Occasionally, we can see our dog limp for a few moments with his hind leg, and return to normal walking after a little while. Other times, this lameness persists for a long time, with variable intensity, and can limit our dog's mobility.
Whether it is the case of your dog, or if you have seen one in the park raising its hind leg after a few runs on the grass, we offer you from our site some of the possible answers to the question at hand: Why does your dog limp on one hind leg?
Anterior cruciate ligament rupture in dogs
The so-called "soccer player injury" also affects our dogs. It is one of the most typical pathologies in canine traumatology, which causes the dog to limp on one hind leg.
What is the anterior cruciate ligament?
This is a fibrous band that runs from the femur to the tibia, anchoring it so that it does not move forward or inward when the knee moves. There is another cruciate ligament that supports you in this mission, the internal cruciate ligament, but the most prone to breakage is the most external. These ligaments, together with the menisci and other structures, control the mobility of the knee and adjoining structures (femur, tibia, patella…).
Are there breeds predisposed to anterior cruciate ligament rupture?
We can consider, to facilitate information, that it mainly affects two different groups of dogs:
- Small-medium-sized dogs, especially middle-aged, short-legged dogs. It is inevitable to think of the shih tzu or the pug when mentioning this risk group. These breeds also have the drawback of being predisposed to discolagenosis problems, a degeneration of joint collagen that predisposes them even more to these problems.
- Large-giant dogs, such as the Labrador, Rottweiler or Neapolitan Mastiff.
However, any dog can suffer from a hind leg lameness due to anterior cruciate ligament rupture. Above all, dogs that do sudden exercise without warming up, in dry jumps to get on the sofa, or in a rotation while standing when turning to catch a simple ball.
And how to distinguish this limp from others?
Usually this hind leg lameness due to anterior cruciate ligament rupture appears suddenlyIt is very painful and the dog walks without supporting its paw, or does so very lightly. When he is standing, he extends the affected hind leg externally, that is, he moves it away from the body so as not to load the weight on it, and if he sits down, he usually extends the leg forward or outwards with respect to his body. They are ways to relieve stress on the knee.
Swelling may occur in the knee, but is not always seen. All symptoms will be more or less intense, depending on whether the ligament has been completely torn, or partially (like a frayed rope).
How is an anterior cruciate ligament rupture diagnosed?
The ways to diagnose it will depend on the case, but our veterinarian may need to sedate our dog to do the so-called " drawer test", in which an attempt is made to move the tibia forward while keeping the femur in place. If the ligament is torn, the shinbone will safely move too far forward, as there is no one to hold it in place. It is necessary to sedate the animal because the awake dog offers resistance as movement causes pain.
The X-ray does not confirm the rupture, but reveals signs of osteoarthritis that appear in the first weeks after the rupture of the cruciate ligament previous. The knee joint begins to degenerate, the joint surfaces become irregular and everything contributes to worsening the prognosis, hence the importance of going to the vet if you notice that your dog limps in one hind leg, even slightly.
In more complicated cases, and in well-equipped clinics, they can suggest an arthroscopy or an MRI.
Is there treatment for a torn anterior cruciate ligament?
There are two types of possible treatments:
- The conservative medical treatment, for cases in which surgery is not recommended. Rehabilitation measures with physiotherapy are proposed, which may include laser therapy or movements in water, together with products to reduce pain and protect the joint (knee protector) and, if the dog tolerates it, anti-inflammatories. In addition, a specific diet is established so that they do not gain weight and to favor the regeneration of joint cartilage or delay osteoarthritis as much as possible. They will indicate some rules for daily exercise and will emphasize the importance of nutrition, and how necessary it is to avoid slippery floors (if you have parquet or smooth floors at home you can use rubber boots), ramps down or walks downhill. In them, the knees suffer a lot.
- Surgical treatment: reconstructive surgery using various techniques requires a lot of dedication in the following days and constant monitoring of our dog to avoid movements abrupt. You can go home with a bandage that covers your entire hind leg or a dog knee immobilizer, and it will be up to us to keep you as rested as possible. They will recommend us to follow the same guidelines regarding food as in the case of conservative treatment (if they eat and do not move, they gain weight and that makes everything worse).
