Dog Hind Leg Weakness: What It Means and What to Do Next

Dog hind leg weakness: what it means and what to do next

If your dog's back end is getting wobbly, remember that hind leg weakness is a sign rather than a diagnosis: in one Miniature Schnauzer, back leg weakness and incoordination that came on quickly and kept worsening turned out to be caused by a fungal granuloma, a lump of inflamed tissue from a fungal infection, inside the spinal cord.¹ Gradual wobbliness needs an appointment soon. Back legs that fail suddenly, or a dog who cannot stand or move them at all, is an emergency and needs a vet the same day.

For the bigger picture of what can go wrong back there, start with our overview of back leg problems in dogs and the main hub on weak back legs. This page is about sorting out what you are seeing and what to do this week.

Why do dogs' hind legs get weak?

Joints and ligaments. Rupture of the cranial cruciate ligament, the main stabilising ligament inside the knee, is the most common orthopaedic condition in dogs, and it is diagnosed by feeling for a "cranial drawer" sign, meaning the knee shifts in a way a stable joint does not.² Hips matter too. In one group of 466 dogs having knee surgery, hip dysplasia, a poorly fitting hip joint, showed up on x-rays in about 36% of them; 74% of those dogs also had x-ray signs of osteoarthritis, and more severe dysplasia was strongly linked to more severe arthritis.³

Spine and spinal cord. Dogs are treated for back legs that suddenly become too weak to walk on, or that lose movement altogether, because of a herniated disc, where the cushion between two spine bones bulges or bursts and presses on the spinal cord.⁴ Complete paralysis of both back legs is the most severe grade of spinal cord injury in dogs, ranking above weak-but-still-walking and too-weak-to-walk.⁵ Other things can press on or inflame the spinal cord: one 4-year-old Golden Retriever had long-standing, slowly worsening back leg function caused by a painless fluid-filled lesion squeezing the spinal cord in the chest region, and another dog had mild back leg weakness caused by a fatty tumour that had grown into the vertebrae and spinal canal.⁶⁷

Blood supply to the legs. In a study of 42 dogs with ischemic neuromyopathy, a condition where loss of blood flow to a limb damages nerves and muscle, 38 of the 42 dogs (90.5%) had the problem in a back limb.⁸ Most of those dogs had another illness going on at the same time, most often a kidney condition that leaks protein.⁸

Weak when getting up, versus weak all at once

Tell your vet how quickly the signs came on, because in dogs with this loss of blood flow to a back limb, a more gradual slide to peak severity was associated with a better chance of surviving to discharge.⁸

In Miniature American Shepherds with neuroaxonal dystrophy, an inherited disease in which nerve fibres gradually break down, young adult dogs develop hind limb weakness and an unsteady, wobbly gait that worsens over time.⁹ The Golden Retriever above showed the same slow pattern, with back leg movement declining steadily over months.⁶

Fast is different. One 7-year-old Miniature Schnauzer had a sudden, worsening history of back leg weakness and incoordination,¹ and went from unable to walk to complete paralysis of both back legs within 24 hours.¹ Hours matter in cases like that. If your dog's back legs are very weak today and were normal yesterday, do not wait for a routine slot.

If the legs are collapsing under your dog rather than just trembling, our guide on back legs that are weak and giving out walks through what to note down before the appointment.

When one hind leg is weak, not both

Masses can also sit in one leg: in 29 dogs treated for infiltrative lipomas, a fatty growth that spreads into surrounding tissue, the back leg was the most common location (41%), usually in the thigh.¹⁰

Either way, one weak back leg is worth an exam rather than a wait-and-see.

Weak back legs in a puppy or young dog

Some are inherited nerve diseases: in Miniature American Shepherds, a single missing letter in a gene called RNF170 causes neuroaxonal dystrophy, and affected dogs are typically young adults with back leg weakness and an unsteady gait.⁹ The fault is passed on only when both parents carry it.⁹

It is seen most often in the lower back of screw-tail breeds like bulldogs, and as bulldogs have become more popular these cases are being seen more often.¹¹ Signs can include urinary or faecal incontinence, back leg deficits with a bunny-hopping gait, and skin changes over the spine such as a swirl of hair and a dimple.¹¹

If you have a young dog with a weak back end, say so clearly at the appointment. It changes what your vet looks for.

Protect your dog from falls while you are waiting

Weak back legs and stairs are a bad mix. Among 61 dogs brought to emergency centres after falling down stairs, spinal cord injuries ranged from mild (still walking but weak behind) in 18% of cases, to unable to walk in 11%, to full back leg paralysis in 5%.⁵ The authors also noted it can be hard to tell whether the fall caused the injury or whether an existing problem caused the fall.⁵ Block the stairs, add traction on slick floors, and support the back end with a towel sling under the belly until you have a plan. The reassuring part: 74% of those dogs went home from the hospital.⁵

Can a dog recover from hind leg weakness?

Sometimes, yes. In the study of dogs whose back limb lost its blood supply, 7 of 28 dogs with long-term follow-up recovered fully, including 2 of 16 that could not walk at first.⁸ The authors concluded that recovery can happen despite severe nerve problems at the start, so prognosis should never rest on one finding alone.⁸

Your vet may also raise rehab and add-on care. One evidence review found moderate evidence for a mild benefit from acupuncture alongside medical treatment in dogs recovering from a burst disc in the mid to lower back.¹² What helps depends entirely on the diagnosis, which is your vet's call. For more on timelines and what "recovery" realistically looks like, read whether a dog can recover from hind leg weakness.

Where a wheelchair fits in

A wheelchair does not treat anything. What it does is carry the back end so your dog can move, sniff and go outside while your vet handles the medical side.

The OldPal Rear Support Dog Wheelchair is built for dogs with weak or failing back legs. The padded harness carries weight through the hips and chest rather than the spine, every strap adjusts, and the frame is set so the back legs hang free or lightly brush the ground. Dogs can squat and go to the bathroom while in the chair. The frame is lightweight aluminium with all-terrain wheels, and it adjusts in height within its range.

Sizing is simple. One measurement does it: rear leg height, from the top of the hip straight down to the toe pad, taken with your dog lying on its side and the leg at its natural bend. Five sizes (Mini, Small, Medium, Large, XL) cover rear leg heights from 3 to 31 inches.

Measure your dog, then choose a size: use the size guide and fit finder, then order the rear support wheelchair. If the size is wrong, our Fit Guarantee means we replace it with the one that fits and return shipping is your only cost. Most orders arrive within 2 to 3 weeks, continental US only. Not sure? Email a photo and your measurement to help@oldpalpets.com and a person will answer.

Frequently asked questions

Related guides

• When back legs are weak and giving out

Good Days Ahead.

Sources