Knee Pain in Dogs

Knee pain in dogs can be extremely debilitating as it’s very difficult to take the pressure off that area of the body. Knee pain in dogs can take the form of injuries, genetic or hereditary diseases, and even size. For example, smaller dogs are more predisposed to luxated patellas.

Common Symptoms:

  • Lameness
  • Limping
  • Fever
  • Loss of appetite
  • Weight loss
  • Irritability
  • Reluctance to be touched
  • Licking, chewing, or biting the affected area
  • Muscle Atrophy
  • Sleeping More

Causes of Knee Pain

Cranial Cruciate Ligament Tear

A Cranial Cruciate Ligament Tear is an extremely painful yet very common injury among dogs. One of the most important stabilizers within the canine knee (stifle) joint, the middle joint of the back leg, is the cranial cruciate ligament. The CrCL is also known as the anterior cruciate ligament in humans (ACL). The meniscus is a cartilage-like organ that lies between the femur (thigh bone) and the tibia (shin bone). It performs a variety of functions in the joint, including shock resistance, location sensing, and load-bearing, and it may be affected if the CrCL ruptures. CrCLD is most often caused by a variety of causes, including ligament degeneration, obesity, poor physical health, genetics, conformation (skeletal structure and configuration), and breed. Ligament damage in CrCLD happens as a result of progressive degeneration over months or even years, rather than as a result of severe, sudden damage to an otherwise stable ligament which is very rare.


  • Rest and anti-inflammatory medications for dogs under 30 lbs, which is followed by exercise and weight loss if needed.
  • Surgery to provide stability for the joint.
  • Physical rehabilitation included icing the dog’s joint and performing gentle range exercises.
  • Stem cell therapy.
Immune-mediated Polyarthritis

Polyarthritis is the inflammation and swelling of joints making them painful and swollen that may cause dogs difficulty walking. Immune-mediated Polyarthritis refers to arthritis that’s a direct result of abnormal immune response by the body directed at the joints. This can come from either an auto-immune disorder or infection. Signs include overall joint pain, fever, loss of appetite, swelling of multiple joints, lameness. To diagnose this, a thorough physical examination and a variety of laboratory examinations, including blood and urine tests and urine culture, are common tests used to identify a possible origin of an internal infection.


  • Generally treated with immunosuppressive medications until the lowest dose is found that still manages the disease.
Juxta-articular Fractures

Juxta-articular fractures are fractures that occur near a joint surface and they may be intra- or extra-articular. Salter III and IV fractures, as well as humeral and femoral supracondylar fractures, are examples of intra-articular fractures. The bulk of juxta-articular fractures occur in dogs with immature skeletons. This type of fracture can cause immediate changes in joint anatomy, impacting joint cohesion, causing discomfort, and disrupting joint motion. Because of the short length of one of the bone segments, the possible small size of the bone, the relative softness of bone, and the involvement of articular surfaces close to the fracture site or involved in the fracture, these fractures are difficult to treat. Treatment goals include restoring joint flexibility and congruity, minimizing degenerative articular modifications, and maintaining joint efficiency.


  • Internal plating of the fracture via surgery.
  • External coaptation which is the use of bandages, casts and splints to stabilize the fracture.
  • Transarticular external stabilization is a procedure that involves positioning an external skeletal attachment mechanism above and below a joint and connecting it with rigid bars to minimize joint mobility.
Luxated Patella

A luxated patella is a very painful condition for dogs in which the knee cap moves out of its normal position. Small and toy breed dogs are more susceptible to this condition and more likely to have a genetic predisposition for a luxating patella. A dog owner may see their dog suddenly skip while walking or see them run on three legs and then the dog is completely back to normal. Patellar luxation can be classified into many degrees or classes, ranging from mild luxation, in which the kneecap only luxates when stress is applied directly to it, to moderate luxation, in which the kneecap sticks out regularly, to extreme luxation, in which the kneecap has dislocated the rest of the time. One or both kneecaps can luxate in affected dogs, often to varying degrees. Some dogs can live their entire life with this condition and not be affected long term while it can cause permanent, painful issues later on for other dogs because the inner side of the groove in the femur may wear down. Dogs with luxating patellas are also predisposed to other injuries such as torn cruciate ligaments and possibly arthritis on the supporting limbs. There are four grades of a luxated patella to take into account:

  • Grade I: Manual pressure causes the kneecap to dislocate from its natural location, but it quickly recovers when the pressure is relieved. Grade I is typically discovered by chance during a veterinarian’s evaluation and does not show.
  • Grade II: With manual pressure, the kneecap easily moves out of its usual position and stays displaced until it’s manually corrected. Lameness can occur as the patella luxates out of its usual position, and it can be uncomfortable and painful if the cartilage is weakened as a result of repeated luxation.
  • Grade III: The kneecap is disjointed more often than not but can be moved back in place with manual pressure. Although, once that manual pressure is removed, the patella starts to luxate spontaneously. Dogs experiencing grade will experience more pain, discomfort, and lameness as their limb structure changes and/or cartilage damage from repeated luxation.
  • Grade IV: The kneecap is dislocated from its position 100% of the time and does not have the ability to be manually relocated back into place. This results in severe lameness, impaired mobility, and reduced limb function. 


