cat back legs not working
Cat Health and Wellness

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

Mobility problems in cats are easy to spot. Cats with wobbly or weak hind legs will have trouble walking, climbing and jumping. Back leg stiffness is common in older cats, but it can also affect younger cats and kittens.

Osteoarthritis is the most common cause of cat back leg stiffness. This primarily occurs in cats aged 10+, and can be diagnosed with an x-ray. Diabetes, organ failure and neurological problems can also cause gradual weakening of a cat’s back legs. If your cat’s back legs suddenly stopped working, this may indicate a blood clot, infection, or stroke.

Cats can also develop weak and wobbly legs as a result of trauma, such as a fall. To determine the cause of your cat’s back leg problems, look for co-occurring symptoms. Monitor your cat’s behaviour closely, and report any concerns to a veterinarian.

Rear Leg Problems in Cats

Cats are good at concealing when they’re in pain. This is an evolutionary adaptation designed to prevent a sick cat from being noticed by predators. But when a cat has problems walking or putting weight on its back legs, it’s significantly harder to hide.

Weakness and stiffness can be down to bone, ligament or 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. Symptoms that you may notice 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

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

Older cats, aged 10+, are the most likely to experience such problems. However, you shouldn’t brush off rear leg weakness or stiffness as “old age”. Old age in itself is harmless, but it makes cats more prone to developing certain medical conditions. A veterinarian will most likely be able to help, either by curing the ailment or managing its symptoms.

Gradual onset hind leg problems in cats are often caused by milder illnesses such as arthritis. However, some culprits – such as brain tumors and kidney disease – can be fatal if untreated. So, if your cat is slowly becoming weaker on its back legs, the problem should be investigated.

Arthritis

Arthritis is otherwise known as osteoarthritis or degenerative joint disease. It’s characterized by inflammation and deterioration of the joints, which can make movement difficult. Arthritis is mostly seen in older cats, though it can affect young cats too.

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

Feline arthritis can be mild or more severe. Severe cases are rarer than mild ones, but arthritis can get worse with time. 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 due to pain
  • Changes in personality e.g. becoming more aggressive and snappy than usual
  • Signs of discomfort when being picked up, held, or brushed

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

Veterinarians diagnose arthritis using radiographs and physical exams. Although there is no cure for arthritis, the symptoms can be treated to make them more manageable. For example, weight loss can ease pressure on the joints, and pain medications can help.

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 is passed down from parent to kitten.

Maine coons, Persians, and Himalayan cats are more likely to experience hip dysplasia than others. Mixed-breed cats (mutts) are least likely to get it. Although the defect is present from birth, it’s often not noticed or diagnosed until later in life.

The early years of a cat’s life may be symptom-free. But over time, the ball grinding in the socket causes wear and tear on both bones. Eventually, the hip joint becomes loose. Symptoms of hip dysplasia in cats include:

  • Limping
  • Walking stiffly or awkwardly
  • Weakness in the back legs
  • Obvious discomfort when 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. If you have a purebred cat with weak, wobbly or stiff back legs, this may be the cause. It’s diagnosed through scans such as x-rays.

Anti-inflammatory drugs and pain medication can help cats with hip dysplasia. Severe cases may require a hip replacement operation, in which the hip joint is replaced with an artificial one.

Arthritis in cats hind legs

Muscle Wasting

Rear leg weakness and wobbliness can also be attributed to muscle damage. This can be triggered by direct muscle trauma (a fight or fall, for example), 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 a number of causes. For example:

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

Muscle loss in cats can be mild, moderate or severe. It should be diagnosed and treated as soon as possible. A lack of muscle can have negative effects on a cat’s health, such as depressing its immune system.

To diagnose muscle wasting, a veterinarian will assess your cat’s muscle condition score (MCS). This can be done by palpating (feeling) the cat’s muscles.

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

Neurological Issues

As well as bone and muscle damage, rear leg problems in cats can also be caused by neurological issues. In particular, damage to the brain’s motor cortex.

The motor cortex is the area of the brain responsible for voluntary movement. 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 come on gradually. For example:

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

Neurological issues in cats can be diagnosed using brain scans. Some illnesses (such as infections) can sometimes be cured completely. Others, such as malignant brain tumors, often prove 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 some body parts receive inadequate oxygen. 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, and 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 just through wear and tear on the heart muscle.

Heart disease can cause a gradual weakening of the back legs, if inadequate blood flow reaches them. 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 first listen to the cat’s heart with a stethoscope. Scans such as ultrasounds, echocardiograms and x-rays can confirm the diagnosis.

There is no outright cure for feline heart disease. However, there are medications that can help relax the heart muscle and slow it down. 

Feline Diabetes

Diabetes mellitus is a disease that can affect most animals. It’s caused by the underproduction of insulin, or the body responding incorrectly to it (insulin resistance). Around 1 in 230 cats will develop diabetes in their lifetime. It’s most common in obese cats, and older cats (7+ years).

The first signs of feline diabetes are often hard to spot. 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. It results in weakness, unsteady gait, and wobbly back legs. You may notice the cat has trouble jumping and climbing.

