Vet’s Top 5 Reasons Your Older Dog’s Back Legs Are Collapsing & Weak

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Hind leg weakness can cause an old dog’s back legs to collapse, decreasing their quality of life. This common condition is caused by a variety of diseases, including osteoarthritis, degenerative myelopathy, lumbosacral instability, intervertebral disc disease, and systemic illnesses. 

I’m a veterinarian and in this article, I’ll cover the symptoms and treatments for the top four causes of hind leg weakness in dogs.

You’ll also learn about home care to help your dog, including tips on adapting your home to help them walk better, assistive devices and how to strengthen their back legs.

The most common diseases that cause an elderly dog’s back legs to collapse include 

  • Osteoarthritis
  • Degenerative myelopathy
  • Lumbosacral instability
  • Intervertebral disc disease
  • Other systemic diseases (anemia, heart/liver/kidney disease, diabetes, etc.)

I want to go into more detail to help you understand these causes of back leg weakness in dogs. You should work with your veterinarian to get a diagnosis and determine the best treatment for your unique pet.

In the second part of the article, I’ll discuss practical home care tips you can use to help your dog adapt.

Symptoms to Watch for

Hind leg weakness may develop gradually in seniors. Here are some of the most common symptoms to watch for:

  • Back legs weak and shaking/trembling
  • Stumbling or tripping
  • Drags back feet when walking
  • Slower going up stairs
  • Jumping on furniture less
  • Slow getting up from lying down
  • Doesn’t want to run as much as before
  • Reluctant to jump into the car
  • Worn down toenails on back feet from scuffing
  • Thigh/hip muscle atrophy
  • Change in tail position
  • Falling more often with legs splayed
  • Back legs become spastic/ involuntary kicking
  • Takes smaller steps with back feet

Causes of Collapsing Back Legs in Old Dogs

Osteoarthritis

At least 25% of dogs will be diagnosed with arthritis/osteoarthritis (OA) during their lifetime and up to 60% have evidence of OA on x-rays (2). OA happens when the cartilage in joints breaks down which leads to inflammation and pain. OA can affect any joint, but the large joints in the legs are frequently affected. 

Large breed dogs tend to get osteoarthritis at an earlier age than small breed dogs. Certain breeds have a higher likelihood of inheriting orthopedic abnormalities like hip dysplasia. My friend over at WorldofDogz.com has a great article about hip dysplasia in German Shepherds but the advice applies to all breeds.

Breeds Affected

  • German Shepherd
  • Labrador Retriever
  • Golden Retriever
  • Rottweiler
  • Mastiff

Dogs with advanced hip or knee arthritis are likely to have weak hind legs, trouble walking and sometimes can’t get up on their back legs without help. Pain leads to decreased activity, which leads to loss of muscle mass and even more hind end weakness. 

Dogs with arthritis may not show obvious signs of pain, but you can see they are painful by the way they stand, the way they walk and the way they have trouble getting up and down from a lying position. They tend to be very stiff-gaited when they first stand up after lying down for a while, but they become less stiff as they move around. You may hear “crackling” sounds when you manually manipulate the dog’s knee or hip. 

All breeds of dogs, including mixed breeds, are affected by OA. The older a dog is, the more likely they are to have some degree of osteoarthritis. 

Treatment

Treatment for canine arthritis has come a long way in the last few decades. We have many treatment options from oral medications and supplements to stem cell and physical therapy.

Nutritional supplements seem to help in some cases. Vets may recommend glucosamine, UCII (undenatured collagen), fish oil, and turmeric. Discuss these options with your veterinarian to find the best combination for your unique dog.

The key points to remember in canine osteoarthritis are to keep their weight down, keep them moving, and treat their pain. Most dogs with arthritis can live a comfortable life with diligent monitoring and appropriate medical care. 

Degenerative Myelopathy

Canine degenerative myelopathy (DM) is an inherited abnormality of the nervous system that causes progressive back leg weakness in older dogs. Puppies inherit a genetic mutation from their parents that puts them at risk for developing DM. (3).

DM has been compared to Lou Gehrig’s disease in humans (1). DM also occurs in mixed breed dogs. People usually first notice occasional dragging of back feet that progresses to an inability to walk.

Breeds Affected

  • German Shepherds
  • Pembroke and Cardigan Welsh Corgis
  • Standard Poodles
  • Pugs
  • Collies
  • Boxers

A diagnosis of DM is based on clinical symptoms, a vet exam, blood testing, and radiographs (x-rays). In some cases, electromyogram (muscle testing), spinal taps and CT/MRI help confirm the diagnosis. In the real world, vets depend on ruling out other causes for an old dog’s hind legs collapsing to make a diagnosis.

Dogs 8 years and older are more likely to show symptoms of DM. Early signs include difficulty jumping, weakness in the dog’s back legs including collapsing, stumbling, splaying out, slipping, “crossing-over” of rear feet, worn down toenails and abrasions on the feet from scuffing. DM is not known to cause pain and most dogs don’t seem distressed in the early stages of the condition.

