Like other large breeds, Great Danes tend to develop leg calluses. They develop because of "repeated trauma" that usually means simply that the dog constantly lies down on hard surfaces. Because he's so heavy, a Great Dane can develop these rough patches that don't appear on smaller dogs.
Calluses typically develop on the Dane's paws, elbows and parts of his legs and body relative to his favorite sleeping position. The Dane's weight on these bony areas obstructs blood flow, so cells die off and protective calluses develop. These pressure sores are unsightly but not particularly harmful by themselves. However, they can turn into hygromas -- fluid-filled sacs -- or become infected. Both conditions require veterinary treatment and can become serious problems without medical intervention. Great Danes can develop calluses from puppyhood on.
Your Dane's calluses develop into hygromas. These fluid sacs on pressure points and areas with prominent bone don't initially cause pain, but over time hygromas can abscess or ulcerate. The Merck Manual for Pet Health warns that "masses of inflamed tissue with sandlike deposits" are possible. Because inflamed and infected hygromas cause pain, your Dane has trouble finding an easy position for sleeping. Abscessed hygromas are particularly painful; the resulting infections can come to a head and open elsewhere on the leg.
Your vet can aspirate a small hygroma with a fine needle or simply lance it. Your dog might need a protective bandage for a while but should be fine. Larger or chronic hygromas require surgical drainage and flushing, with a drain left in place after the procedure for fluid removal. The Merck Veterinary Manual says small lesions are treatable with laser therapy but badly ulcerated lesions might require complete removal and skin grafting.
The best way to prevent calluses and subsequent hygroma is by providing your Dane appropriate bedding. He might love to snooze out on the hard floor, but avoid letting him do that. One option is to provide large, comfortable dog beds in various rooms so that wherever your big guy decides to lay his head in your house, he's got a soft place to sleep. Allowing your Dane on sofas and large chairs is another alternative. If your Dane develops calluses, put moisturizing cream on them to soften the skin.
Jane Meggitt has been a writer for more than 20 years. In addition to reporting for a major newspaper chain, she has been published in "Horse News," "Suburban Classic," "Hoof Beats," "Equine Journal" and other publications. She has a Bachelor of Arts in English from New York University and an Associate of Arts from the American Academy of Dramatics Arts, New York City.