The Truth About Cats’ Thumbs. What’s the Reason Behind This Evolutionary Oddity?


Have you ever closely examined your cat’s paws and noticed they have something that resembles a thumb? That extra toe-like digit is technically called a dewclaw, but many cat owners refer to it as a thumb. While it may look like a mini thumb, it serves a different purpose than human thumbs and comes from a unique evolutionary history.

In this article, we’ll explore everything you need to know about cats’ “thumbs.” We’ll cover the technical name and definition, evolutionary origins, anatomy, usage, the declawing controversy, related health issues, appearances in pop culture, and more. You’ll gain a deeper understanding of this distinct physical feature of felines and why it exists.

Technical Name and Definition

The technical name for cat thumbs is prepollical claws. Prepollical claws are claws that are located on the innermost digit of an animal’s front paws, essentially functioning as opposable thumbs. In cats, these specialized claws are found on the inner surface of the paw, enabling cats to grasp and hold objects. Other mammals like pandas, ferrets, and moles also have prepollical claws.

The word “prepollex” refers to the vestigial first digit on the forelimb of tetrapods. Cats have retained an enlarged claw on this digit, allowing it to serve as a pseudo-thumb for grasping prey and climbing.

According to research, the prepollical claw in cats is composed of a bony core ensheathed with a keratinous cuticular claw sheath, similar to other digits. However, it is more curved and narrower than the regular claws on the other toes [1].

Evolutionary Origins

The prepollical claws found on cats, also known as dewclaws, originally evolved to aid felines while climbing and hunting prey. Dewclaws act as a thumb of sorts, providing an extra gripping digit on the legs. They likely first developed in wild cats as an evolutionary advantage for grasping branches and catching prey.

According to Wikipedia, the dewclaw’s name refers to its alleged tendency to brush dew away from grass as felines walked. The dewclaws on cats are located on the inside of the front legs, similarly to how human thumbs are positioned compared to other fingers.

Over time, as cats became domesticated and no longer needed to climb trees to hunt prey, the dewclaws remained but became less functional. They still aid cats in grasping and scratching. However, since dewclaws do not touch the ground while cats walk, they are not constantly worn down and can sometimes grow long if not trimmed.


A cat’s prepollical claw, sometimes called a dewclaw, is located on the inner side of the front leg, above the paw. It is smaller than the other claws and sits higher up on the leg. Unlike other cat claws, the prepollical claw does not touch the ground when the cat walks (The Anatomy of A Cat Claw [2023]).

The prepollical claw contains a bone, ligaments, tendons, nerves, blood vessels, and corium, which produces new claw material. The bone extends from the leg bone and is surrounded by a corium that grows the claw and anchors it to the toe. The claw grows continuously and sheds layers as it wears down from use. The quick, located in the center of the claw, contains nerves and blood vessels that supply nutrients for growth (The Anatomy of A Cat Claw [2023]).

In contrast to the other claws on a cat’s paw, the prepollical claw does not retract fully. It protrudes from the fur even when retracted. The other claws withdraw into the toe pads when not in use, allowing for silent stalking. The prepollical claw stays slightly extended at all times (Cat claw anatomy | Warriors Amino).

While other claws are shaped like hooks to grip prey and scratch, the shape of the prepollical claw is flatter and straighter. Its purpose is likely for grooming and scratching hard-to-reach spots (Cat claw anatomy | Warriors Amino).


Cats use their extra toes and “thumbs” in a variety of ways that help them in their daily activities.

Climbing – The extra gripping power from additional toes assists cats in climbing trees, fences, and other surfaces. Their dexterous “thumbs” help grasp branches and provide stability.

Scratching – When cats scratch objects for grooming and marking, the extra “fingers” allow them to get better leverage and dig in more effectively.

Hunting – Polydactyl cats can be better hunters, as their extra toes aid in catching prey and provide better balance/traction when pouncing and running.

Grasping – The thumb-like digits give cats more dexterity in picking up objects, catching treats, and manipulating toys.

Balance – The wider paws improve cats’ equilibrium and prevent slipping on slick or uneven surfaces.

In short, polydactyl cats put their extra thumbs and toes to good use in navigating their environment. The additional digits give them physical advantages over normal cats in many day-to-day activities.

Declawing Controversy

Declawing cats is a controversial procedure that involves amputating the last bone of each toe. This removes the claw and prevents regrowth. It was once commonly performed in North America to prevent cats from damaging furniture and belongings with their claws. However, declawing has faced increasing backlash in recent years over ethical concerns.

