Claws Out: How Overgrowth of Keratin Leads to Cat Claw Problems
Claws Out: How Overgrowth of Keratin Leads to Cat Claw Problems

Claws Out: How Overgrowth of Keratin Leads to Cat Claw Problems

By Deborah Hansen

While some fear the feline claw as a dangerous weapon, others admire the beauty and functionality embedded at the base of the cat paw. The extension of the skeletal system allows cats to mark their territory, kill prey and gently get the attention of the ones they love.

When claws are healthy, they are a thing of beauty and awe. When claws have problems, felines can become very uncomfortable to the point their posture is effected, early arthritis sets in and a sedentary lifestyle becomes a habit.

The feline claw is an epidermal structure with a quick running through the middle. The claw is made up of an insoluble protein called keratin. As the keratin on the outside dies from being too far away from the blood supply, it becomes a sheath. (A sheath is a tissue structure that tightly wraps around another tissue structure.) The sheath covers the new growth of keratin that surrounds the blood supply.

Unlike in dogs, the outer layer of the cat’s claw (the dead keratin) sheds about every two to three months in a healthy house cat. This peeling off of the old sheath to make way for the new keratin occurs when the dead keratin is holding too tight for the new keratin to grow.


A unique benefit that felines have that is different from the keratin growth found in humans and other carnivores, is the ability to retract their nails. When relaxed, a feline’s claws are retracted or snugly enclosed in the paw by dorsal ligaments. Dorsal ligaments are elastic bands of tissue. When a feline is ready to extend the claws, the deep digital flexor muscle is used. Once the feline relaxes, the claws return to their embedded position in the paw.

In the grooming environment, overgrown claws are common. As the keratin growth continues, the sheath peels off in a healthy growth cycle. This natural process continues repeatedly. Since most of the cats that come in for grooming are house cats, with or without outside time, they are not naturally wearing down their nails. When the nails are not being worn down or clipped on a regular basis, we encounter cat clients with claws that are piercing the paw pad, or have spiraled around next to the toe. In these situations, the feline did not receive the needed assistance in keeping their claws at an appropriate length. The keratin grew out of control and now human intervention is needed.

There is another common claw condition that is often seen in the grooming environment. Sometimes, especially in older cats, the nail sheath is not shed. Instead of growing in length, like embedded claws grow, the nail continues to get thicker and thicker. When the nail is cut, the sheath breaks away and a healthy, slender nail is left in its place. Often, when this healthier nail is revealed, it is pointed and needs to be trimmed as well.

It can be very alarming the first time you encounter a thick sheath. Often times when your nail clippers cut the nail, the nail smashes then peels off. While it is more time consuming, it is best to peel off the old, thick covering, and if needed, clip the new slender growth underneath. If you are working on a difficult cat, you may prefer to have the client return in a week and finish the nail trim at that time.

Ingrown, curling and peeling nails are all issues related to keratin. There are other claw issues in cats that are not keratin related, including trauma, bacterial, fungal, yeast, mites, tumors, plus symptoms of other complex health issues. Any problems with the claws can cause a cat pain. Overgrowth of keratin over long periods of time can cause significant discomfort while walking, often leading to mobility issues. It is important that the overgrowth of keratin is resolved and the cat receives regular nail trims to prevent the problem from reoccurring. ✂

Deborah Hansen, CFMG, CFCG is the owner of a very successful feline exclusive, house call grooming business, Kitty’s Purrfect Spa. She is also the founder of “Deborah’s Programs”, a complete rebooking system to get all cats onto a regular grooming schedule, and owner and creator of Kitty’s Kopy Kats, a stationary store for anyone who grooms cats. Deborah is the creative talent behind Feline Artistic Creations and an author in multiple publications with worldwide distribution. She is also a Feline Specialist and Correspondent for the National Association of Professional Creative Groomers. She can be found at

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