Cat Rear Leg Weakness: Causes and What to Do

Cats are nimble creatures who should navigate the world with sophistication and ease. If your cat is suddenly weak or stumbling or has lost power in their back legs, you’ll notice something is amiss right away.

Rear leg weakness can be alarming for pets and owners alike and should always be taken seriously. Your vet will aim to identify the cause as quickly as possible, in an attempt to reverse the symptoms and to treat any underlying medical issue.

What Does Rear Leg Weakness in Cats Mean?

Weakness in the limbs can present as a cat walking with a sunken gait, being wobbly or shaky, or unable to use their legs at all.

Although some medical issues may make a cat weak all over, there are a number of conditions that will affect just the rear legs.

What Are the Common Causes of Rear Leg Weakness in Cats?

It is not always easy to know why your cat’s legs have suddenly gone weak, and several possible causes should be considered.

Spinal Cord Injuries or Trauma

The spinal cord supplies the lower limbs with electrical nerve signals, allowing communication between your cat’s brain and their legs. Anything that interferes with the spinal cord's function can lead to weakness or paralysis of the limbs.

When the hindlimbs alone are affected, this generally means that the spinal cord compression is somewhere beyond the neck, or the ‘cervical’ region.

Injury to the spinal cord can be secondary to a fall from a height or a car accident, but can also occur due to non-traumatic conditions such as intervertebral disc disease (IVDD), when the cat’s vertebrae compress the spinal cord. IVDD is more frequently seen in dogs, and cases are much rarer in cats.

Blood Clots and Sudden Paralysis

For many vets, blood clots will be at the forefront of their minds when a cat presents with hindlimb weakness.

The saddle thrombus (also called an aortic thromboembolism) is a life-threatening emergency that can cause sudden hindlimb weakness or paralysis and severe pain.

Although the prognosis for this condition has improved in recent years, over half of cats will not pull through the event. Those who do survive usually have underlying heart disease and are at high risk for future blood clots.

Arthritis and Degenerative Joint Disease

While arthritis will be a consideration, these cats have usually been showing subtle signs for some time before getting to the point of obvious weakness or collapse.

This will typically be an older cat who has lost muscle in their hind limbs and has been slowing down and struggling to jump in recent months.

Cat Bites

While it may seem strange to include cat bites in the list, they are an incredibly common cause of weakness or lameness of the backend. Cats are often bitten on the rump or the top of the tail as they run away from a fight, causing intense pain in those areas.

As well as pain in the affected area, you may be able to spot the puncture mark, swelling or scabs associated with the cat bite.

Toxin Exposure or Poisoning

Of course, toxicity must be considered too. An overdose of parasite prevention medication is a common cause of cats presenting to the emergency room with wobbly walking and other neurological signs.

What Are the Signs of Rear Leg Weakness in Cats?

A cat with weakness in their back limbs may be reluctant to move about and might walk as if drunk or lose their balance.

Difficulty Walking or Dragging the Back Legs

Those who are not so badly affected might be able to walk on all four paws, but you may notice the paw drags on occasion or the gait seems a bit ‘off’.

Some cats are so severely affected that they drag their hind legs along with their front legs, leaving the hind limbs completely immobile.

Pain, Vocalisation, or Behaviour Changes

Many cats, they will be in discomfort. This can mean they do not want you near them and that they become aggressive.

Other common symptoms of pain in cats include:

• Howling
• Dilated pupils
• Panting
• Agitation
• Drooling
• Refusal of all food
• Shaking

Cold or Unresponsive Back Paws

The back paw pads may feel cold to the touch, particularly if a blood clot is affecting the local blood supply.

As well as feeling cold, they can take on a blue or pale hue. The lack of blood flow causes low oxygen levels, leading to cyanosis.

When is Rear Leg Weakness in Cats an Emergency?

Most of the time, if a cat develops weakness or paralysis of the back legs, it's an emergency.

Sudden Paralysis or Inability to Stand

A cat who struggles to stand or who has lost the ability to walk is always one that needs to be seen in the emergency clinic right away.

Severe Pain or Distress

Of course, any indication that the cat is experiencing intense pain is reason to have them assessed at the local emergency vet right away.

Having them seen is not only so immediate pain relief can be provided, but also because some of the conditions that can cause severe pain require prompt therapy in order to achieve a good outcome.

