How Do Cats Keep Their Claws So Sharp? The Surprising Science Behind Feline Scratching

Cats have sharp claws that play an important role in their daily lives. Their claws are crucial for climbing, hunting, grooming, and defending themselves. Keeping claws healthy and sharp is essential for a cat’s wellbeing. In this article, we’ll explore the anatomy of cat claws, how they function, and tips for keeping them in optimal condition.

Anatomy of Cat Claws

A cat’s claws are complex structures made up of bone, keratin, blood vessels, nerves, and muscles. They are attached to the distal phalanges, the last bone of each toe. Cats have a total of 18 toes, with 5 toes on each front paw and 4 toes on each back paw, and a claw emerges from each toe.

The main structural component of cat claws is keratin, the same protein that makes up human fingernails and hair. Keratin cells grow in layers, starting at the base of the claw where it emerges from the skin. New layers push older claw material outward, causing the claw to continuously grow. Claws are attached to the bone via the claw bed.

Inside each claw is the quick, which supplies blood to the claw. The quick contains soft tissues, blood vessels, and nerves. It’s analogous to the cuticle in human nails. The size of the quick determines the maximum length a cat’s claws can grow before they naturally shed the excess.

Cats can voluntarily extend and retract their claws thanks to muscles surrounding the claw sheath. When relaxed, the claws are retracted into the paw, keeping them sharp. Flexing the muscles within the toes causes the ligaments to squeeze the claw forward and protrude from the furry toe pads.

diagram of cat claw anatomy

Understanding the anatomy helps explain how cat claws grow, retract, and stay sharp enough to serve cats’ needs. Proper claw health requires keeping the outer keratin and inner quick in balance.

Using Claws

Cats rely on their claws for several important functions in their daily lives.

For climbing – Cats use their sharp claws to grip surfaces and climb trees, fences, furniture, and more. This allows them to access high vantage points for observing their surroundings, and escape routes if threatened.

For scratching – Scratching and clawing is a natural behavior for cats that allows them to stretch their bodies and mark their territory. The scratching motion also helps shed old layers from their claws.

For hunting – Cats rely on their sharp claws to catch, hold, and kill prey. Their claws give them an advantage when hunting small animals like mice, birds, and insects.

For defense – If threatened, cats will use their claws to defend themselves from predators. Their claws are weapons that provide protection.

How Claws Stay Sharp

Cat claws stay sharp due to the way they continuously grow and shed layers of keratin. A cat’s claw consists of a core made up of bone surrounded by layers of keratin, which is the same protein that makes up human fingernails and hair. The outermost layer of keratin is called the claw sheath.

As new keratin grows, it pushes the old keratin up and out, causing the layers to shed. With each old layer that peels away, a razor-sharp new claw tip is exposed underneath. This is why claws remain sharp even though cats use them frequently for scratching, climbing, hunting, etc. The old claw sheaths simply fall off, allowing the new sharp layers underneath to take over (RichellUSA).

Cats frequently scratch objects to help speed up this shedding process. The friction from scratching loosens the old outer sheaths so they can peel off more easily, revealing the new sharp claws underneath. This is why cats seem to stay sharpen their claws even though they are simply shedding dull outer layers to expose the sharp inner claw (Quora).

Scratching Behavior

cat scratching on post
Cats scratch for several reasons. One is to remove the old outer layer of their claws, called the claw sheath. Cat claws are made up of many layers of keratin, similar to human fingernails. As the outer layers get worn down or damaged, cats will scratch to peel away these old layers and reveal the new sharp claws underneath. This is why cat scratching is often described as a natural grooming or maintenance behavior for cats [1].

Another reason cats scratch is to mark their territory. Cats have scent glands in their paws and will leave both a visual mark and a scent mark when they scratch objects. This is a way for them to claim an area or object as their own. Outdoor cats may scratch tree trunks as territorial markings, while indoor cats will scratch furniture or scratching posts for the same reason [2].

Cats also scratch to help stretch their bodies and flex their feet and claws. Scratching stretches their leg, back, shoulder, and neck muscles. Cats like to scratch when they wake up from naps to get the blood flowing and work out stiffness. Providing appropriate scratching surfaces helps satisfy this physical need for cats.

Claw Care Tips

Proper claw care is essential for your cat’s health and happiness. Here are some tips for keeping your cat’s claws healthy:

Provide scratching posts. Cats have a natural instinct to scratch, so provide appropriate surfaces like scratching posts. Place them in areas your cat frequents and make sure they’re tall enough for your cat to fully stretch. Scratching posts made of sisal, cardboard, wood, and carpet work well.

