You take good care of your dog's nails, making sure they're trimmed regularly and don't grow too long. If your dog suffers from certain autoimmune diseases, in which his immune system attacks its own tissues, none of that good care matters. Autoimmune diseases affecting the nail bed are relatively rare. If your dog does develop nail bed problems, you might want to take him to a veterinary dermatologist for diagnosis and treatment.
The autoimmune disease lupoid onychodystrophy doesn't appear gradually. An affected dog suddenly has several claws separating from the nail bed at the same time, generally on more than one foot. The claws either come off completely or hang on loosely. The base of the nail swells, possibly with a foul-smelling discharge emanating from it. Your dog's feet will hurt, so he'll probably be limping and licking the toes.
Lupoid onychodystrophy is more likely to affect certain breeds. These include the greyhound, German shepherd, Labrador retriever, schnauzer, Rottweiler, poodle, Rhodesian Ridgeback, Siberian husky, dachshund, Jack Russell terrier and cocker spaniel. While these breeds are predisposed to lupoid onychodystrophy, the condition can affect any dog.
Your dog's loose nails must be removed. Your vet will prescribe antibiotics for the nail bed infection, along with medication for pain. Steroids to suppress his immune system might be given for a specified period. Your vet might recommend dietary changes and supplements such as vitamin E and fish oil. It can take a long time -- several months -- before nails grow back. Your dog might need to remain on the special diet, supplements and certain medications for the rest of his life. Severely affected dogs might require permanent nail removal, especially if the nail bed is so badly damaged that nails will never grow back normally.
Types of pemphigus, an autoimmune condition, usually affects a dog's skin, but they can involve the nail beds. Pemphigus foliaceus can cause footpad issues, which also affect the nails. Pads crack and grow too long, with bacterial infections often occurring. Pemphigus erythematosus causes similar symptoms. Pemphigus vulgaris, the most serious of these immune disorders, rarely affects the feet. Pemphigus vegetans causes large pustules to form, but these occur most often on the skin. Along with temporary steroid therapy, your vet treats this disease with medications for the particular form of pemphigus.