If you notice your dog walking awkwardly, like they're stepping on the tops of their paws, this is called "dog knuckling." It's a sign that something's wrong, and it's important not to ignore it. Knuckling in dogs can have various causes ranging from neurological disorders to injuries. As a veterinarian, I frequently see dogs with this symptom. The first step is always a thorough veterinary examination to pinpoint the underlying cause. Only then we can determine the right treatment plan for your dog.

What does knuckling in dogs look like?

When a dog is knuckling, they will position their paws differently than usual. Instead of placing their paws flat on the ground, they will unknowingly stand or walk on the top part of their paw(s). They will often scuff the top part of their paws while they walk. This might happen on the front paws, hind paws, or even all four.

knuckling in dogs
Knuckling in dogs

In addition to knuckling, you may also notice that your dog drags the affected paw or has gait incoordination or balance issues that we call ataxia.

Knuckling is often a result of an abnormality within the neurological system, although orthopedic issues or injuries can also cause it. When a dog is knuckling, they may not have control over their paws and may drag them instead of lifting them normally.

You might notice that the top of their paw drags along the ground as they walk, which can cause physical injury to the paws over time. Additionally, if you have your dog stand and lift one paw at a time, they might not correct the position of their paw if they are knuckling and leave their knuckle tucked under.

What does it mean when a dog is knuckling?

When a dog is knuckling, it means they don't have full awareness of where their paws are in relation to the ground. We refer to this as a proprioceptive deficit. Knuckling signals a disruption in the dog's neurological system.

The proprioceptive pathway: Nerves in the paws send signals about position and movement up the legs, through the spinal cord, and to the brain. The brain then processes this information and sends signals back to coordinate precise movement. A disruption anywhere along this pathway could lead to knuckling in dogs.

What are the causes of knuckling in dogs?

Remember that dog knuckling is a symptom, not a diagnosis in itself. There are a range of potential causes, some more serious than others. Here's a breakdown of the most common causes that I see in practice:

1. Degenerative myelopathy (DM)

Degenerative myelopathy is one of the most common causes of knuckling in otherwise healthy dogs. It typically affects older dogs (often over 8 years old), with a higher predisposition in middle to large breeds, particularly German Shepherds.

DM is a progressive disease that gradually damages the nerves in the spinal cord. The exact cause remains unknown, but genetics are likely a risk factor. Diagnosis of DM in dogs can only be done after all other causes of knuckling have been excluded.

Knuckling is a common symptom of DM, typically starting in the back paws and progressing over time. Other signs include muscle weakness, hind leg incoordination (walking with a swaying motion), difficulty rising from a lying position, dragging the paws, and eventually, paralysis. The good news is that DM is not typically associated with pain.

Unfortunately, there's no definitive treatment or cure for DM. Treatment focuses on managing symptoms and improving the dog's quality of life. Physical therapy has been shown to be very beneficial in dogs affected by DM. Physiotherapy helps to maintain muscle strength and coordination, and supportive devices like ramps or harnesses assist with mobility.

2. Intervertebral disc disease (IVDD)

Intervertebral disc disease occurs when the cushioning discs between the vertebrae (spinal bones) rupture or bulge outwards, putting pressure on the spinal cord. This pressure disrupts nerve signals traveling between the brain and body. Factors like breed predisposition (e.g. Dachshunds and French Bulldogs), genetics, obesity, and repetitive stress on the back can increase the risk of IVDD.

Along with knuckling, IVDD symptoms can vary depending on the location and severity of the disc herniation. Signs might include pain (crying out, reluctance to jump), weakness in one or both hind legs, muscle twitches, loss of bladder or bowel control, and paralysis in severe cases.

Treatment options depend on the severity of the condition. Rest, pain medication, and anti-inflammatory drugs are often used in mild cases. More serious cases might require surgery to remove the herniated disc material. Physical therapy can also be beneficial for rehabilitation.

3. Spinal cord stroke or fibrocartilaginous embolic myelopathy (FCE)

Fibrocartilagenous embolic myelopathy is a sudden blockage of blood flow to part of the spinal cord, often caused by a fragment of disc material dislodging and traveling through the bloodstream.

