Knuckling in Dogs

Knuckling is when the top of your dog’s paw drags along the ground as they are walking. It is generally a neurological problem. Common reasons for this behavior may include:

• Sore paws
• Intervertebral disc disease
• Carpal flexural deformity
• Fibrocartilaginous embolism
• Degenerative myelopathy

These causes can range from minor to serious, and should be checked by a veterinarian to be safe. Some of the illnesses can be serious and in some cases fatal, whereas others can improve with time. Some of these illnesses can have positive outcomes with satisfactory recoveries, as long as they are treated promptly and properly.

You should observe your dog while they are walking away and toward you and look out for any signs of unsteadiness or an uneven gait. You can determine if your dog is knuckling over by having them stand and one at a time lifting their paws and placing them down with the knuckle under. Your dog should immediately correct the position of their paw, and if they do not it is likely that they are, for some reason, knuckling.

Sore Paws

If the knuckling occurs suddenly, check your pet’s paws as they may have a sharp object such as a thorn embedded in their foot, which can cause pain as they are walking. Burns from hot pavement can also have the same effect. Other possible causes include bug bites on the paws or broken toes and claws. Your dog should be taken to the veterinarian if the issue does not resolve within a day, as some objects can cause infections if not taken out and treated.

Intervertebral Disc Disease

This disease occurs when the disc in your dog’s spinal cord begin to degenerate. This is generally a factor of age, but can also occur in younger dogs due to physical trauma or strenuous activity. Accidents like getting hit by a car or fighting with another animal can also bring on IVDD. Signs can vary but in general the dog may begin stumbling, knuckling their paws, showing stiffness and holding their head low, sensitivity to touch and movement, arching their back, showing lameness, weakness, a reluctance to move, shaking, loss of coordination and collapsing, potentially paralysis on one or more limbs and overall walking oddly. In mild cases, steroids and anti-inflammatories can help treat it, but surgery may be needed for more severe cases. Some breeds that are predisposed due to a disorder of cartilage formation, called chondrodystrophy, are Bulldogs, Basset Hounds, Dachshunds, Corgis, Beagles, Cocker Spaniels, Shih-Tzus, Poodles and Pekingese. Other breeds that are commonly affected are German Shepherds, Doberman Pinschers and Labrador Retrievers. Dogs who are of these breeds and are obese are of further risk.

Carpal Flexural Deformity

This can occur in puppies as they go through growth spurts. Any dog can develop carpal flexural deformity, although it is commonly seen in larger breeds, sometimes caused by an excess of protein. Your veterinarian can assist you in determining the correct diet for your pet. Generally, puppies who are under 4 months of age may show signs of over flexing or bulging their wrists forward. In many cases, the dog’s wrists will straighten out on their own within a few weeks and will not require treatment, but seeing a veterinarian would be wise as your dog could develop a lifelong deformity.

Fibrocartilaginous Embolism

This is a spinal condition that can be seen in any dog but is more commonly found in larger breeds. The cause of fibrocartilaginous embolism is a piece of intervertebral disc that detaches and ends up in a blood vessel. This can lead to a blood clot or an embolism, which cuts off the supply of blood and oxygen to that part of the spinal cord and can cause the tissues to die. Dogs that develop fibrocartilaginous embolism may yelp once, but will then may show no further signs of pain. They will then lose functionality of one or several limbs without much warning. Dogs with this illness may or may not see improvements, but will rarely experience a worsening in the signs.

Degenerative Myelopathy

Older dogs who begin knuckling over can be lame, experiencing arthritis or developing degenerative myelopathy. The latter occurs when there is a loss of white matter that is sheathing the spinal cord, also known as myelin. Dogs will most likely develop this disease between the ages of 8 to 14 The signs will begin with a loss of coordination in the hind limbs. The dog will wobble, drag their feet and the rear paws will knuckle over, often noticed when they are attempting to turn. Some other signs of this disease will include them falling frequently and showing difficulty rising. This disease is not painful but is progressive and can continue to get worse. It can take 6 months to 1 year for the disease to progress until the point that the dog is unable to walk, sadly.  

Ideally, dogs with sore paws due to cuts or scratches would rest and let it heal. However, dogs are active and will often continue to move around and therefore reopen their wound. If the cut looks deep, they should be taken to a veterinarian. If it is a small scratch, you should examine the paw and look out for broken nails, which can also be a source of bleeding. The wound can then be washed with warm water and any debris should be removed using tweezers or dislodged by soaking the paw in a bowl of warm water. The area can be cleaned with a diluted antiseptic and antiseptic cream should be applied.  If there is excessive oozing or bleeding, sores on the pads, toenails with crusting at the base, thick callouses or deep cracks, you should contact a veterinarian. 

Intervertebral disc disease can require treatments varying from rest and medical management to surgery, depending on the severity. The first priority will be to manage the inflammation and the pain. Your veterinarian may suggest either nonsteroidal anti-inflammatory medications, corticosteroids, narcotics, muscle relaxants or other medications along with restricted movement and rest. If these drugs do not alleviate the pain, surgery may be required. Three to six weeks of consistent cage confinement is essential for a full recovery in all cases. Your pet should be placed on a soft surface and will need to be turned every few hours in order to prevent pressure sores from developing. Overweight dogs will be put on a dietary program. Other techniques, such as massage therapy, acupressure or acupuncture, supplements and other supportive care can also be beneficial. If your puppy is knuckling, stop feeding them milk and meat as high protein can worsen the carpal flexural deformity - make sure you are feeding a balanced puppy food. Fibrocartilaginous embolism may require an MRI in order to be diagnosed. CT scans and spinal radiographs can also be beneficial. FCE is not easily treated, and recovery will usually rely on time for the spinal cord to create new blood vessels or open up the ones that were affected. While recovering, dogs should be resting on a soft bed and rotated every few hours. Physical therapy can help in the recovery phase, along with acupuncture, laser therapy and hyperbaric oxygen therapy. In some cases, the patient will be able to walk in 2 to 6 weeks. Degenerative myelopathy is diagnosed by a process of elimination. Diagnostic tests and MRIs may be used to look for other sources of the signs, and once ruled out, it may be decided that the pet has degenerative myelopathy. Sadly, this illness does not have any known treatments or ways of slowing the progression. However, the dog’s quality of life can be improved by nursing care, prevention of pressure sores, monitoring for urinary tract infections, using carts and harnesses to facilitate mobility, and physical rehabilitation.

To keep your dog from developing IVDD, keep their activity and exercise levels under control. This means that you should not allow them to run or jump excessively. If your dog is predisposed, do not let them leap off of high surfaces, and obesity should always be avoided.

Your dog’s foot pads need protection from the heat and cold, as they can burn on hot pavement and can get irritated by the ice and salt in the wintertime. Dog boots are a good way to prevent sore paws during the hot and cold months. Special foot wax is another option. You should also keep your pet’s hair in their paws short, as it will help keep out objects like grass seeds, and will help you clearly see any objects that are stuck in the pads. If your puppy is knuckling and has carpal flexural deformity, keep them quiet and away from any activity that will challenge their mobility, including going up and down stairs frequently, until they are fully recovered. Carpal flexural deformity can be prevented by properly weaning puppies before separating them from their mothers. Let the puppies out in places that they can run, dig, and use their muscles properly. 

All of these causes of knuckling can have different outcomes and different costs for treatment. Intervertebral disc disease has a treatment cost of  between $150 to $9000, and curing carpal hyperextension can cost $1500. Fibrocartilaginous embolic myelopathy can cost between $500 and $4000 to treat, and treating degenerative myelopathy will depend on the medications and therapy needed.