In the early stages, this disease may be difficult to differentiate from osteoarthritis and disc disease. Inflammatory diseases including bacterial infection, fungal infection and cancer affecting the dog’s spinal cord cause symptoms very similar to DM.

Treatment

Tragically, there are no proven effective treatments for DM at this time and the long-term prognosis is poor. Most dogs lose the ability to walk within 6-12 months of diagnosis. 

Urination and defecation difficulties are major considerations in caring for dogs with DM. Difficulties dealing with these challenges lead most dog owners to have their affected pets euthanized within 18 months. Smaller breeds are more easily managed for longer periods of time.

dog back legs weak
Common symptom of dog back legs weakness… a dog’s back paw with worn nails

Lumbosacral Instability in Dogs

Also known as cauda equina syndrome, lumbosacral stenosis, lumbosacral instability, this problem affects the space between a dog’s last vertebrae and sacrum. If you’re looking at your dog, the lumbosacral (LS) area is in his lower back, just behind the two pelvic bones that stand out in that area. Instability in this area leads to abnormal movement of the bones and pinched nerves. 

The symptoms of lumbosacral disease in dogs depend on which nerves are affected. Some dogs have weakness and shaking (from pain) while others tend to experience limping more than collapsing. Urinary and fecal incontinence are common in addition to decreased muscle tone and sensation to the tail. Dogs may cry out or flinch when touched around the lower back, tail and back legs. 

X-ray of a dog's lower back with new bone formation at the lumbosacral junction. (old dogs back legs collapsing)
Radiograph of a dog with lumbosacral disease

Breeds Affected

  • Airedale
  • Boxer
  • German Shepherds
  • Golden Retriever
  • Great Dane
  • Labrador Retriever

Treatment

Treatment for LS trouble is often a matter of pain management and avoidance of activities like running and jumping. Surgery can help stabilize the lumbosacral joint, but due to the advanced age of most dogs and the chronic changes present, surgery is not as common as medical treatment. 

Steroids may be used for dogs with acute, severe pain and weakness, but non-steroidal anti-inflammatory drugs (NSAIDs) are used for long-term management. Acupuncture and cold laser therapy may relieve pain during flare-ups.

One of my dogs has suffered from LS disease for over five years. She has stretches of time where she is quite comfortable thanks to nutritional supplements, regular moderate exercise, NSAIDs and pain medicines. Every couple of years she has a bad flare of pain and it can take months for her to return to normal. 

I try to keep her from jumping and running since those activities cause her pain the next day. She’s a healthy dog in every other way, it’s just something we have to manage. 

old dogs back legs collapsing - an old dog with physical signs of thigh muscle atrophy and toe dragging
Hallmarks of chronic neurologic problems that are the cause of an old dogs back legs collapsing.

Intervertebral Disc Disease

Intervertebral disc disease (IVDD) in dogs is a common cause of back pain and, in severe cases, can cause back leg weakness in dogs. IVDD happens when the disc cushion between the bones of the spine breaks down and presses on nerves branching off the spinal cord.

The most common locations for IVDD in dogs are the neck and the mid-to-lower back (thoracolumbar area). Dogs with IVDD in the thoracolumbar area sometimes have weak rear legs and panting due to pain early in the process. In severe cases, you might see paralysis of a dog’s back legs.

IVDD is common in adult dogs of all ages, but older dogs may be more severely affected.  

Breeds Affected

  • American Cocker Spaniel
  • Bassett Hound
  • Beagle
  • Corgi
  • Dachshund
  • German Shepherd
  • Shih Tzu

Radiographs can sometimes identify IVDD lesions, but special imaging like MRI or a myelogram is needed to know for sure. Special imaging is usually done by a vet specialist and requires the dog to be under anesthesia

Treatment

IVDD treatment depends on the severity of the symptoms. For mildly affected dogs with pain only and no weakness, strict rest and anti-inflammatories bring improvement within a week or two.

Dogs who are stumbling, cannot stand, or have significant hind end weakness may improve with rest and medication prescribed by a vet. It can take dogs like this weeks to months to recover. Your vet will advise you that dogs with paralysis of their hind limbs are good candidates for surgery.

You can read much more about IVDD symptoms, treatment and prognosis in my article on the topic. 

Home Care Tips

There are many things you can do to help your senior dog maintain his quality of life despite a change in mobility. Here are a few ideas used by my clients and myself…

  • Adaptive furnishings like carpet runners for slick floors
  • Braces, socks and booties
  • Plastic nail caps
  • Dog wheelchairs
  • Assistive vests and rear leg protectors
  • Dealing with incontinence

Carpet Runners Make Slick Floors Easier for Dogs to Walk On

Slick wood and tile are tough for dogs with rear limb problems to stand and walk on. Many elderly dogs wind up struggling with their back legs splayed out, trying to get a grip.

The first thing you can do is install inexpensive carpet runners throughout your house. Make sure to put one anywhere your dog usually walks. Some home improvement stores sell carpet runners by the yard from rolls.

