The causes of hind leg lameness in dogs can be several. Causes may involve problems of the nails, joints, muscle, bones, blood supply to the leg, or neurologic disease. Treatments for each of these issues can be vastly different. Because of this, veterinarians need to gather as much information as possible to make an accurate diagnosis and individualized treatment plan. In this article veterinarian Dr. Eric Weiner will discuss a basic work up and some of the more common causes of hind leg lameness in dogs.
At the Vet's Office
A good physical exam starts with a thorough history. The veterinarian will be listening for clues to help determine what the most likely cause of the issue may be. These include age, breed, and weight of the dog. Some issues are more likely in certain age groups, size of dog, and/or breed and activity level.
What has the progression of clinical signs been? Has the limping been getting worse over time, or did this happen suddenly? Is the dog on any current medications, and if so, how has it responded to them? This information helps point the doctor in a general direction what which body system (orthopedic, neurologic, etc.) to pursue.
While talking to the owner, the doctor will be observing the pet to determine its mentation, pain level, and mobility. Then they may have the pet do a few laps in the hallway to observe it walk.
Lameness is typically graded on a scale from one to four. One is a slight limp, and four is completely non-weight bearing, or holding the leg completely up. I will then go through a complete physical exam, leaving the ouchy part for last. Are there any other body systems affected? Once I am ready to evaluate the leg, I will typically look at the nails and paw pads to rule out the east stuff first—broken nails, cuts, foreign material, etc. Then I will work my way up pressing on the bones and go through range of motion, flexing and extending each joint individually.
This process helps localize the problem. At this point recommendations can be made regarding need for further evaluation and/or best treatment approach. Remember that there are different approaches to the same problem and depending on the veterinarian’s preferences, different steps may be taken. Here is a list of some of the more common causes of hind leg lameness in dogs that we generally see.
Causes of Hind Leg Lameness in Dogs
Broken nails can be seen on any breed at any age. Sometimes having longer or overgrown nails may predispose pets to getting their nails snagged on things and break. Often owners may see limping, some bleeding and a nail pointing in an abnormal position. The treatment is to pull the broken nail off like a bandaid. But please allow the veterinarian to make the assessment. Some nails are not ready to be pulled and that action can cause more pain and harm.
These pets will often go home with some anti-inflammatories for discomfort. The nail will grow back, as long as there is no damage to the nail bed, but may grow back in a weird direction. The lesion will typically be cleaned with an antiseptic solution, but oral antibiotics are not always needed. Keeping the nails short may help prevent this.
Paw pad lacerations is one of the most common issues working and agility dogs experience. Clinical signs include limping, bleeding, and sometimes excessive licking at the paw. Treatment depends on location and severity of the cut. Cuts on the feet may take longer to heal than other parts because it is a weight bearing surface. Each time the pet walks, it puts pressure on the area and delays healing.
If stitches are necessary, they would be placed under anesthesia or heavy sedation. A bandage will likely be placed to keep the wound clean. Pain meds and anti-inflammatories are commonly used, but antibiotics may not be needed in these cases either. The determination for antibiotics is based on severity, age of lesion, how dirty it was, and how damaged the tissues were. An Elizabethan collar (the “cone of shame”) will likely be recommended to prevent the pet from chewing and the foot, which could introduce bacteria, cause infection and delay healing.
Foreign material may also be found between the foot pads and cause problems. Most common offenders include plant material (grass awns, spurs, etc.), glass, and bee stingers. Careful removal of the object and diligent cleaning with antiseptic solutions are keys of treatment.
Anti-inflammatories, antihistamines, and antibiotics may be sent home depending on the case. Prevention involves removal of those offending agents from the environment when possible. Dog booties can be placed on their feet if removal of potential agents is not feasible.
Broken bones. Dogs can suffer from broken bones too. Most often it is due to trauma, such as being hit by a car, falling out of a window, animal abuse, or any other form of physical injury. Occasionally, dogs may suffer from pathological fractures. This is a bone fracture that occurs after a benign force, something that should not have resulted in a broken bone.
Bones that succumb to pathological fractures have some preexisting condition that weakens the structural integrity, making them more brittle. Bone cancer and hypocalcemia (low levels of calcium) are two examples of diseases that may lead to these types of fractures.
Broken bones are classified by several factors. If the skin in the area is intact, the fracture is considered closed. Alternatively if there is a puncture wound in the same area, whether a bone segment is sticking out or not, it is considered open. Open wounds are usually more serious and more likely to become infected. Nondisplaced fractures are those where the bone segments are still properly aligned. Displaced fractures have segments that are no longer in contact with each other.
