SYMMETRICAL LUPOID ONYCHODYSTROPHY (SLO):
SLO is a disease which affects the dog's nails or claws, it typically involve multiple nails and may occur on more than one foot. It does not seem to be contagious and the age of onset is usually between 1 to 6 years. 'Symmetrical' indicates that more then one foot is involved, 'oncychomadesis' refers to the loss of the nail, and 'lupoid' is used to describe microscopic changes of affected nails.
The underlying etiology is unknown however it is thought to be immune mediated. The typical symptoms of SLO are nails that fall off, are soft, friable, or hollow. A secondary infection may be accompanied by a strong smell, nail splitting, pained, distorted or twisted nails, and lameness. After successful treatment the nails may continue to grow out deformed due to damage to the nail bed, this does not indicate a reoccurrence of SLO. The typical treatment is antibiotics and high doses of fatty acids over a period of several months to life depending on the form and severity of the infection.
(Information from Giant Schnauzers of America)