I love these carpet runners from Amazon because they come in different colors and sizes and have a non-slip backing. 

Several gray runner rugs on a slippery tile floor to help dogs with weak back legs walk more easily.
I use multiple carpet runners on my tile floor to keep my old dogs back legs from slipping

Braces, Socks & Booties

Some of my clients have tried braces that are applied on the dog’s back legs to provide mechanical support. The main challenge with leg braces is that they slip out of place. Too loose and the brace does nothing but irritate the dog. And if you tighten it too much, it can cut off circulation and cause serious injuries.

For that reason, soft socks or booties are popular. They work alright when they’re on the foot, but most people report they have a hard time getting them to stay on the foot when the dog is collapsing or dragging their feet. 

Plastic Toenail Caps

Check out these soft plastic caps for your dog’s toenails that help him get a better grip on slick floors. The main challenges with nail caps are 1) some dogs hate having their toes handled, and 2) the caps may fall off prematurely.

I’m doubtful about the utility of paw grip products that are stuck directly to a dog’s paw pad. I think it would be too hard for most people to put on and again, some dogs really hate having their feet messed with!

Dog Wheelchairs

Some of my clients have had great experiences with wheeled carts like the ones made by Walkin’ Wheels. Dog “wheelchairs” are made to support a dog’s rear legs so they can walk normally with their front legs.

Most dogs adapt well to these and seem perfectly happy to zoom around with the help of their wheels! 

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Other Devices to Help Dogs with Weak Back Legs

Some dogs prefer to go without a wheelchair, especially indoors. For them, a “drag bag” can help protect the back half of their body from abrasions. These work better for dogs under 25 pounds or so, but it doesn’t hurt to give it a try with larger dogs. 

The best device I’ve seen for dogs who can still walk but need help getting up or going up stairs, etc. is a vest that has a handle on the top. Dogs can wear the vest most of the time and you can easily grab the handle to give a little extra help when needed. 

Dealing with Incontinence

It’s pretty alarming to watch your dog’s back legs giving out more and more as time passes. Dogs often reach the point that they’re passing stool and urine in the house. Many clients report their dog is very upset by it, too.

Before you panic, first, figure out if he just can’t get outside fast enough to potty there. If that’s the case, he might need more or better pain treatments. Make sure you help him get outside frequently throughout the day even if he doesn’t act like he needs to go. 

If urine and/or stool are dribbling out while your dog is walking, and he seems unaware of it, that’s more likely true incontinence.

If he is incontinent, you can use diapers with a hole cut for his tail, or purchase special diapers made for dogs. You need to change these frequently because just like babies, dogs will get dermatitis from having a soiled diaper on for too long.

BONUS: How to Strengthen an Old Dog’s Hind Legs

It is sometimes possible to strengthen a dog’s hind legs. It’s very important to make sure their pain is adequately controlled before starting a rehabilitation regime.

I recommend you find a veterinarian trained in physical therapy and rehabilitation for the best outcome (link to find one), but you can get started on your own with the following tips.

  1. Take slow walks every day. Even though he might need a few minute to warm up, regular walking will build and maintain muscle tone and nerve signals to your dog’s hind legs. Make the walks short enough that your dog is not sore the next day. 
  2. Swimming is good exercise as long as the season is right and your dog is willing. Don’t overdo it. Some dogs get so excited about swimming they end up in a lot of pain later. 
  3. Stretching. Move your dog’s limbs through their normal range of motion while she’s laying down to keep her limber. Check out this awesome book on how to stretch your dog: The Healthy Way to Stretch Your Dog. My dogs love it!

Summary

Hind leg weakness is common in dogs, especially those over the age 10 years of age. The most common causes include joint pain from arthritis and spinal instability. These conditions are treatable and aggressive treatment often improves a dog’s mobility significantly.

It’s important to work with your veterinarian to get an accurate diagnosis so the best treatment can be prescribed. After therapy is started, it’s important to monitor the response and make any needed adjustments as symptoms change.

You can also improve your dog’s quality of life with some simple changes to your home and routine. Mobility changes don’t have to be the end of a dog’s happy days!

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References

  1. Awano, T., Johnson, G. S., Wade, C. M., Katz, M. L., Johnson, G. C., Taylor, J. F., … & March, P. A. (2009). Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy that resembles amyotrophic lateral sclerosis. Proceedings of the National Academy of Sciences, 106(8), 2794-2799.
  2. Bland, S. D. (2015). Canine osteoarthritis and treatments: a review. Veterinary Science Development.
  3. Coates JR and Wininger FA: Canine Degenerative Myelopathy. Vet Clin North Am Small Anim Pract 2010 Vol 40 pp. 929-50.
  4. Shelton, G. D., Schule, A., & Kass, P. H. (1997). Risk factors for acquired myasthenia gravis in dogs: 1,154 cases (1991-1995). Journal of the American Veterinary Medical Association, 211(11), 1428-1431.

Last update on 2023-03-29 / Affiliate links / Images from Amazon Product Advertising API