You may notice your dog kicking their back feet. This can be normal behavior, but in some cases it can be a sign of something serious. Here are some of the most common instances where you will observe your dog kicking their hind legs:

If your dog is eating, drinking and behaving normally, they are most likely not in any serious danger but should still be checked by your veterinarian. Although it will not be immediate, some causes of muscle spasms and kicking in the back legs can cause long term damage to your dog if not treated.

Your dog’s kicking can be a behavioral issue or an illness. If they are simply marking their territory, it will not be a danger to their health. However, other causes can be dangerous and your pet should be checked by the vet as a precaution.

It is not unusual to see your dog kicking their back legs against the ground and kicking up dirt after they go to the washroom. Some people assume that they are trying to cover up their feces or urine, similar to how a cat would. This is in fact not true. The real reason to why dogs do this is to mark their territory. Canines have scent glands in the back of their feet, and when they kick against the ground they are trying to leave behind their scent. Dogs who are dominant will do this with the goal to warn others dogs to stay away unless they want trouble. Pets who are more submissive will do this to let others know that they were there but that they aren’t a threat.

Dogs that have uncontrollable rhythmic spasms can be experiencing petit mal seizures. This illness will affect small groups of muscles in one particular area. More serious than petit mal seizures are grand mal seizures, in which your dog will experience complete loss of consciousness, uncontrollable contractions of muscles in the whole body and possible loss of stool and urine continence. Grand mal seizures have a higher chance of causing an increase in the body temperature and consequently, brain damage. Infections, arthritis, nerve inflammation and damage, as well as disturbances in minerals and electrolytes, can also be causes of muscle spasms. They can be caused by overexertion, physical injury or neurological damage. Dogs who take part in high levels of physical activity or don’t have a proper intake of fluids can experience muscle spasms due to interruptions in their muscle contractions. They are easy to identify and will appear as tremors or twitching in a particular part of your pet's body. They will often react to touch as well. Since, in most cases, muscle spasms are a result of another medical condition or injury, you may notice other symptoms aside from the spasms. Lameness, signs of pain and depression are often observed.

Some dogs with very active REM cycles can experience leg jerks and muscle spasms during their rest. These will only happen when your dog is sleeping and often occur in younger and older dogs, as their sleep cycles are different compared to young adult pets. If your dog cannot be awakened, they could possibly be experiencing seizures during their sleep which is causing your dog to kick their legs and perform other random movements. Once awakened from a seizure, they will most likely show confusion and coordination problems. If your pet can be awakened, it is not a seizure.

Degenerative joint disease, or DJD, occurs when there is a loss of smooth cartilage that is protecting and covering the end of bones in movable joints. This cartilage has no nerves and therefore, when bones touch and move against each other, there is no pain. When that cartilage disappears, however, the dog will experience pain as the bones, which do have nerves, will be rubbing directly against each other. There will also be inflammation and other signs of arthritis. This is a progressive disease, meaning that it will get worse over time. DJD can occur due to wear and tear on a joint, as well as aging. It can also happen as a result of other diseases, such as dysplasia. 

Dogs with congenital joint problems or those who have previously experienced an injury to a joint are more likely to develop degenerative joint disease. Signs can vary depending on your dog’s age, the disease’s severity as well as which joint is involved. The first noticeable sign will be an altered gait, followed by a reduction in the size of the dog’s muscle, and the possibility of a change in appetite and behavior, depending on the level of pain that your dog is experiencing. There can be stiffness in the limbs, lameness and reluctance to perform some movements, weight gain and increased sleeping. Some dogs will also lick and bite at the affected area.

This is when the kneecap moves in and out of place. It is a somewhat common orthopedic condition seen in dogs.. Medial patellar luxation can happen to any dog, but is often found to happen to small dogs, especially Pomeranians, Chihuahuas, Miniature Poodles and Boston and Yorkshire Terriers. Larger dogs that are predisposed are Flat-coated Retrievers, Chinese Shar-Pei, Great Pyrenees and Akitas. In some cases, it will affect both back knees of the dog, and in other cases only one knee will be affected. This disease can be the result of an injury to the knee, or could simply happen to dogs who have shallow femoral grooves. It can also be a consequence of an abnormal conformation or malformation of the hip joint, the tibia or the femur, deviation of the femur crest or tightness of muscles. 

Signs will vary depending on how severe the disease is. Dogs who are affected will often skip or hold up their limb for a few steps and shake or extend the leg out. As the disease gets more serious, the lameness may become more frequent. Puppies with this disease can often have a bowlegged appearance that will get worse as they age. Over time as the knee comes out of place more frequently, it can erode the cartilage and expose the bone, which can lead to arthritis and pain.

Although a dog kicking backwards to mark their territory may not be a health issue, you can help your veterinarian determine the cause of muscle spasms by reporting your observations, like when and where it occurs, what your dog was doing before it happened, medical history and their usual levels of activity as well as any current medications or recent injuries. If petit mal seizures do not seem to bother the dog, they may not have to be treated as they may not be a  serious health concern. That being said, you should still seek advice from your veterinarian as it could be a sign of an underlying issue that could potentially be more dangerous, for example a slipped disc, pinched nerve or damage to a muscle. Muscle spasms related to arthritis can be treated with pain medication that your veterinarian can recommend for your dog.  If serious, your pet may require massages and other forms of physical therapy, and in some cases surgery to remove the affected nerves. If the problem occurs while your pet is asleep, it can be helpful to record any observations or information of the event to relay to your veterinarian, as your pet will most likely not sleep at the veterinarians office. 

Physical exams and a history of the dog’s signs will be necessary to diagnose degenerative joint disease. X-rays or other tests may be needed. Since it is a progressive disease, treatments can be medical (to slow down the process) or surgical (to replace the joint). Fixing patellar luxations may require your dog to be sedated in order to properly assess the damage. The veterinarian may evaluate for hip dysplasia as well as take x-rays of the tibia, pelvis and knee to see the shape of the bones. Blood and urine tests will take place before anesthesia as a precaution. If the patellar luxation does not produce any signs for the dog, it may not require correction by surgery. If it does produce signs, your pet may require medication, or surgery, depending on the severity of the problem.  

The simplest way to avoid muscle spasms related to over-exercise is to keep your dog hydrated and not overworked. Help them warm up and cool down before and after periods of intense exercise. Arthritis and degenerative joint disease can be hard to prevent but can be delayed if caught early and treated with medication and treatment recommended by your veterinarian. Keep your dog in shape, but keep them from jumping from high places or other activities that could potentially cause injury.

When you notice your dog experiencing muscle spasms, offer them plenty of water and try to massage the area gently. Heat and cold therapies can often help with discomfort. To keep them from recurring, try giving your pet a supportive diet and strengthen their muscular systems without overworking them. For dogs who have trouble sleeping and experience problems with their REM cycle, there are several things that you as the owner can do to eliminate or make the problem easier. For example, adding a nightlight, checking your house for any nocturnal creatures that may be living in the walls and keeping your pet awake, add white noise for dogs who have trouble falling asleep due to noises, ensure that it is not too hot or cold, evaluate for any potential causes or anxiety or stress in your dog’s life and, most importantly, contact your vet. To help your dog be comfortable when dealing with problems related to arthritis, find them a soft place to sleep, such as memory foam or heated beds. Dog stairs and ramps can also help dogs who have difficulty getting around.

Depending on the cause, stopping your dog’s kicking can have different costs. It will depend on the cause, and what treatment might be recommended.