Hips and Knees
By Dr. Annette Richmond, DVM
Many orthopedic disorders in dogs are subtle and possibly genetic, whereas others are more obvious and may have been caused by a traumatic event.
The most common disorders are hip dysplasia, a luxating patella (floating knee cap), or a ruptured cruciate ligament (a ligament in the knee). Each has a different level of discomfort and hindrance to a dog’s athletic ability. It is important to have pets examined and diagnosed as soon as an abnormality is detected, in order to start appropriate treatment and prevent secondary adverse affects.
The most common breeds to develop hip dysplasia include German Shepherds, Labrador Retrievers, Golden Retrievers, and several other large breeds. Many dogs are born with normal hips but due to their genetic makeup, the joint develops abnormally. A healthy hip depends on properly formed bones and healthy soft tissue structures that hold the femur to the pelvic bone. Hip dysplasia is associated with abnormal joint structure and a looseness of the muscles, connective tissue, and ligaments that would normally support the joint. As the joint becomes loose, the boney surfaces of the two bones lose contact and a separation or subluxation starts to occur. Over time there is a change in the size and shape of the bone, which can lead to arthritis. These changes cause discomfort in the hip and it is usually at this time that a dog is diagnosed with hip dysplasia. Diagnosis is made by x-rays and manual palpation of the hip.
Typical signs of hip dysplasia may include overall decreased activity, rear limb lameness, difficulty rising from lying or sitting position, reluctance to go up stairs, bunny-hopping gait, or reluctance to stand up on hind limbs. Hip dysplasia may or may not be bilateral. In severe cases, a full hip replacement can be performed by an orthopedic surgeon. Generally, however, treatment focuses on reducing discomfort and improving quality of mobility. Treatments may include the following: an anti-inflammatory remedy (natural, non-steroidal, or steroidal), joint protective products (glucosamine and chondroitin), physical rehabilitation (hydrotherapy, laser therapy, massage, and acupuncture), and specific exercises for the dog to do daily at home.
Many small breeds including Chihuahuas, mini and toy Poodles, Yorkshire Terriers, Pomeranians, and Jack Russells are born with unilateral or bilateral luxating patellas. This is caused by a very shallow groove on the femur bone in which the patella sits. When the knee is bent, the patella will slide out of place, moving either to the inside or the outside of the joint. In order for the patella to return to the correct location, the dog will straighten the leg for an instant. This is the typical “skipping gait” that is seen with this disorder. Genetic luxating patellas generally don’t cause discomfort, and therefore many dogs go undiagnosed as owners are unaware that there is an abnormality. Diagnosis is made by x-rays and manual palpation of the knee.
The amount of movement in the knee is graded between 1 and 4 (1 being the least). Lesser grades mean the patella will be in a normal position part of the time, and more severe grades result in the patella out of place most of the time. Often no treatment is necessary for a grade 1, but more severe cases may require surgical repair to prevent secondary arthritis, or muscle and ligament abnormalities in relation to the joint. Surgical repair has a high success rate.
A luxating patella can also be caused by a traumatic injury. In this case it is painful and requires a surgical repair right away so other joint structures won’t be adversely affected.
Cranial Cruciate Ligament Rupture
A common traumatic injury seen in dogs is the rupture of the cranial cruciate ligament in the knee. This injury is caused by a sharp twisting motion when stopping quickly or jumping down from a high spot. The ligament may be partially or completely torn. This injury causes an immediate limp, sometimes rendering the dog completely three-legged. Examination and diagnosis is crucial to ensure the best outcome for the patient as the ligament will not repair itself, and secondary arthritic changes usually occur. Diagnosis is made by manual palpation of the knee and x-rays.
Often a full tear of the ligament requires surgical repair by an orthopedic surgeon, with physical rehabilitation afterward. There are several different types of surgeries that have a high success rate. If surgery is not an option or the ligament is only partially torn, physical rehabilitation and a high-quality knee brace is beneficial to allow the dog to return to athletic endeavors. Partial tears of the ligament often become a full tear, or the other knee may become affected due to weight shifting onto this leg. For the best support of the knee, the following treatments are beneficial: anti-inflammatories, joint supportive products, physical rehabilitation, and specific home exercises.
Diagnosing these disorders early and starting treatment right away will improve the comfort and mobility of our canine friends, thereby greatly enhancing their quality of life.
Dr. Annette Richmond is a Certified Veterinary Acupuncturist and a Certified Physical Canine Rehabilitation Practitioner. Specializing in musculoskeletal disorders, she uses natural remedies and physical rehabilitation including hydrotherapy in an underwater treadmill, acupuncture, joint manipulation, therapeutic laser, massage, essential oils, and specific exercises to keep canines strong and feeling well. Dr. Richmond also offers casting and fitting for high-quality braces for the knee. Natural Veterinary Therapy is located at 510 Lighthouse Avenue, Pacific Grove. 831-655-0501.