Reprinted with permission from Purina Pro Club Resource Library (June 2013).
Active sporting dogs, even well-conditioned ones, are at risk for orthopedic problems. Here is a review of the most common orthopedic problem seen by veterinarians, cranial cruciate ligament disorders, and the most common cause of front leg lameness, elbow dysplasia.
A Developmental Disorder
When a sporting dog starts limping in a hind leg, it may be due to a problem with the cranial cruciate ligament (CCL). One of the main supportive structures of the stifle (knee) joint in a dog’s hind limbs, the CCL plays a key role in stabilizing the femur (thighbone) to the tibia (shinbone).
Comparable to the anterior cruciate ligament (ACL) in humans, the CCL functions like a rope, preventing the stifle bones from shifting during activity. Without the normal CCL stabilization, a dog’s movement is compromised and painful osteoarthritis develops. Reluctance to bear weight on the leg, decreased performance and/or signs of pain in the stifle are often the first things an owner notices in a dog with a CCL problem. Swelling of the joint, clicking when walking, stiffness after exercise, sitting with the leg extended to the side, and holding the leg up also are common.
“While these signs may be noticed acutely after an incident or injury, they almost always are the result of a slow breakdown of the CCL and thus some degree of arthritis is invariably already present in the joint,” explains James L. Cook, D.V.M., Ph.D., DACVS, DACVSMR, director of the Comparative Orthopedic Laboratory at the University of Missouri College of Veterinary Medicine. “Owners who recognize these signs should take their dog to the veterinarian for a complete diagnostic evaluation.
“In the vast majority of dogs, CCL tearing occurs as a developmental disorder, rather than a single injury, and is related to the structure of a dog’s stifle joint as well as degenerative changes noted in the CCL during aging. For these reasons, we prefer to refer to this condition as CCL disease rather than a CCL tear or CCL rupture. Unfortunately, at least 60 percent of dogs that develop CCL disease in one hind leg will develop the same problem in their other hind leg within two years.”
The high prevalence of bilateral (both stifles) CCL disease in dogs led Cook and his research team to study methods for early diagnosis of CCL disease in dogs that are not yet lame, as well as novel treatment options designed to improve the safety and efficacy of therapeutic interventions. They are completing a clinical trial using a biomarker panel they developed and patented that shows promise for determining which dogs are likely to have CCL disease in the future.
“Using just a few drops of joint fluid from the stifle, we can measure the levels of seven proteins that can indicate the presence of CCL disease prior to clinical signs,” Cook explains.
Currently, to diagnose CCL disease, a veterinarian evaluates the way a dog sits and walks, and palpates the stifle joint for instability, known as a cranial drawer test. Radiographs are performed to help verify the diagnosis, assess the severity of arthritis, determine treatment options, and make sure there are no other problems.
Though there is no cure for CCL disease, treatment can help relieve pain, improve function and slow the progression of osteoarthritis. Nonsurgical treatment involving rest, pain-relieving medications and physical rehabilitation can be effective for some dogs. However, surgery to stabilize the stifle results in more consistent functional outcomes, particularly in performance dogs.
Surgical stabilization procedures include TightRope (TR) CCL, lateral suture (LS), tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA). TR and LS are extracapsular stabilization procedures in which a synthetic material is placed attaching the femur to the tibia to mimic the function of the CCL and allow fibrous tissue to form for long-term stability. TPLO and TTA are osteotomy (bone-cutting) procedures designed to alter the anatomy of the stifle so stability is achieved through reorientation of muscle forces.
Each procedure has advantages and disadvantages, and an owner should carefully research the options before choosing which one is best for his dog. Costs range widely, from $600 to $6,000, based on the procedure and type of veterinary practice and location. The choice of treatment should be individualized to the dog and made after a thorough discussion with the surgeon.