The number of segments (simple vs comminuted) is also important to classifying fractures and formulating the best treatment plan. Lastly, fractures that involve a joint typically carry a worse prognosis for return to normal function and require more aggressive treatment.
Clinically these dogs present either toe touching or completely non-weight bearing lame with a sudden onset. A history of trauma may or may not be known. The patient is typically very painful and may guard the area to protect it from further pain. There may be other evidence of trauma such as road rash or lacerations depending on the cause.
The physical exam may reveal pain, decreased range of motion and instability of the bone and/or joint. X-rays are then taken to confirm and assess the extent of the damage. Sedation is often recommended as proper positioning can be painful and we obviously want to control pain as much as possible. Multiple views of x-rays should always be taken to evaluate the area in multiple planes because they are 2D images of a 3D structure. Single views lead to lack of information and misinterpretation. Sometimes advanced imaging such as CT scans can be beneficial, especially for surgical planning. CT scans are most often performed at referral centers and require general anesthesia.
The recommended treatment approach depends on the age of pet, extent of injury or injuries, location and classification of the fracture. Dogs that may be good candidates for casting or splinting are young dogs with closed, nondisplaced fractures without joint involvement. The negatives of casting include the potential for a malunion or incomplete repair, need for frequent bandage changes and visits to the vet, and complications from the bandage itself, such as pressure sores, swelling, skin infections, etc.
There are many different types of surgical corrections as well. Both internal and external fixation techniques may be available, which are determined by the surgeon on a case by case basis. These typically yield a more complete and quicker repair. Disadvantages of surgical correction include anesthetic risk, more invasive in nature, and potential for implant (plate, screws, etc.) infection and failure. Of course, care is taken to minimize the complication rates as much as possible. Surgical repair may be more expensive initially, but the price disparity compared to casting after frequent bandage changes and vet visits are factored in may not be as drastic as expected.
Regardless of treatment approach, other mainstays of management include activity restriction, anti-inflammatories, pain medications, and potentially antibiotics depending on the situation.
Luxating patellas are very commonly seen in mostly small breed dogs. This is a disease of the knee, which can be either unilateral (one side) or bilateral (both knees affected). The knee cap, or patella, of a normal dog glides up and down within a groove as the dog bends its leg. The kneecap of a dog with luxating patella actually pops out of the groove, preventing normal joint movement.
There is a grading system of one to four. Those characterized as a one can have their kneecap popped out of the groove, but then it goes right back in. A four would be a dog whose groove is so shallow that the kneecap is always out. The most common clinical sign is a dog that will suddenly hold a back leg up and hop for a few steps, then walk normally as if it never happened. What happened is that the kneecap popped out, then back in on its own. The more often this occurs, or the longer it takes for the knee cap to go back into place (if it does at all), the more significant the problem is.
Patellar luxation is considered a surgical problem, but surgery is usually reserved for the bad three’s and four’s out of four’s on the grading scheme. This disease can progressively get worse, but does not always. Preventative or management measures that can be taken include keeping your pet at a healthy weight and adding joint supplements. The heavier the pet is, the more load those joints carry, which promotes faster degeneration. Supplements such as glucosamine chondroitin and omega 3’s help with joint lubrication and nutrition.
Cranial cruciate ligament (CCL) disease is the most common orthopedic disease in small animal medicine. The human equivalent is an anterior cruciate ligament (ACL) injury. One difference is in humans, it is commonly caused by a sudden injury (the quarterback getting tackled) versus in dogs it can happen more gradually with little tears over time.
The CCL is attached from the back of the femur to to front of the tibia and prevents the tibia from sliding forward. Large breed dogs are predisposed to developing CCL injury as are overweight dogs and highly active dogs. Injury to a cushioning cartilage called the meniscus can cause a sudden onset of clinical signs and can complicate the treatment.
Clinical signs include a hindlimb lameness that can be ranked one to four, but most often at least a three. These dogs are painful and may become lethargic and have a decreased appetite. The onset can be sudden or gradual. A physical exam may reveal swelling around the knee and medial buttress, which feels like a firm bump on the medial (inside) aspect of the knee. This is excess fibrous tissue the body produces in attempt to stabilize the joint.
These dogs also have what is called cranial drawer movement. This is when the leg can be manipulated to move the tibia slightly forward independent of the femur. Sedation is sometimes needed as false negatives can occur if the awake dog tenses all of its leg muscles, even with complete tears. A cranial tibial thrust may also be performed which is when the doctor pushes up on the ankle (tarsus), which then forces the top of the tibia to move forward in the affected patient. X-rays show soft tissue swelling within and around the knee and may show misalignment of the top of the tibia in relation to the end of the femur.