All the products mentioned to immobilize the affected areas and relieve pain can be found at Ortocanis It is necessary to point out that sometimes the other leg rear suffers the same fate after a few months. Let's suppose that our dog has been lame in the hind leg for a while, but it was not constant, and he could lead a normal life. We do not give more importance until it is evident, and we go to the vet. He diagnoses us and warns us that the other leg has been carrying the weight during these weeks, and will do so in the process of rehabilitation-recovery from surgery. So it's not unusual to see the other anterior cruciate ligament break, a kind of rebound effect.
Dislocated Patella in Dogs
The patella is housed between the trochleae of the femur, in a groove created especially for it. So to speak, it is like a wing chair: you can move up and down on it, but not left or right. If you look closely, the flexion or extension of the knee involves just that movement, up or down.
But sometimes the patella dislocates and starts to move laterally or medially. This can happen for two reasons, mainly:
- Congenital: since birth, the natural accommodation of the patella is defective, and it can move at will. It usually affects breeds such as toy poodles, Pekingese, Yorkshire…, and many times it is just one of the many congenital defects that these breeds can have at the bone level, such as legg calve perthes disease, for example. We will notice that our dog jumps, leaving the affected hind leg in the air when he goes down or up stairs, and then walks normally after a few steps. We usually think that it is because he is a puppy, but at that time it should be consulted, especially if he is one of the breeds that suffers most from patellar dislocation.
- Due to trauma: This dislocation can appear after a fracture, such as the one produced after a run over, or after a strong blow to the knee.
The degrees of dislocation are variable and can be solved by limiting exercise and other physiotherapy measures. Large breeds are not free from it, and lateral dislocation may appear in giant breeds, so our veterinarian will do a complete examination to rule it out.
What tests can be done?
Tests to detect patellar luxation and determine why the dog is limping on one hind leg are usually:
- Basic examination: the knee "crunches" upon manipulation.
- X-rays to detect signs of osteoarthritis, or breakage of the trochleae of the femur after a blow.
- Arthroscopy or MRI.
Although the veterinarian already has the diagnosis, it is necessary to know how affected the knee is, since the constant rubbing of the patella on the surfaces of the femur leads to wear and the development of osteoarthritis in dogs that is necessary to know to give a prognosis.
There are many surgical techniques that range from a relatively simple one, such as making the groove between the trochleae of the deepest femur, to others that are much more complicated ones that involve repositioning a piece of the anterior part of the tibia to relieve tension on the patella. Each technique will vary according to the case and according to the degree of dislocation (ranging from l to lV). Also how long it has been with this problem, or if there are more bone problems such as pathologies in the hips or the head of the femur.
Hip dysplasia in dogs
hip dysplasia is a pathology to which multiple causes contribute (management, environmental, food…), but it has a genetic basis. In summary, the head of the femur does not fit correctly in the specific hole for it in the pelvis, and although its triggering is multifactorial, the dog that the manifest has a "genetic programming" to suffer it. Hence, allocating dogs with this congenital pathology to reproduction is totally reprehensible.
There are breeds that are highly affected, such as the Labrador, Spanish Mastiff or Dogue de Bordeaux, for example. But there are various degrees of dysplasia, and mild ones may go unnoticed by owners at first. However, in moderate or severe cases, we will notice signs at 5-6 months of age. Our dog will walk with the hips "rocking" in a characteristic way, and over time, the head of the femur will rub against the acetabulum in which it does not quite fit, and cause arthritis and osteoarthritis. Hence the often acute limp, which can be seen in one or both hind legsIf the ligament that joins the head of the femur to the acetabulum is completely torn, the condition is usually even more serious.
Symptoms of hip dysplasia
The symptoms, in addition to the typical rocking gait that we detect at the beginning, can be:
- Difficulty starting to walk after a period of rest.
- Muscular stiffness.
- Resistance to movement, especially going down and up stairs.
- Finally, when the degenerative changes of the hip joint are severe, acute lameness that makes walking impossible.
What is hip dysplasia treatment?
Treatment is complicated, and you can try rehabilitation with physiotherapy in milder degrees, also providing a quality diet designed for joint and bone pathologies, paying special attention not to provide excess calcium, a mistake that was made with fast-growing giant breeds. Anti-inflammatories and cartilage protectors such as hyaluronic acid and chondroitin sulfate are indicated to help stop progression and improve long-term symptoms.