  • Surgery may be performed to hold the patella in its correct location based on the severity.
  • Your vet may teach you how to massage the kneecap back in place.
  • Joint supplements can support knee strength.
Lyme Disease

Lyme disease is not directly a joint-related disease but causes pain. Lyme disease is the most common disease transmitted from ticks although it only shows symptoms in 5-10% of infected dogs. The most notable signs of Lyme disease are recurrent lameness from inflammation of the joints, general discomfortness, and a fever. Lameness from Lyme disease usually only lasts about 3-4 days but often recurs in the same legs or other legs days or even weeks later. Only your veterinarian can diagnose Lyme disease through blood tests, urinalysis, fecal examination, complete blood cell count, x-rays, and possibly fluid drawn from the joints.



Osteoarthritis, also known as Degenerative Joint Disease (DJD), affects both dogs and humans alike and is the most common form of arthritis affecting nearly a quarter of a million dogs worldwide at any given time. It is a progressive, chronic joint condition marked by the weakening of joint cartilage, thickening of the joint capsule, and the forming of new bone around the joint (osteophytosis), both of which contribute to pain and limb dysfunction. The majority of OA in dogs is caused by developmental orthopedic diseases including cranial cruciate ligament disease, hip dysplasia, elbow dysplasia, OCD, and patella (knee cap) dislocation. In a small percentage of dogs, OA develops for no apparent reason and is linked to genetics and age. Bodyweight, obesity, exercise, and diet are all factors that contribute to osteoarthritis. Unfortunately, the damage caused by OA is irreversible but treatment plans help reduce pain and improve quality of life. 


  • Weight loss for overweight dogs can help take pressure off affected joints.
  • Regular moderate exercise helps keep joints healthy.
  • Physical medicine including acupuncture, chiropractic, laser therapy, regenerative medicine, medicinal massage, and physical rehabilitation. 
Osteochondritis Dissecans

Osteochondritis Dissecans (OCD) is a painful abnormality that disrupts the healthy development of bone from cartilage. When OCD happens, a flap of cartilage develops within joints which then causes lameness and joint pain. The most commonly affected joints include the elbow, shoulder, and knee. Dogs with OCD in the shoulder also tend to be male. Factors such as diet, genetics, hormonal imbalance, trauma, growth rate, and joint architecture, can increase the likelihood of developing OCD. Due to its nature, OCD tends to affect larger breeds like Golden Retrievers, Mastiffs, Old English Sheepdogs, Labrador Retrievers, Chow Chows, German Shepherds, Newfoundlands, Bernese Mountain Dogs, Rottweilers, and Standard Poodles. With genetics playing a big role, many vets recommend affected dogs be withheld from breeding. Dogs will start showing signs around 4-7 months of age with many displaying lameness after heavy exercise or long periods of rest. Clinical signs of OCD include limping and lameness in affected legs, vocalization of pain when the affected joint is touched. The affected joint will also be swollen and warm to the touch. Depending on the severity and pain level, dogs may avoid putting any pressure on the affected leg. OCD can affect both legs so determining if one leg is experiencing greater impact can be difficult. Diagnosing this condition primarily includes X-rays, CT scans, or MRIs. 



Osteochondrosis is a disorder that affects the development of cartilage and bones in both medium and large-sized dogs that grow quickly. The premature joint cartilage fractures and splits from the underlying bone in this state in which cysts will develop under the cartilage if fluid occupies the room. Cartilage fragments may come loose from the end of a bone and float about in the joint cavity which causes inflammation in the infected joint and may progress to arthritis and cartilage breakdown, restricting joint motion. Signs that a dog may be suffering osteochondrosis include lameness, fluid buildup within the joint, and joint stiffness. To determine the extent of the damage, a veterinarian might take an x-ray but endoscope surgery can also be done to further identify the damage. Another option is a CT scan.


