Why Are My Cat’s Back Legs Not Working (Weak, Wobbly, and Stiff)?

Mobility problems in cats immediately present themselves. Consequently, cats with wobbly or weak hind legs will have trouble walking, climbing, and jumping. Back leg stiffness is most common in older cats, but it can also affect younger cats and kittens.

Osteoarthritis is the most common cause of back leg stiffness in cats aged 10+. Cats can also develop weak and wobbly legs due to injury/trauma or falling from a height. Diabetes, organ failure, and neurological problems can cause the gradual weakening of a cat’s rear legs. If your cat’s hind legs suddenly stop working, this can sometimes signify a blood clot, infection, or stroke.

Cats are good at hiding that they’re in pain, which is an evolutionary adaptation designed to prevent sick and vulnerable cats from being singled out by predators. However, when a cat has problems walking or putting weight on its back legs, it’s much harder to hide the discomfort.

Rear Leg Problems in Cats

Weakness and stiffness can be due to bone, ligament, muscle problems, nerve damage, neurological issues, or organ failure. It can be triggered by injury (sprains, strains, and broken bones) or by a progressive disease, such as arthritis.

Weak and stiff back legs in cats can come on suddenly or more gradually. The symptoms include:

• Lameness (limping)
• Struggling to stand
• Slow or stiff walking
• Unsteady back legs
• Holding a leg off the floor while standing
• Dragging the back paws
• Legs giving out or collapsing
• Paralysis – unable to move the legs at all
• Reluctance to exercise, jump, or climb
• Disinterest in play
• Unusual vocalization, such as yowling
• Lethargy
• Sleeping more than usual
• Overgrooming of the legs or hips due to pain
• Undergrooming due to not being able to lift the legs

Toilet accidents are common when a cat can’t move its legs properly. The cat may find it difficult or painful to climb in or out of the litter box. You might also notice that your cat is more aggressive or depressed than usual.

Gradual Onset Hind Leg Problems in Cats

Various conditions can cause a slow, gradual weakening or stiffening of a cat’s rear legs. You’ll notice that your cat finds it more difficult to walk as time passes. Some conditions can develop over weeks, months, or even years.

Older cats aged 10 or older are most likely to experience such problems. However, you shouldn’t brush off rear leg weakness or stiffness as just old age. Old age is harmless, but it makes cats more prone to developing certain medical conditions.

Degenerative conditions such as arthritis cause the gradual onset of hind leg problems in cats. However, some culprits, such as brain tumors and kidney disease, can be fatal if left untreated.

Arthritis

Arthritis is a degenerative joint disease. It’s characterized by inflammation and deterioration of the joints, making movement painful, slow, and more difficult. Arthritis is mostly seen in older cats, although it can affect cats of all ages.

Usually, arthritis is caused by age-related wear and tear, but some cats are more prone to it than others due to genetics. Arthritis can also develop following an infection or leg trauma. 

Feline arthritis can be mild or severe. Severe cases are rarer than mild ones, but arthritis will worsen over the years.

The symptoms of arthritis come on slowly and may include:

• Stiff legs or limping when walking
• Lethargy
• Reluctance to climb, jump, and play
• Toilet accidents due to difficulty getting in and out of the litter box
• Reduced grooming or over-grooming to self-soothe pain
• Changes in personality, such as becoming more aggressive
• Signs of discomfort when being picked up, held, or brushed

Research suggests that arthritis is as prevalent in cats as in people. According to the  American Veterinary Medical Association, up to 90% of cats over 12 years old show signs of arthritis.

Vets diagnose arthritis using radiographs and physical examinations. Although there’s no cure for arthritis, the painful symptoms can be alleviated and made more manageable.

For example, weight loss can ease pressure on the joints, and pain medications can reduce discomfort.

Hip Dysplasia

Hip dysplasia is a genetic disorder that causes a cat’s hip bones to develop improperly.

The ball and socket joint is misaligned, preventing the ball from moving smoothly in the socket. It’s a hereditary condition that’s passed down from parent to kitten.

Maine coons, Persians, and Himalayan cats are more likely to experience hip dysplasia, while mixed-breed cats are least likely to be affected. Although present from birth, it’s often not diagnosed until later in life.

The early years of a cat’s life may be symptom-free. However, the ball grinding in the socket causes wear and tear on both bones. Eventually, the hip joint becomes loose.

The symptoms of hip dysplasia in cats include:

• Limping
• Walking stiffly or awkwardly
• Weakness in the back legs
• Obvious discomfort when the hips are touched
• Reluctance to walk, play, or climb
• Obsessive licking or chewing on the back legs or hip area

The complications of hip dysplasia can begin at any age and will worsen with time. This may be the explanation if you have a purebred cat with weak, wobbly, or stiff back legs. It’s diagnosed through scans, such as x-rays.