In more severe degrees, dysplasia must be corrected by orthopedic surgery, usually complicated. There are multiple techniques, from the excision of the head of the femur (arthroplasty) if the dog is small or medium and does not have to bear much weight, to the triple pelvic osteotomy, an aggressive intervention that is sometimes the only solution for our dog to return to walk. The titanium prostheses to replace the head of the femur have been used for some years with great success, but their cost is high and they are reserved for cases that do not they are expected to respond to no further surgery.
One way to improve the dog's quality of life, avoiding side effects caused by anti-inflammatories, is through Ortocanis aids, ideal for these cases. For a dog with mild to moderate hip dysplasia, the hip support is used, which offers slight pressure on the muscle group and warms the joint, reduces pain and improves performance, which will prevent muscle atrophy and the consequent increase in joint instability. If the dog needs help to walk, we can use the rear support harness or the aid band. For more serious cases, it may be necessary to resort to the wheelchair, which restores mobility to the animal and allows it to have the necessary physical activity to maintain its state of general he alth.
In our article on hip dysplasia in dogs you can find more information about this possible cause of hind leg lameness.
Growth panosteitis in dogs
The term panosteitis refers to "inflammation of the entire bone or all the bones", literally. The pain in this case is due to a inflammation of the outermost layer that covers the bone (periosteum), and although it may be due to several causes, the one that concerns us here, it is growth panosteitis.
It is much more frequent in fast growing and marked dogs, that is, large and giant breeds in the months of development (between 5-14 months of age, in general). They usually affect long bones, such as the femur, which is why they can cause lameness in the hind leg.
Sometimes it occurs acutely, and other times more mildly. The use of anti-inflammatories, a careful diet, a pattern of gentle exercises and, above all, time, makes it disappear.
Avascular necrosis of the femoral head
Legg-Calvé-Perthes disease or avascular necrosis of the femoral head is another cause of hind leg lameness in dogs. It usually affects growing mini or toy breeds, such as the mini pinscher, toy poodle or Yorkshire, and is sometimes confused with hip dysplasia.
Symptoms of avascular necrosis of the femoral head
The head of the femur stops receiving blood flow at a critical stage (which is why it becomes necrotic), and between 4-9 months we can see the following symptoms:
- Mark lameness.
- Muscle atrophy.
- Shortening of the affected leg (due to muscular atrophy).
- Crepitations on handling and manifest pain.
Is it hereditary?
Until a while ago it was accepted that it was the only explanation. But now it is believed that microfractures in the area produce a drastic reduction in blood supply and, hence, death or necrosis of the femoral neck and head. Surely the small size of the affected breeds predisposes them to suffer those small continuous traumas in the area, which ends up leading to this disease.
Its treatment is surgical, by excision of the affected femoral head (it can be both), and the fact that dogs affected tend to have a very small size, facilitating surgery and recovery.
More information is available on Legg-Calvé-Perthes disease in the article on our site entirely dedicated to it, check it out!
Other causes of hind leg lameness in dogs
There are dozens of possible causes that can cause our dog to limp in the rear leg, in addition to those mentioned. If you still haven't found an answer to the question "why does your dog limp on the back leg?", it may be in this list that we present to you below:
- Osteosarcoma: is the most common primary bone tumor in dogs and one of the most malignant. It generally affects medium-large breed and young dogs more, although it can be seen in any size and age. In the hind leg, its most typical location is near the knee, in the distal part of the femur or proximal part of the tibia. It is very painful, rapidly progressing and invasive. Once diagnosed by means of plates and histopathology, the amputation of the extremity is obligatory, and the dog will need chemotherapy, since it metastasizes very easily. Affected dogs have a few months of survival, but it can be extended with an appropriate chemotherapy protocol.
- Fractures in metatarsals and phalanges: the fingers and phalanges are prone to "accidents", especially in puppies that play wild. Sometimes it is a simple fissure, and on other occasions a fracture that needs the use of splints to be reduced. In metatarsal or phalangeal fractures, surgery tends to be avoided, using containment means such as splints or bandages, in addition to anti-inflammatories and rest.
- Footpad Injuries: It is clear that an injury to the footpads can cause lameness, such as a cut, abrasions, irritations…, therefore, thoroughly reviewing them is usually the first step that our veterinarian will take in the examination when our dog comes to consultation with a lameness in the rear leg.