Osteogenesis Imperfecta

Osteogenesis Imperfecta is also known as brittle bone disease. Osteogenesis Imperfecta is essentially the inability of the body to produce the collagen protein which provides elasticity to the bones. Because of this, affected dogs’ bones lack the ability to withstand impact and pressure causing them to easily break and fracture. Signs of Osteogenesis Imperfecta have reduced bone density, severe joint pain as well as bone and teeth fractures as affected dogs don’t have the Type 1 collagen needed. Other symptoms include difficulty walking, loose joints, stunted growth, weak tendons and muscles, and malformation of bones. They also present joint pain. There’s, unfortunately, no treatment for this condition but vets may prescribe pain medication to help. The occurrence of multiple bone breaks as well as x-rays can give a definitive diagnosis of osteogenesis imperfecta. Blood tests may also be run to see if the levels of vitamin D, phosphorus, calcium, and parathormone are abnormal. 


  • There is no true treatment that heals this disease.
  • Corrective orthopedic surgery may be done for mild cases.

Osteosarcoma is a bone tumor that is malignant and resembles human pediatric osteosarcoma. Limbs are the most often affected but it can still affect other bones like the jaw, hips, pelvis, ribcage, and skull. It’s even possible for it to arise in non-bony tissue like mammary glands and muscle. It’s more often found in large and giant breed dogs such as Great Danes, Rottweilers and Irish wolfhounds. This disease can be quite painful in the joints and lameness is often presented in affected dogs. Pain medication may be given to help with joints and lameness but may only work for about one to two weeks. Swelling of the bone at the tumor site can be observed at this point and is sometimes sore, swollen, and hot to the touch. Amputation is often the recommended treatment to prevent the cancer from spreading but seeing an oncologist is recommended since it can still spread.


  • Amputation of the affected limb to maintain control of the spread of the cancer.
  • Chemotherapy.
  • Radiation therapy.
  • Pain Medication for temporary relief.
Rheumatoid Arthritis

Rheumatoid arthritis in dogs is very similar to that in humans and the diagnosis criteria is very similar, just adapted for dogs. It’s an immune-related arthritis targeting the cartilage in the joints. Multiple joints are often affected at once and dog pain presents lameness from the pain. Symptoms may include recurrent UTIs, lameness, joint swelling, fever limb atrophy, joint pain, tonsillitis, and inability to walk. The causes of Rheumatoid arthritis aren’t exact but since it’s immune-related, some possible causes could be a genetic predisposition, digestive disease, or cancer. Because Rheumatoid arthritis is not common for dogs and the symptoms can vary greatly, it can be difficult to diagnose. The most common symptoms, such as lameness, is a common symptom in many other disorders and they can come and go. Radiographs are usually the most effective way to determine a diagnosis to see the swelling and trouble in the joints. The vet may also opt to do a biopsy of the tissue to test for inflammation.


  • Generally treated with immunosuppressive medications until the lowest dose is found that still manages the disease.
Septic Arthritis

Septic arthritis is a painful disorder caused by the introduction of bacteria or another infectious agent into one or more joints, resulting in debilitating inflammation. Male, large, and giant breed dogs are the most frequently affected, and although septic arthritis may affect dogs of any age, it is most commonly seen in dogs aged 3 to 11 years. Pressure, swelling, and discomfort in one or more joints are all symptoms of septic arthritis. Reduced range of motion in the affected joint(s), as well as fever, lethargy, and a loss of appetite often accompany those prior symptoms. To diagnose, a vet will look at the dog’s complete medical history as well as any injuries that could have caused wounds leading to septic arthritis. They will do a blood test, a physical examination, urinalysis, and a biochemistry profile. Imaging is also used to diagnose septic arthritis in dogs and the vet will test for bacterial infection by taking fluid from a joint which is the most important test during this process


  • IV and oral antibiotics.
  • Lavage (flush) the joint to minimize joint damage.
  • Surgical opening of the joint, removal of abnormal tissue, and copious lavage.
  • Flushing catheter for post-operative flushing.
Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an immune-mediated disease in which a dog’s immune system begins to attack its own tissue. Essentially, the dog’s body produces antibodies to antigens that are found in its body systems and tissues. Some breeds have a greater predisposition to SLE such as medium to large dogs that are over five years of age. This includes the Shetland sheepdog, Old English sheepdog, Beagle, German shepherd, Irish setter, Nova Scotia duck tolling retriever, Poodle, Collie, and Afghan hound. Signs of SLE can peak and slow over a period of time, with signs increasing as the disease progresses. These include lameness that moves from limb to limb, lethargy, fever, enlarged spleen, enlarged lymph nodes, ulcers at mucocutaneous joints (lips), muscle pain (or atrophy), skin abnormalities (such as thinning or loss of hair, ulcers, redness). Factors such as genetic, physiologic, and environmental elements can increase SLE development. 


  • Dependent on which body system is affected:
    • Kidneys: modified prescription diet.
    • Joints: limited and restricted activity.