Opponents argue declawing is inhumane, painful, and permanently disables a cat’s natural behaviors like stretching and scratching. They say it can cause long-term medical issues such as chronic pain, arthritis, and litter box avoidance. Many vets now refuse to perform the surgery, with veterinary associations like the American Veterinary Medical Association opposing routine declawing. Critics view declawing as barbaric mutilation done primarily for human convenience without concern for the cat’s welfare. Some jurisdictions have banned or limited the practice.

Proponents say declawing protects furniture and prevents cats from being abandoned or euthanized when owners face destructive clawing issues. They argue it is a safe procedure when done properly under anesthesia, with some vets still recommending it as a last resort. Supporters say declawing should remain a choice for owners if alternatives like trimming nails or scratching posts fail. They view a ban as limiting options for struggling cat guardians.

There is intense debate around declawing as a humane and ethical choice. More vets are promoting alternatives, but the surgery remains legal in most areas despite growing calls for bans. Owners must weigh declawing’s risks and critics’ concerns against its benefits in protecting belongings. It is a complex issue pitting convenience against cats’ natural behaviors and welfare.


Cats have unique thumbprints on their paws, much like human fingerprints. A cat’s thumbprint comes from small ridges and loops in their skin, which create distinctive patterns. These thumbprints are present on a cat’s paw pads, including the large pad on their hind feet. Cat owners can often identify which paw print belongs to which cat based on these distinctive thumbprints. Some owners will even ink their cat’s paws and press them onto paper to keep a copy of the prints. Cat thumbprints can make for cute fingerprints arts and crafts. For example, you can use print cat noses and whiskers onto their paw prints to make adorable cat fingerprint art. Cat paw prints with visible thumbprints are another way that cats have their own individual markings, like a human fingerprint.


Health Issues

While polydactyl cats generally do not experience major health problems due to their extra toes, there are some potential medical issues to be aware of.

One concern is that extra toes may be poorly attached and more prone to injury. A cat’s paws already undergo a lot of wear and tear from normal activity like scratching, climbing, and exploring. Additional toes can be vulnerable to catching on carpet, tearing claws, getting stepped on, or other trauma. If an injury occurs, it is important to promptly clean and bandage the wound to prevent infection.

In rare cases, kittens may be born with a deformity like radial hypoplasia where the extra toes are fused together. This abnormality can limit mobility and may require surgical correction. Polydactyl cats can also experience ingrown claws, arthritis, and other age-related paw issues over time. Close monitoring by a veterinarian and keeping nails trimmed can help prevent complications.

While individual cats experience varying degrees of problems, most polydactyl felines live full, healthy lives. Preventative care and prompt treatment help mitigate risks. Overall, polydactylism may pose some health considerations, but does not prevent cats from enjoying mobility, activity, and a good quality of life.

In Pop Culture

Cat thumbs have become a popular subject in pop culture, appearing in movies, cartoons, memes, and more. People seem fascinated by cat thumbs and their unique appearance. Some examples include:

The meme of the “crying cat giving a thumbs up” has spread widely online, often used to indicate something is bittersweet but acceptable. The awkwardly placed cat thumb contrasts with the crying face for comedic effect (“Crying Cat Thumbs Up Meme” Poster for Sale by cnon626).

In cartoons and movies, animators will sometimes anthropomorphize cats by giving them opposable, thumb-like digits to allow them to grasp objects. For instance, the cat characters in Tim Burton’s Alice in Wonderland film are able to brandish swords with their thumb-like appendages.

Some social media users have had fun posing their own cats’ thumbs in unusual positions, playing with the strange flexibility and versatility of feline pollexes. The thumbs’ prominent appearance and useful grasping ability fascinates cat lovers.

Overall, cat thumbs have become an Internet phenomenon, appearing across media in amusing and endearing ways. Their prominence shows people’s endless fascination with cats’ unique anatomy.


In summary, cat thumbs are an interesting anatomical feature resulting from genetic mutations and evolution. While polydactyl cats have extra toes and thumb-like appendages, they serve little functional purpose for cats in the modern world. Some cat owners find thumbs endearing, but others worry about associated health problems. Ultimately, cat thumbs are amostly harmless quirk resulting from the feline genome’s tendencies to duplicate certain genes. While cat thumbs may seem unusual, they provide a fascinating glimpse into how evolution and genetics can produce anatomical variations, even in domesticated animals.

Cat thumbs are neither good nor bad inherently – they are simply a biological difference. With proper care and veterinary oversight, polydactyl cats can live long and healthy lives as beloved pets. Their extra toes neither help nor hinder their ability to be happy, playful animals. Perhaps the existence of cat thumbs serves as a reminder that differences in anatomy do not have to limit ability or potential. Just as cats with thumbs are still excellent mousers and companions, people with physical differences can excel and thrive as well. In the end, cat thumbs are an endearing example of nature’s creativity.

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