The recovery and return to a sport after treatment of CCL disease is a long-term process. “It typically takes six months before a dog is ready to safely resume field trials or other intense activities,” Cook says. “A dog should be carefully restricted after surgery until healing is complete, typically at least eight weeks. Then, post-surgical physical rehabilitation and long-term strength and flexibility training are key to a dog’s success in regaining full function and performance.”
Elbow Dysplasia: A Group of Disorders
Elbow dysplasia, which describes a group of disorders, is a common cause of lameness in a dog’s front legs. Large breeds, particularly working and performance dogs, are susceptible to elbow dysplasia. It is an inherited condition that begins when puppies enter their rapid growth stage between 4 and 10 months of age.
The disorder is caused by abnormal formation of one or more of the three bones that make up the elbow joint, causing cartilage and bone on the joint surfaces to develop improperly. This leads to fragmentation, detachment, fissuring, and/or wearing away of the cartilage and bone. Eventually, this culminates in osteoarthritis and bone-on-bone grinding in the elbow.
Early detection during puppyhood provides the best chance for successful treatment, though this can be difficult as the signs often are not apparent until a dog is older. Orthopedic examinations performed by specialists and radiographic screening through the Orthopedic Foundation for Animals are considered the best methods for early diagnosis.
“Elbow dysplasia is caused, in part, by genetics but can be exacerbated by athletic activities,” Cook explains.
Pain in the left elbow became unbearable for a male German Shorthaired Pointer, Cadens Cowboy Tex Vanrostig, particularly after hunting with his owner Richard Krings of Pewaukee, Wis. After a day working, “Tex” would hold up his front leg in pain.
Krings made several trips to the emergency veterinary clinic over three years, trying to learn the cause of his dog’s pain. When he took Tex to the University of Wisconsin Veterinary Medical Teaching Hospital, an orthopedic examination, radiographs and computed tomography (CT) scans showed the problem. Large bone chips could be seen inside and outside the elbow joint, and they had worn away all the cartilage on the medial (inside) part of the joint.
Tex was diagnosed with FMCP (fragmented medial coronoid process) and severe medial compartment arthritis. The slow, deteriorating condition had caused so much pain that Tex could no longer hunt. Tex had an initial arthroscopic surgery to remove the bone fragments to try to halt the damage to the joint. The procedure improved Tex’s condition, but he continued to limp.
Krings researched the condition and learned about a new treatment, a canine unicompartmental elblow (CUE) joint resurfacing procedure performed by Cook at the University of Missouri. The procedure, patented by Arthrex Vet Systems in Naples, Fla., involves resurfacing the medial part of the elbow joint with a metal and plastic implant.
Krings offered to bring Cook to the University of Wisconsin to perform the CUE surgery, where he would teach the procedure to veterinary surgeons and residents eager to learn about this less-invasive, bone-sparing option. The CUE implant was becoming known for its success in resurfacing the bone-on-bone medial (inside) compartment of the elbow joint while preserving a dog’s good cartilage in the lateral (outside) compartment. The technique was developed to treat dogs with medial compartment disease, the end stage of elbow dysplasia.
Tex’s surgery was successful. After a day in the hospital, he went home with antibiotics, pain medications and a bandage on his leg that he wore for two weeks. He had to be calm for two months following the surgery, with controlled leash walks and no running. After a follow-up examination at 10 weeks, he began rehabilitation to return to hunting.
Owners of dogs with elbow dysplasia report noticing changes in the dog’s gait and decreased performance and endurance in the field. Limping on a front leg or swinging the front leg(s) while walking is common.
A veterinary orthopedic specialist examines a dog to determine elbow dysplasia by looking for joint thickening and swelling, pain when the joint is manipulated and loss of range of motion. Radiographs confirm the presence and type of elbow dysplasia and the severity of arthritis. Advanced imaging, such as CT scans, magnetic resonance imaging or arthroscopy of the joint can help determine the extent of the problem.