Anti-inflammatory drugs and pain medication can provide relief for cats with hip dysplasia. Severe cases may require a hip replacement.

Muscle Wasting

Rear leg weakness and wobbliness can also be attributed to muscle damage, which can be triggered by direct muscle trauma (such as a fight or fall) or overexertion. But if your cat’s problem is getting slowly worse over time, it may be down to muscle wasting.

Muscle wasting, also known as atrophy, refers to a loss of muscle mass. It happens when the muscles slowly degrade over time, and it can have many causes. For example:

• Nutritional deficiencies. Cats need vitamins and minerals, such as vitamin A and potassium, to maintain their muscle mass. They also need a diet that’s rich in quality protein.
• Cachexia. This is muscle loss triggered by a long-term illness or untreated injury.
• Sarcopenia. This is age-related muscle loss. According to the Companion Animal Nutrition Summit, around 38% of older cats have sarcopenia.

A vet will assess your cat’s muscle condition score (MCS) to diagnose muscle wasting. This can be done by palpating (feeling) the cat’s muscles.

The veterinarian will have to run tests, such as blood tests, to identify the cause. Often, muscle wasting can be improved by improving the cat’s nutrition and increasing its exercise level.

Neurological Issues

Neurological issues can also cause rear leg problems in cats. In particular, damage to the brain’s motor cortex.

The motor cortex is the area of the brain responsible for voluntary movement, and it’s involved with all stages of movement: planning, control, and execution. If it’s damaged through trauma or disease, a cat’s balance, strength, and walking ability can deteriorate.

According to Brain Research Reviews, a cat with a damaged motor cortex might drag its paws. It may also have trouble controlling its leg movements and stepping over obstacles. It may also develop muscle weakness or unsteadiness on the feet that worsens with time.

Damage to the brain through trauma usually causes a sudden and obvious change. However, some neurological problems develop slowly and cause issues that worsen over time. For example:

• Benign brain tumors
• Brain cancer
• Neuromuscular diseases
• Motor neuron disease
• Infection of the brain tissue

Neurological issues can be diagnosed using brain scans. Some illnesses, such as infections, can sometimes be cured. Others, such as malignant brain tumors, will often be fatal.

Heart Disease

There are many different feline heart abnormalities. One of the most common kinds is cardiomyopathy, which is a disease of the heart muscle.

It makes it difficult for the heart to circulate blood, so certain body parts receive inadequate oxygenation. If untreated, heart disease can eventually cause heart failure, which is life-threatening.

Some cats are born with heart disease. This is called congenital heart disease; it can be random or inherited from the parents. Acquired heart disease develops later in life and is more common in older cats. It can be triggered by an injury, infection, or wear and tear on the heart muscle.

Heart disease can cause a gradual weakening of a cat’s back legs if inadequate blood flow reaches the legs, and it can also lead to sudden paralysis of the hind limbs. Other symptoms of heart disease include:

• Lethargy
• Reluctance to exercise
• Shortness of breath or fast breathing
• Fainting
• Coughing
• Fast heart rate

If a veterinarian suspects heart disease, they will listen to the cat’s heart with a stethoscope. Scans such as ultrasounds, echocardiograms, and x-rays can be used to confirm the diagnosis. There is no cure for heart disease.

Feline Diabetes

Diabetes mellitus is caused by the underproduction of insulin or the body responding incorrectly to it (insulin resistance). About 1 in 230 cats will develop diabetes in their lifetime, but it’s most common in obese cats and cats aged over 7.

The first signs of feline diabetes are often hard to spot as it progresses gradually and may go unnoticed for months. Symptoms include:

• Noticeable weight loss or weight gain
• Increased thirst and urination
• Increased appetite or no appetite at all

If the disease is left to progress untreated, muscle damage and nerve damage can occur. This is called diabetic neuropathy, which results in weakness, unsteady gait, and wobbly back legs. You may notice the cat has trouble jumping and climbing.

Feline diabetes is managed through a low-carbohydrate diet and regular administration of insulin. However, it can be life-threatening if left untreated. If your cat shows signs of diabetes, a veterinarian can conduct a diagnostic blood sugar test.

Chronic Kidney Disease

Chronic kidney disease is a condition in which the kidneys slowly stop working. According to the Journal of Small Animal Practice, it’s most common in cats over 15.

It’s the role of the kidneys to filter the blood and get rid of toxins. Without this important process, the cat is gradually being poisoned. A cat with chronic kidney failure will slowly become less well.

Symptoms of kidney disease in cats start mild but worsen with time. You may notice the following signs:

• Poor appetite
• Increased urination and thirst
• Weight loss
• Vomiting
• Bad breath
• Constipation
• Brown tongue

As the disease progresses, muscle weakness and pain set in. The cat may seem wobbly on its feet, unwilling or unable to walk. The cat may also lose interest in playing and grooming itself. Blindness can also occur if the disease reaches its final stages.  