CCL injuries can be treated both medically and surgically, but surgical intervention typically yields a quicker and more complete return to normal function. Medical management includes anti-inflammatories, pain medications, and strict activity restriction for at least six to eight weeks.
There are many different surgical techniques to repair CCL injuries. An extracapsular lateral suture repair basically uses a sterile fishing line to replace the function of the injured ligament. This procedure has more success in small breed dogs and can be performed without special equipment within a general practice setting. Other techniques such as a Tibial Plateau Leveling Osteotomy (TPLO) and the Tibial Tuberosity Advancement (TTA) involve cutting bone and adjusting the biomechanical angles and forces of the joint. These techniques have been shown to be more effective than the extracapsular repair, however are more often performed by specialists and may be more expensive. The chosen technique is often determined by case specifics, tools available, and surgeon preference.
Unfortunately dogs that suffer from cruciate disease on one side often develop cruciate disease on the other leg. There are no proven preventatives that can be given to avoid this. However keeping the dog at a healthy weight, joint supplements, and controlled exercise may help delay onset of disease. There is a lot of information out there to reference for more detail about this disease and treatment.
Hip dysplasia. There are many other diseases of canine hind limbs, however the last one discussed in this article will be hip dysplasia. Hip dysplasia is a hereditary disease in which the socket part of the ball-and-socket joint does not adequately cover the ball. In the analogy, the socket is the acetabulum located on the pelvis, in which the femoral head, or ball, fits in. When there is not appropriate coverage, limited range of motion, pain and arthritis develop. This disease is passed on genetically, which makes screening commonly affected breeds before breeding so important. The breeds that are most commonly affected include Golden Retrievers, Labrador Retrievers, German Shepherd Dogs, and other large breed dogs.
Orthopedic Foundation for Animals (OFA) and PennHIP are two accepted screening methods used and strongly recommended prior to breeding commonly affected dogs. The OFA method provides qualitative [somewhat subjective] analysis on standard pelvis X-rays, whereas, the PennHIP technique provides a more objective quantitative analysis. Each method have their benefits and drawbacks.
The OFA technique can be performed by any veterinarian and does not necessarily require anesthesia, but the patient needs to be at least two years of age. The PennHIP technique can only be performed by veterinarians with the specific certification, requires anesthesia, but can be done as early as 16 weeks of age. Screening dogs that will not be used for breeding is not necessary.
Clinical signs depend on severity and chronicity of the disease. Owners may notice difficulty getting up, decreased activity, and bunny-hopping. A physical exam may reveal findings consistent with arthritis, decreased range of motion, laxity or looseness of the hip joint, pain on manipulation, and thigh muscle wasting. X-rays can confirm poor acetabular coverage, signs of arthritis and decreased leg muscle mass.
Medical management is attempted prior to recommending surgery. Mainstays of medical management include weight control, anti-inflammatories, pain meds, joint supplements, as well as physical therapy. Swimming is a great low impact exercise that is great on joints. Alternative therapies that have been shown to benefit dogs with arthritis include laser therapy and acupuncture. Surgeries may involve cutting bone and repositioning to promote better hip congruity, or salvage procedures such as total hip replacements. Determining factors include age and size of pet, severity of disease, activity level/job and surgeon preference. The best prevention is not breeding affected dogs.
There are many more causes of hindlimb lameness in dogs. The goal of this article was to discuss some of the most common causes and the systematic step-by-step approach veterinarians use to localize, diagnose and treat these issues.
About the Author
Dr. Eric Weiner is a small animal veterinarian practicing in Orlando, Florida. He is a third generation veterinarian as both his father and grandfather are vets. Although he grew up following both of them around and wanted to be a veterinarian himself, he took a bit of a detour and attended Hofstra University originally as a music major.
Eventually realizing his true passion still lays within Veterinary Medicine, he switch majors and graduated in 2010 with a BA in biology and dual minors in biochemistry and music. Dr. Weiner attended Virginia-Maryland Regional College of Veterinary Medicine and graduated in 2015, concentrating in mixed animal medicine and surgery.
During his clinical year, his favorite rotation was which ever he was currently on. He especially enjoyed spending time at the Penn Vet Working Dog Center, where he worked closely with search and rescue dogs, diabetic alert dogs, and even cancer detection dogs.
When Dr. Weiner is not working with animals, he enjoys riding his motorcycle and playing baseball. He is married to his high school sweetheart and they are enjoying their brand new baby girl. In addition, they live with their therapy dog Murphy, and two cats, Stella and Luna.