Fortunately, feline diabetes is manageable through a low-carbohydrate diet and regular administration of insulin. However, it can be life-threatening if it’s not treated. If your cat has 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. It’s most common in cats over 15 years of age, according to the Journal of Small Animal Practice.

It’s the job of the kidneys to filter the blood, and get rid of toxins. Without this important process happening, the cat is gradually poisoned.  A cat with chronic kidney failure will slowly become unwell over months or years.

Symptoms of kidney disease in cats start off 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 sets 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 may 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 is more common in dogs, but not unheard of in cats. It affects primarily younger cats, between 5 and 18 months, and is also called ‘growing pains’.

Because the condition is triggered by rapid bone growth, it’s most common in larger breeds, e.g. Maine coons. Panosteitis usually affects the back legs, but it can occur in the hind legs too. 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. It isn’t caused by any underlying illness, 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, it can make them reluctant to move. This can result in muscle atrophy over a long period of time. Physical therapy may be necessary to help the cat recover.

Bone Cancer

There are several types of bone cancer that can affect cats. The most common type, responsible for over 95% of cases, is called 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 (as with most cancers).

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. This results 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 somewhere on the cat’s 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 can be removed (or the entire limb). Chemotherapy and radiotherapy can also help kill cancer cells. Drugs can also be given to help reduce pain.

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 all at once, without prior warning. One minute the cat is fine, and the next it’s struggling to walk.

There are many different reasons why a cat’s back legs might suddenly stop working. The most common cause is injury. This can be a result of trauma to the legs, spine, or head. However, sudden onset leg problems in cats can also be caused by infection, disease, stroke, blood clot, or toxicosis.

Sudden-onset back leg problems in cats are often more serious than gradual ones. If your cat has abruptly lost the ability walk, balance, jump, or climb, take it to an emergency veterinarian. Delaying treatment can often make the problem worse.

Physical Trauma

Cats can experience physical trauma (injury) in myriad ways. The phrase “curiosity killed the cat” exists for a reason – it’s often their inquisitive nature that causes problems. Falls, misguided jumps, and getting stuck in small spaces can all cause physical trauma.

Outdoor cats can be hit by cars, attacked by wild animals or neighborhood dogs. Small children are prone to injuring cats by sitting on them, pulling their tails, or squeezing them too tightly. And just like us, 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 also 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, without intervention. More serious trauma may need medical treatment. Broken bones, for example, often need to be set in a cast. Your veterinarian may also prescribe pain medication to make your cat more comfortable while it recovers.

Bacterial Infection

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

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

Infections in cats start off mild. Symptoms will vary depending on the location of the infection. But if 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 paralysis.

Mild infections can sometimes clear up on their own. However, if the infection has progressed to the point of affecting the cat’s motor control, it may be serious. Your veterinarian will likely have to administer antibiotics through an IV drip.

cat back legs collapsing

Viral Disease

There are many feline viral diseases that can affect the back legs. Normally, this happens because the virus affects the brain or the spinal cord. Although the disease itself may have a gradual onset, the leg-related symptoms will come on quickly.

One of the most dangerous feline viruses is feline coronavirus. Most cases eventually get better 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 can have 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 weakness in the limbs and lethargy. This condition has similar symptoms to FIP, as well as breathing difficulties and enlarged lymph nodes.

Sadly, there are no cures available for FIP and FeLV. They are almost always fatal, though cats can sometimes live for months or years with the disease. Treatments can help relieve symptoms and make the cat more comfortable. There are also preventative vaccines, though these will not help a cat that’s already caught the virus.

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 is a medical emergency that occurs when part of the brain stops receiving blood. Blood transports oxygen to brain tissue, and without it, brain cells start to die. Strokes can be caused by blood clots or hemorrhages (burst blood vessels).

Strokes and mini-strokes (ischemia – temporary reduction of blood flow) aren’t as common as 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.  Unfortunately, they are often fatal. According to Annals of Neurology, even 30 minutes of halted blood flow to the brain can result in 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

Consuming a poisonous substance can have devastating effects on a cat’s internal organs. 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 foods that are safe for human consumption are toxic and deadly to cats. For example:

  • 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 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, and this can cause kidney failure.

Never try to induce vomiting if you suspect your cat has been poisoned. Instead, take it straight to an emergency veterinarian.

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 (e.g. rattlesnakes). The three 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 immune.  

Neurotoxic venom can cause muscle weakness and paralysis. This will get worse 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 which looks like two small holes (this may be too small to see)
  • 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. However, antivenoms are available which can help. 

How to Help a Cat with Weak Back Legs

A cat with weak, wobbly, or stiff back legs should be seen by a vet. This is especially important if the symptoms have come on suddenly, or are severe.

As there are so many potential causes of back leg problems in cats, getting a diagnosis is vital. Your veterinarian may be able to identify the problem in one appointment. They may, however, 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 there are medications that can help with the pain.

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

  • If your cat’s bed is high up (on a chair, shelf, or cat condo), 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 it will tolerate it

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