Trim overgrown claws. Use cat-safe trimmers to clip the sharp tip off overgrown claws every 2-3 weeks. Make sure not to clip too far up into the pink quick, as this can cause pain and bleeding. Only trim a few claws per session until your cat is comfortable.

Check claws for damage. Regularly inspect your cat’s claws for signs of cracking, peeling, redness, or infection, which could indicate a health issue. See your vet if you notice anything unusual.

With proper claw care, your cat can enjoy scratching while preventing damage to household items. Provide appropriate outlets for this natural behavior and monitor their claws routinely.

Declawing Controversy

Declawing a cat is a controversial topic that involves the amputation of the last bone of each toe. Many veterinarians and animal welfare organizations strongly oppose declawing due to the painful nature of the procedure as well as the negative lifelong effects it can have on cats.

Declawing a cat involves amputating the last phalanx bone of each toe using either scalpel, guillotine clippers or laser surgery. This is an extremely painful procedure as the claw is closely adhered to bone in cats. According to the Humane Society of the United States, declawing can cause acute pain, infection, tissue necrosis, lameness and long-term complications such as back and joint pain.

cat paw after declawing surgery

Many experts say studies show that declawed cats are more likely to develop behavioral problems and stress-related illnesses. According to the BBC, declawed cats are often reluctant to use litter boxes because digging in litter can be painful after surgery. This can lead to inappropriate elimination outside the litter box. Declawed cats may also become more aggressive and prone to biting since they no longer have their primary means of defense.

Due to these concerns, declawing is illegal in many countries around the world. It is also banned in some cities in California and other US states. Many vets encourage cat owners to consider alternatives like regular nail trims or soft plastic caps that cover the claws.

Claw Health Issues

Like any other part of a cat’s body, their claws can be susceptible to various health problems. Some common claw health issues include:

Broken Claws – A cat’s claw may break or split while scratching or playing. Broken claws are very painful and prone to infection. Signs of a broken claw include limping, swollen toes, bleeding, and reluctance to walk or jump. Treatment usually involves clipping the broken part of the nail and prescribing antibiotics or anti-inflammatory medication. The claw will eventually grow back.

Infections – Bacteria can enter the nail bed through cracks or trauma and cause an infection called paronychia. This results in redness, swelling, and pus around the nail. Infections require antibiotics and sometimes surgical drainage. Prevent infections by trimming nails regularly and keeping scratching posts clean.

Tumors – Both malignant and benign tumors can occur in cat claws, paws, and nail beds. Squamous cell carcinoma is the most common nail tumor in cats. Signs include nail deformation, swelling, and lameness. Tumors should be surgically removed. Early detection improves the prognosis.[1]

It’s important to monitor a cat’s claws for any signs of injury, infection, or abnormalities. Seek veterinary care if you notice limping, swelling, bleeding, or any change in your cat’s nails or paws. Prompt treatment can prevent minor issues from becoming serious claw health problems.

When to See a Vet

In most cases, minor claw injuries can be treated at home. However, it’s important to contact your veterinarian if you notice any of the following signs:

veterinarian examining cat paw

  • Persistent lameness or limping after a claw injury
  • Swelling around the claw that does not go down
  • Bleeding from around the claw that does not stop

According to VCA Hospitals[1], persistent lameness after a claw injury could indicate a fractured bone or ligament damage, which requires veterinary attention. Swelling and bleeding are also causes for concern, as they could signal an infection or more serious injury to the nail bed.

In addition, WebMD advises[2] contacting your vet promptly if the nail is partly or fully torn off. Your vet will likely need to bandage the paw and may prescribe antibiotics or pain medication.

Veterinary assessment is especially important if the claw was damaged by catching or snagging on something. The intense tugging force could lead to other injuries in the paw area that are not immediately obvious.

In summary, it’s better to be safe than sorry when it comes to claw injuries. Persistent or worsening signs warrant a veterinary visit to properly assess and treat the paw.


In summary, a cat’s claws play an important role in allowing them to hunt, climb, defend themselves, and mark their territory. Cats use their claws by honing them on rough surfaces to keep them in peak condition. Scratching serves to remove old outer layers and expose the new sharp tips.[1] While declawing may seem like an easy solution to avoid damage, it can significantly impact a cat’s quality of life and ability to exhibit natural behaviors. With proper claw care, providing scratching posts, and trimming when needed, cat owners can maintain healthy, functional claws for their pets.

Overall, a cat’s sharp claws are essential tools for mobility, hunting, and defense. By understanding their critical role in feline health and wellbeing, cat owners can better provide for enrichment and care. Keeping claws functional, protected, and well-maintained will ensure your cat lives its very best life.

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