Treatments for feline chronic kidney disease will depend on its cause. If it began with an infection, antibiotics might help. But many cases are, unfortunately, fatal. Treatments focus on supporting kidney function and making the cat comfortable.

Panosteitis

Panosteitis is a condition causing inflammation of a cat’s long leg bones. It’s more common in dogs but not unheard of in cats, largely affecting younger cats between 5 and 18 months.

Because the condition is triggered by rapid bone growth, larger breeds of cats, such as Maine coons, are most common. It more commonly affects the front legs, but the back legs can be adversely affected. Symptoms of panosteitis in cats include:

• Walking slowly or unsteadily
• Stiff gait
• Limping
• Lethargy
• Lack of appetite and weight loss
• Fever
• Depression

Though panosteitis is painful, it’s not dangerous. An underlying illness doesn’t cause it, and it isn’t fatal to the cat. Milder cases of panosteitis can last only a few days, while more severe episodes may last several months.

Because cats with panosteitis are in pain when they walk, they become reluctant to move. This can result in muscle atrophy over a long period of time, and physical therapy may be necessary to help the cat recover.

Bone Cancer

Several types of bone cancer can affect cats. The most common type, responsible for over 95% of cases, is osteosarcoma. It can occur in any bone in a cat’s body. Cats of any age can get bone cancer, but older cats are most at risk.

If a cat has bone cancer in its back leg, this will gradually affect its ability to walk. Lameness in one leg is the most obvious symptom, resulting in an awkward gait and reluctance to put weight on the leg.

Bone cancer in a cat’s spine or skull can also affect its movement. Cancer of the skull puts pressure on the brain, causing neurological symptoms such as seizures and wobbliness. You may also notice:

• A swelling or solid mass elsewhere on the body
• Loss of appetite
• Lethargy

Veterinarians can diagnose bone cancer using physical examinations and x-rays. The earlier a diagnosis is made, the better the chances of recovery.

Feline bone cancer can be fatal, but there are ways of treating it. If the tumor is in the leg, the bone/limb can be removed. Chemotherapy and radiotherapy can kill cancer cells, and painkillers can reduce discomfort.

Sudden Onset Back Leg Problems in Cats

Some back leg problems in cats come on rapidly rather than gradually. A sudden-onset back leg problem happens out of the blue and without prior warning. One minute the cat is fine, and the next, it’s struggling to walk.

There are many reasons why a cat’s back legs might suddenly stop working. The most common cause is injury, resulting from trauma to the legs, spine, or head. However, sudden-onset leg problems can be caused by infection, disease, stroke, blood clots, or toxicosis.

Physical Trauma

Cats can experience physical injury in a myriad of ways. Falls, misguided jumps, and getting stuck in small spaces can cause physical trauma.

Outdoor cats can be hit by cars, attacked by wild animals, or harmed by neighborhood dogs. Small children are prone to injuring cats by sitting on them, pulling their tails, or squeezing them too tightly, and cats can injure themselves through overexertion. Injuries that can affect a cat’s rear leg function include:

• Strain (pulled muscle)
• Sprain (stretching or tearing of the ligaments)
• Broken bone
• Dislocated joint
• Slipped disc in the spine

Flesh wounds, damaged claws, stuck thorns, and splinters can make a cat reluctant to put weight on its legs. Cats can even burn their paw pads by jumping onto a hot surface, such as a stovetop.

Some injuries heal naturally, while more serious trauma may need medical treatment. Broken bones, for example, often need to be set in a cast.

Bacterial Infection

There are many ways for bacteria to get into a cat’s body. For example, an open wound can become infected when bacteria get under the skin. Bacteria can also be transmitted from one cat to another or through a flea or tick bite.

Contaminated food and water can also harbor bacteria. According to the Journal of Veterinary Internal Medicine, secondary bacterial infections can develop after contracting a virus.

Infections in cats start mild but worsen. Symptoms will vary depending on the location of the infection. If left untreated, they can lead to organ damage or inflammation of the brain or spinal cord. This can result in sudden weakness of the legs, lethargy, and even paralysis.

Mild infections can clear up on their own. However, if the infection has progressed so much that it affects the cat’s motor control, your veterinarian will likely have to administer antibiotics through an IV drip.

Viral Disease

Feline viral diseases can affect the back legs, and normally, this happens because the virus affects the brain or spinal cord. Although the disease may gradually onset, the leg-related symptoms will come on quickly.

One of the most dangerous viruses is FCoV. Most cases eventually recover on their own. However, according to the Journal of Feline Medicine and Surgery, up to 10% of cases lead to FIP (Feline Infectious Peritonitis).

