Structure and Function of the Claw and Footpad in Dogs

What Are the Claw and Footpad?

Claws are appendages at the extremities of the digits of dogs. The footpad is the tough spongy pads of thick skin beneath each foot.

Where Are the Claw and Footpad Located?

The toenail, or claw, emerges from the end of each toe. The foot also has cushiony pads for each toe and two larger pads farther up the paw.

What Is the General Structure of the Claw and Footpad?

The skin of the footpad is usually heavily pigmented and is the toughest region of canine skin. The surface of the pads is rough in dogs. Dogs' toenails have a blood supply or quick, but the end of the nails are dead tissue. The grow much like human fingernails and must be kept trimmed to avoid trauma.

What Are the Functions of the Claw and Footpad?

Dogs perspire through their pads.

Pads provide both traction and shock absorption; thick pads absorb more shock and increase endurance, while rough pads allow for better traction for quick turns and effective sprinting. Dogs have scent glands on the bottoms of their feet that allow them leave a mark that can be seen and sensed by other animals.

A dog's claws are fairly strong. They help the dog to run and maneuver, to dig and they do offer some protection. As would be expected, they help to provide stability to the feet.

What Are the Common Diseases of the Claw and Footpad?

Digital hyperkeratosis is increased thickness of the keratinized epidermis of footpads in dogs and rarely in cats. May be in response to trauma or associated with distemper. Often, the hard, cracked pads appear to have "keratin feathers" around their edges. A veterinarian can diagnose this ailment by analyzing a section of pad tissue.

Pemphigus is an auto-immune disease of the skin in which the immune system goes haywire and mistakes skin cells for enemy invaders. In the most common type of pemphigus, pus-filled sores – which eventually break and form crusts – develop on the foot pads, bridge of the nose and ears.

Zinc-responsive dermatosis is a breed-related form of dermatosis that occurs in Siberian huskies and several other Arctic breeds. It may also occur in puppies of any breed if their diet is deficient in zinc or absorption is impaired by excessive supplementation of calcium. This causes scaling and crusting, especially over pressure points and footpads. Breeds reported to have this disease are Ggreat Danes, Dobermans, beagles, German shepherds, and pPoodles.

Onychomycosis is fungal disease of the claws in which the claws become misshapen, discolored, thickened and friable.

Onychogryphosis is abnormal hypertrophy and curving of the claws.

What Types of Diagnostic Tests Are Used to Evaluate the Claw and Footpad?

Skin scrapings

X-rays,

Fungal cultures

Biopsy