Canine Callus Dermatitis & Pyoderma

Large breeds are prone to calluses.
Jupiterimages/ Images

A dog has a risk of acquiring pyoderma and dermatitis through calluses; this is called canine callus dermatitis, and it can lead to canine callus pyoderma. If your dog is spending a great deal of time biting and scratching at his elbows or above his ankles, an infection may be progressing. Consult your dog's veterinarian for a prompt diagnosis and treatment regimen.


Pyoderma is a bacterial infection of either the surface of the skin, or the superficial or deep layers. The infection is usually caused by the bacterium Staphylococcus intermedius, which naturally occurs on the skin, but a disturbance in the normal balance of bacteria results in an infection. If only the surface layers are affected, major problems are rare; but superficial and deep layer infection can cause significant discomfort for your dog. Pain, itching, swelling and hair loss surrounding affected hair follicles are often observed with bacterial pyoderma.

Callus Dermatitis

Dermatitis is a risk factor for developing canine pyoderma, since a dog scratching and biting at an affected area can create cracks in the skin that provide warm, moist and dark areas perfect for bacteria overgrowth. Large and giant breeds are at risk of developing calluses on their elbows and hocks, while some deep-chested breeds develop calluses on their chest. A callus normally protects the skin, but small cysts can exist around hair follicles where calluses exists, and -- as a dog repeatedly presses against the cysts -- the hair and bacteria can push into the callus, leading to pyoderma. Callus dermatitis is often red and irritated. As pyoderma of calluses progresses, the calluses may develop bumps, blackheads, holes or discharge. A foul odor may be present.


A vet will diagnose a skin infection by examining the papule's pus content on glass slides as well as by obtaining skin scrapings and biopsies. Cultures will determine the type of bacteria causing the infection. The veterinarian also observes the affected skin and calluses to determine clinical signs and symptoms of the infection. Underlying causes are diagnosed to help with treatment. Fleas, ticks, yeast and fungal infections can predispose the dog to callus dermatitis and pyoderma. Hormonal imbalances and hypothyroidism are also risk factors for infection.


Once the type of bacteria is determined, the vet puts the dog on antibiotics for two to six weeks and prescribes a medicated shampoo to relieve skin discomfort. Call your dog's veterinarian if you see no improvement after several days of treatment or if the conditions return after the full course of antibiotics. Use soft bedding and keep your dog at a healthy weight to reduce the amount of pressure placed on calluses to minimize bacteria being pushed into the skin. Underlying causes of the pyoderma and callus dermatitis must be treated.