FIP has two forms: wet (affecting the chest) and dry (affecting the brain and eyes). Dry FIP can cause difficulty walking and paralysis. Its other symptoms include:

• Lack of appetite
• Weight loss
• Diarrhea
• Fever
• Salivation
• Loss of vision
• Jaundice

Feline leukemia virus (FeLV) can also cause limb weakness and lethargy. This condition has similar symptoms to FIP, as well as breathing difficulties and enlarged lymph nodes.

Blood Clot

Blood clots are most common in cats with heart disease or cancer, but they can occur randomly. About 3% of feline blood clots have no apparent cause.

A blood clot that forms in a vein or artery (thrombus) will prevent blood from flowing properly. If it forms in the pelvic end of the aorta, this is called a saddle thrombus. A cat with a saddle thrombus will experience decreased blood flow to the back legs.

The most obvious symptom is sudden weakness or paralysis in one or both rear limbs. Other warning signs include:

• Yowling and hiding (due to pain)
• Weak pulse
• Rapid breathing
• Hind legs that feel firm and are cool to the touch
• Bluish or purplish tint to the rear paw pads

A blood clot is a medical emergency and can be fatal if not treated immediately. The prognosis will depend on whether the clot was random or triggered by an underlying illness.

Stroke

A stroke occurs when part of the brain stops receiving blood. Blood transports oxygen to brain tissue, and without it, brain cells start to die. Blood clots or hemorrhages can cause strokes (burst blood vessels).

Strokes and mini-strokes (ischemia – temporary reduction of blood flow) aren’t as common in cats as in humans. They are most common in older cats (9+ years). Symptoms may include:

• Lack of balance, weakness, and wobbliness
• Struggling to walk, or walking round in a circle
• Legs appear to stop working correctly (especially on one side)
• Falling over
• Head tilt
• Muscle spasms and seizures

The symptoms of stroke in cats usually come on suddenly and are often fatal. According to the Annals of Neurology, even 30 minutes of halted blood flow to the brain can cause irreparable damage.

However, seeing a veterinarian in time can improve the chances of recovery. Various treatments are available, including oxygen therapy, seizure medications, and physical therapy.

Poisoning

In a state of toxicosis, cats can become wobbly and unsteady on their feet or even paralyzed. Other symptoms may include vomiting, diarrhea, breathing difficulties, twitching, and seizures.

Many human foods are toxic to cats. These include:

• Onions
• Garlic
• Chocolate
• Tea and coffee
• Grapes and raisins
• Milk and dairy products
• Artificial sweeteners
• Alcohol
• Raw eggs, fish, and meat

If your cat is allowed to go outside, it may come into contact with further poisons. Pesticides, rat poison, slug killer, and plants such as lilies can all be deadly to cats. Cats are also attracted to antifreeze because of its sweet taste, which can cause kidney failure.

Envenomation

Envenomation means the injection of a toxin into the body. In the U.S., the most common culprits of envenomation in cats are spiders and snakes. Venomous snakes include coral snakes and pit vipers, such as rattlesnakes. The most toxic spiders are brown recluses, black widows, and hobos. 

Cats that have access to the outdoors are most likely to be bitten. However, spiders and snakes can also make their way into houses, so indoor cats are not completely safe.  

Neurotoxic venom can cause muscle weakness and paralysis, which will worsen as the venom moves through the cat’s system. The bite wound can also be inflamed and painful, causing reluctance to put weight on the limb. Other symptoms may include:

• A bite mark that looks like two small holes
• Bleeding from the wound
• Swelling, redness, and bruising, especially in the affected limb
• Rapid heartbeat and breathing
• Lethargy
• Vomiting
• Excessive salivation

According to the Journal of Feline Medicine and Surgery, pit viper envenomation in cats has a 16-22% mortality rate.

How to Help a Cat with Weak Back Legs

A vet should see a cat with weak, wobbly, or stiff back legs. This is especially important if the symptoms have come on suddenly or are severe. As there are many causes of back leg problems in cats, getting a diagnosis is vital. Your vet may need to run a blood test or a scan, such as an x-ray.

The course of action will depend on what’s causing your cat’s movement problems. Treatments may include medication, surgery, or other interventions such as a cat wheelchair. Some illnesses, like arthritis, have no cure, but certain medications can reduce pain.

While waiting for a diagnosis, focus on making your cat feel as comfortable as possible. For example:

• If your cat’s bed is high up, move it to the floor
• Give your cat soft bedding and blankets to sit on
• Keep your cat’s food and water bowls at ground-level
• Implement short, gentle play sessions
• Discourage your cat from climbing and vigorous activity
• Use a low-sided litter tray
• Gently massage your cat’s legs

If your cat is overweight, putting it on a diet is beneficial. The less weight your cat has to carry around, the easier it will be to move.