The three most common types of elbow dysplasia, each involving different areas of the elbow of affected dogs, are:
- FMCP is the most common type and the most difficult to see on a radiograph. Advanced imaging is often needed to detect this disorder. The bone and cartilage on the medial (inside) portion of the elbow joint develop cracks that cause fragmentations of bone and cartilage, leading to secondary osteoarthritis.
- Osteochondritis dissecans (OCD) — Rapid growth of body size and weight contribute to this condition in which cracks in the cartilage affect the soft bone beneath it and cause the joint cartilage to separate and form a flap that irritates the joint and results in inflammation and damage.
- Ununited anconeal process (UAP) — This is a condition in which a bony protuberance within the elbow becomes detached from the ulna bone, damaging the inside of the elbow joint. In normal dogs, this protuberance fuses with the end of the ulna by 5 months of age.
Treatment depends on the type and severity, as well as a dog’s age and intended function. Weight-control programs, exercise modification and analgesics or anti-inflammatory agents, such as tramadol, carprofen or deracoxib, are nonsurgical therapies that benefit some dogs. Arthroscopic surgery, such as Tex initially had, can help by removing fragments and abnormal cartridge and bone in the joint, typically benefitting younger dogs. When these treatments don’t alleviate the problem, a CUE procedure provides an option.
Though CCL injuries and elbow dysplasia sometimes cannot be avoided, it is important to seek veterinary care as quickly as possible so that a definitive diagnosis can be made and treatment options can be considered. Though it took three years before Tex was properly diagnosed with FMCP, Krings credits the CUE procedure with Tex’s ability to regain a normal life.
Raising Awareness About Shoulder Instability & Foot Injuries
Shoulder instability and foot injuries are fairly common in canine athletes. Owners who look for signs of problems by checking their dogs over after a day in the field will help prevent pain and aid recovery.
“Dogs that run hard uphill and downhill are particularly prone to shoulder instability,” says Robert Gillette, D.V.M., DACVSMR, director of Veterinary Sports Medicine & Rehabilitation at the Veterinary Specialty Center in Buffalo Grove, Ill. “These injuries typically are the end result of a traumatic event and usually are seen in a dog’s lead shoulder. A dog may exhibit forelimb lameness or collapse at the end of a jump.”
Shoulder instability may start with subtle signs, such as a “head bob” when walking or trotting, decreased endurance or level of performance, or refusing to do certain activities such as jumping or working in heavy cover. Veterinarians diagnose the condition by conducting a complete orthopedic examination, which includes ruling out other problems, such as elbow dysplasia and elbow and foot injuries that can cause similar signs. Ultrasounds, magnetic resonance imaging and/or arthroscopy may help diagnose the problem.
Depending on the type and severity, the veterinarian may first recommend nonsurgical treatment consisting of activity restriction and then physical rehabilitation over three or four months aimed at building shoulder muscle strength to improve stability.
More severely affected cases may need surgery. An arthroscopic TightRope procedure, similar to the one used to treat CCL disease, can be used to address shoulder instability. This minimally invasive procedure has proved successful in returning performance dogs to full function.
Among common foot injuries are fractures, ligament strain, synovitis, tendon inflammation, lacerations, bruises, and puncture wounds. “Dogs’ feet can withstand a lot of wear and tear because of the keratin epithelium that covers the pads,” Gillette says. “The thick layer of skin provides protection for the foot’s tendons and ligaments, acts as a shock absorber and provides traction. However, the pads are not impenetrable.”
To help avoid foot injuries, owners should keep their dogs’ nails short. A longer nail gets caught on things and can also act as a fulcrum on the paw’s bones and ligaments, which can result in toe fractures, dislocations and nail injuries.
It also is important to clean the dog’s paws and pads following a day in the field. Cleaning can help prevent infections and allows owners to spot a laceration or puncture wound before it becomes a bigger problem. A good examination of the pads includes digital pressure applied to the bottom and sides of each pad, inspecting the webbing and closely observing the surface of the pads. You also should check nails for discoloration and swelling or redness where the nail goes into the toe, signs of infection.