Changes in Breathing or Collapse

Altered breathing is always a big red flag. Signs such as panting or shallow breathing can indicate stress or a fever, but can also occur with heart disease or hypoxia (low oxygen levels).

Collapse can be seen after trauma or toxicities, or in cases of heart failure or severe anaemia. Given the range of serious conditions that could be at play, emergency care is always indicated.

What Should You Do if Your Cat’s Back Legs Suddenly Become Weak?

If you are concerned that your cat seems weak, contact your vet right away. Ensure your cat cannot escape the home, and try to limit their movement as much as possible.

How to Safely Handle and Transport Your Cat

Be aware that your pet may be fractious and difficult to handle. You might need to use thick gloves and a towel to scoop them into their cat carrier. This is best done in a small room (such as a bathroom) to make it easier to gently secure your pet.

When Should You Contact an Emergency Vet?

Contact the emergency vet right away, so they can prepare for your arrival. They will ask you to come in as soon as you can.

How Do Veterinarians Diagnose Rear Leg Weakness in Cats?

As soon as you arrive at the clinic, the veterinary team will begin stabilising your cat. At the same time, they will be collecting any relevant medical history from you.

Physical and Neurological Examination

Your vet will quickly assess your pet, checking for any signs of injury, watching how they move, and measuring their heart and breathing rate. They will be listening out for any heart murmur and feeling if the pulse is synchronous with the heartbeat.

In addition to a typical physical exam, the vet should perform a neurological exam to assess the central nervous system for signs of dysfunction, such as reduced limb sensitivity or an absent pain response.

Blood Tests and Diagnostic Imaging

Further tests will likely be conducted to better understand why this is happening.

Blood tests are useful for detecting signs of infection or inflammation, assessing organ function, and screening for diabetes.

Imaging of the spine, pelvis and back legs will frequently be undertaken, checking for any evidence of trauma or lesions like abscesses or broken bones. A quick X-ray can be very useful in an emergency setting, while CT or MRI scans provide more in-depth detail.

Additional Tests for Underlying Conditions

Further tests include blood pressure measurement, an echocardiogram or a CSF tap.

Your vet will determine which tests are most appropriate for your cat, as this will vary depending on your finances, the cat's age, and presenting symptoms.

What Treatments Are Available for Rear Leg Weakness in Cats?

The emergency vet will tailor your pet’s therapy to the cause of their symptoms. However, pain relief is often needed in all cases.

Emergency Stabilisation and Pain Management

The priority will always be to ensure that your cat is stable, and if they are in shock or hypoxic, this will be addressed urgently. This may include providing oxygen and intravenous fluids.

Strong pain relief will be given, usually intravenously. This may be a combination of medicines such as non-steroidal anti-inflammatories and opioids like methadone and fentanyl.

Medications and Further Management

Some cats will need specific medicines, such as anticoagulants, antibiotics, or antidotes to toxins. These medicines are initially given in the hospital under close supervision to monitor the cat's response.

Surgery in Severe Cases

Surgical therapy will be recommended for a small percentage. This may be the case, for example, for a cat who has fractured their spine or who is experiencing IVDD.

Can Cats Recover From Rear Leg Weakness?

The prognosis is variable and depends very much on the cat and the reason they’ve developed these signs.

Factors That Influence Recovery

Factors to consider include the cause of the weakness, the cat's age, and the duration of the symptoms.

The severity of the lesion must also be considered. A cat that has complete paralysis and a lack of any pain response will generally carry a poor prognosis.

Get Emergency Vet Care for Your Cat

Contact us if you require emergency vet care for your cat and are concerned that they may be experiencing pain or weakness in their back legs.

Cat Rear Leg Weakness FAQs

Why Are My Cat’s Back Legs Suddenly Weak?

Sudden weakness can have a number of causes, ranging from a cat bite on the rump or a muscle strain to more serious issues like a blood clot affecting the circulation.

Is Rear Leg Weakness in Cats an Emergency?

In most cases, this is an emergency, as it can indicate a problem with the circulation or nervous system.

Can a Cat Recover From Paralysis in the Back Legs?

Yes, recovery is possible in some cats. They have the best chance when assessed and treated promptly by a vet.

Why Are My Cat’s Back Legs Cold and Not Moving?

If you notice the paw pads are cold or blue, it can indicate reduced circulation, often due to a blood clot.