mobility.
What symptoms do dogs with this condition show? Dogs with erosive, immune-mediated polyarthritis often show symptoms such as lameness, swelling in the joints, stiffness, especially after resting, and possibly a reduced activity level. In some cases, fever and loss of appetite may also occur.
How is this condition diagnosed? DiagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. requires a thorough clinical examination by a veterinarian, blood tests to identify inflammatory markers, and imaging techniques such as X-rays or MRI to assess the damage to the joints. A joint fluid analysis can also be performed to determine the number of inflammatory cells.
What treatment options are there? Treatment focuses on controlling symptoms and slowing the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of the disease. This includes administering anti-inflammatory medications, immunomodulatorsImmunomodulators are substances that affect the immune system by increasing or decreasing its activity. They are used in dogs and cats to treat autoimmune diseases, allergies, or as cancer therapy., and occasionally physiotherapyVeterinary physiotherapy encompasses a range of treatment methods aimed at improving the mobility and well-being of animals through exercise, massage, and other manual techniques.. In some cases, surgical interventions may also be necessary to repair severe joint damage.
Can diet help with treatment? A balanced diet rich in omega-3 fatty acids and joint-supporting supplements such as glucosamine and chondroitin can help reduce inflammation and promote joint health. It is important to talk to a veterinarian about the best nutritional strategy for the affected dog.
Can this condition be cured? Currently, there is no cure for erosive, immune-mediated polyarthritis, but with the right treatment, the symptoms can be controlled and the dog’s quality of life can be significantly improved. Early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and individually tailored treatment are crucial for managing the disease.
Which dog breeds are most commonly affected? While the disease can occur in any dog breed, some breeds may be genetically more susceptible to autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus.. Breeds such as the Shetland Sheepdog, Beagle, and Doberman Pinscher are mentioned more frequently in some studies, but research in this area is not yet complete.
How can I help my dog with this condition? In addition to medical treatment, it is important to control the dog’s weight to minimize stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. on the joints. Regular, gentle exercise and physiotherapyVeterinary physiotherapy encompasses a range of treatment methods aimed at improving the mobility and well-being of animals through exercise, massage, and other manual techniques. can also be helpful. In addition, stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. should be avoided, as it can further burden the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body..
How often should a dog with this condition be examined by a veterinarian? Dogs with erosive, immune-mediated polyarthritis should be examined regularly by a veterinarian, ideally every three to six months, to monitor the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of the disease and adjust treatment if necessary.
Are there new treatment approaches in development? Yes, research is focused on new biological therapies that specifically target the immune mechanisms that drive inflammation in this disease. These new treatments could offer more targeted and effective options for affected dogs in the future.