Symptoms of FCE can come on suddenly and might seem quite alarming. Typically, these symptoms affect just one of the animal's legs, often a back one. You might notice the affected paw starts to knuckle under, but interestingly, this condition doesn’t typically cause pain and doesn’t get worse over time.

The main treatments for FCE are physiotherapy and supportive care. This can involve massages, gentle exercises (with or without help), muscle stimulation with special equipment, and water therapy. Dogs that can't move much need to be on soft bedding and gently moved every 4-6 hours to prevent bedsores and breathing problems.

4. Wobbler syndrome (cervical vertebral instability)

Wobbler syndrome affects the vertebrae in the neck, causing instability and compression of the spinal cord. This compression disrupts nerve signals to the body. Genetics and large breed size are predisposing factors. Great Danes and Doberman pinschers are common breeds to be affected.

Knuckling usually occurs in all limbs, with the hind limbs often more pronounced. Wobbler syndrome can cause neck pain, difficulty walking (especially on uneven terrain), swaying gait (ataxia), and weakness in the forelimbs.

If your dog is only showing mild neurological symptoms, I recommend starting with conservative treatments. However, if these symptoms are severe or if your dog is experiencing significant pain, then surgery to relieve pressure and stabilize their condition might be the best course of action.

Conservative treatments include pain medication and anti-inflammatory drugs to manage discomfort. In some cases, muscle relaxants such as methocarbamol can be effective.

5. Other conditions

While the above-mentioned neurological issues are the most common causes of knuckling, certain less-common diseases can also lead to this symptom:

  • Neurological tumors: Tumors affecting the brain or spinal cord can disrupt normal nerve signaling and cause knuckling. If there is a brain tumor, other potential signs include seizures, behavioral change, and circling may be present.
  • Metronidazole toxicity: While rare, very high doses of the antibiotic metronidazole can cause neurological side effects, including weakness, incoordination, and knuckling. These symptoms usually improve when the medication is stopped.
  • Vestibular disease: Vestibular disease affects the inner ear and balance centers in the brain. While vestibular disease more commonly causes head tilt, loss of balance, and circling, severe cases can sometimes lead to incoordination that manifests as knuckling.

If your dog is knuckling, please contact your vet immediately for an assessment. While neurological causes are the most concerning, it's important to rule out all potential underlying health concerns.

Treatment options for a dog who is knuckling

While the primary focus is to diagnose and treat the specific cause of your dog's knuckling, there are several things you can do to manage the symptom and help your dog maintain a better quality of life:

Safe flooring

Provide surfaces with good traction to help your dog walk more confidently and prevent slipping. Rubber mats, non-slip rugs, and carpet runners can be helpful.

Pain control and anti-inflammatories

Your vet might recommend anti-inflammatory medications or pain relief based on your dog's individual needs. This can be especially important for conditions like arthritis, injuries, or after surgical procedures.

Physical therapy

A qualified veterinary physiotherapist can design a personalized exercise and rehabilitation program to help your dog regain strength, and coordination, and improve their gait. This can be beneficial for a variety of causes of knuckling.

Assistive devices

Depending on your dog's specific needs, your vet might recommend assistive devices like a sling or harness to help support and stabilize their hind legs.

  • Braces and orthotics: For dogs with partial strength or recovering from injury, custom-fitted braces can provide support and correct paw positioning.
  • Harnesses and slings: Can help with mobility and lifting dogs with significant weakness, particularly after an injury or surgery.
  • Carts and wheelchairs: These offer independence for dogs with paralysis or significant weakness in multiple legs.
  • Protect the paws: Dogs who knuckle are prone to dragging and injuring their paws. Consider protective booties or keeping their nails trimmed to minimize skin damage. Inspect their paws regularly for any scrapes or injuries.

I hope this article was helpful in understanding the causes and treatment options for knuckling in dogs. Remember, early intervention can greatly improve your dog's quality of life and prevent further progression of this condition. If you notice your dog knuckling every step they take, it's vital to act quickly. With proper care and treatment, your dog has the potential to regain strength and mobility in their hind legs. Remember always to call your vet if you are concerned about the health of your pets.