If your dog is not putting weight on a back leg, it usually means they are experiencing pain, weakness, or injury severe enough to make them avoid using the limb.
Dogs hide discomfort well, so refusing to bear weight is a significant sign something is wrong.
We outline the common reasons why a dog may not put weight on a back leg, what you can do at home, and when to seek veterinary help.
Table of Contents
Dog Not Putting Weight on Back Leg: Why It Happens
A dog not putting weight on a back leg is often dealing with ligament injury, muscle strain, joint disease, hip issues, fractures, or sudden trauma that makes the limb too painful or unstable to use.
When a dog lifts or avoids using a leg entirely, it indicates either intense discomfort or mechanical dysfunction.
Dog Not Putting Weight on Back Leg: Common Causes
Cranial Cruciate Ligament (CCL) Injury
The most common orthopedic reason for a dog refusing to put weight on a back leg is a torn or partially torn cranial cruciate ligament — the canine version of the ACL in humans.
This ligament stabilizes the knee, and when it ruptures, the joint becomes unstable instantly. Dogs often yelp, lift the leg completely, and refuse to touch it to the ground afterward.
In the days that follow, swelling develops around the knee, and the dog continues holding up the leg because bending it becomes painful.
Even partial tears create enough instability that the knee feels unsafe to bear weight. Over time, untreated CCL injuries lead to arthritis, ongoing pain, and muscle loss in the affected leg.
Because dogs shift their weight to the opposite side, the second knee often becomes strained as well.
Read more: Dog Diarrhea and weak back legs (Common causes)
Muscle Strain, Sprain, or Soft Tissue Injury
Dogs can strain muscles or sprain ligaments in the back leg during running, jumping, slipping, or twisting the leg unexpectedly. Soft tissue injuries cause immediate sharp pain, causing the dog to lift the leg to avoid pressure. Muscle strains may not show swelling, but the dog will be unwilling to push off the leg or stand squarely.
This type of injury becomes more noticeable after rest, when stiff or inflamed tissues tighten. Dogs may limp mildly at first but eventually refuse to put weight on the leg if pain worsens. Soft tissue injuries require rest because continued activity prolongs the inflammation and can lead to compensatory strain in other joints.
Hip Dysplasia or Hip Arthritis
Hip dysplasia causes the hip joint to sit improperly in the socket, creating instability, inflammation, and pain.
Dogs with hip dysplasia may occasionally refuse to put weight on the affected leg when pain flares. In senior dogs, hip arthritis can lead to sudden off-loading of a leg, especially after vigorous activity or cold weather.
When the hip joint becomes inflamed enough, the dog instinctively avoids bearing weight because the joint feels unstable or painful under pressure.
Dogs may also struggle rising, hesitate on stairs, or sway in the back end. Hip-related pain can also cause referred lameness, where the dog lifts one leg even though both hips are sore.
Luxating Patella
Small breeds commonly experience luxating patella, where the kneecap slips out of place. When this happens, the dog may suddenly hop or hold the leg in the air because the knee no longer tracks correctly.
Some dogs extend the leg backward in an attempt to pop the kneecap back into position.
In mild cases, the kneecap slips back on its own, and the dog resumes walking normally. But with more advanced luxation, the kneecap may stay out of place longer, causing the dog to avoid using the leg entirely.
Over time, the joint becomes inflamed, making weight-bearing painful even after the kneecap returns to place.
Fractures, Toe Injuries, or Foot Trauma
A fracture anywhere in the leg — from the hip down to the toes — can cause a dog to immediately refuse to put weight on the limb.
Hairline fractures may allow some movement but still create intense pain. Broken toes, torn toenails, or foreign objects lodged in the paw can also make weight-bearing impossible.
Dogs may lick the injured area excessively or cry when the leg is touched. Even small injuries to the foot can feel severe because every step puts pressure on that spot. Puppies and energetic dogs are more prone to fractures due to rough play or falls.
Spinal Issues Affecting the Back Legs
Nerve problems caused by spinal disease, such as intervertebral disc disease (IVDD), can cause a dog to avoid putting weight on a back leg because the limb feels weak, numb, or unstable.
In these cases, the dog may not show obvious pain in the leg itself — instead, the nerve signals from the spine are disrupted.
Spinal problems may also cause stumbling, dragging toes, collapsing in the back end, or difficulty rising. Sudden nerve-related lameness is very serious and can worsen rapidly without intervention.
Hip Luxation or Dislocation
Severe trauma or underlying joint disease can cause the hip to pop partially or completely out of its socket. When this happens, a dog will not bear weight on the leg at all.
The leg may appear shortened, rotated outward, or held close to the body. Hip luxation is extremely painful and requires immediate attention to prevent permanent damage.
Read more: Old Dog Back Legs Collapsing (Why senior dogs lose back-end strength)
What to Do If Your Dog Is Not Putting Weight on Their Back Leg
Begin by keeping your dog as calm and still as possible. Movement or attempts to walk can worsen pain and increase inflammation. Guide your dog to a soft, comfortable resting area and restrict activity entirely for the first several hours.
Gently examine the paw and lower leg if your dog allows it. Check for broken nails, debris between the pads, small cuts, or swelling. Avoid manipulating the knee or hip, as this can worsen injuries. If your dog reacts strongly to touch or cries out, stop the exam.
Apply a cold compress wrapped in a cloth to the leg for short intervals to help reduce swelling, but do not apply ice directly. Ensure your dog avoids jumping on furniture, running, or climbing stairs — even if they attempt to use the leg again.
Do not give human pain medications. Many are dangerous for dogs and can make diagnosis more difficult. Limit food and water to prevent vomiting if pain medications become necessary during a vet visit.
A dog that refuses to bear weight usually needs veterinary care, especially if the issue persists beyond a few hours or returns after short rest.
When to Call or Visit Your Vet
Seek veterinary care promptly if your dog is not putting weight on a back leg and:
• The leg is held up completely and your dog refuses to touch it to the ground.
• There is swelling, heat, or a visibly abnormal limb position.
• Your dog yelps when the area is touched.
• The lameness started suddenly after exercise or play.
• Your dog has trouble standing, walking, or rising.
• There is no improvement after 12–24 hours of rest.
• You suspect a fracture, patella luxation, or CCL tear.
• Your dog collapses, drags the leg, or shows signs of spinal issues.
• The dog is a puppy, senior, or already has joint disease.
Early diagnosis prevents long-term complications such as arthritis, muscle wasting, or worsening injury.
Read more: Dog Throwing Up and Weak Back Legs (Causes explained)
Key Takeaway
When a dog is not putting weight on a back leg, the cause is often ligament injury, muscle strain, hip disease, patella luxation, foot trauma, or nerve issues.
Dogs lift a leg only when the pain or instability is significant, so sudden or persistent non-weight-bearing should always be taken seriously.
With prompt rest, careful observation, and veterinary evaluation, many causes can be treated effectively — helping your dog return to comfortable movement and long-term mobility.