Lupoid onychodystrophy, sometimes called lupoid onychitis, is a disease that affects the toenails or claws of dogs. The disease usually affects multiple claws on all four paws. Toenails will split or crack easily; become brittle, thick, or deformed; and in some cases, toenails may fall off, leaving the nailbed (also called the quick) exposed. Nails will come out at such odd angles that they look misshapen. The pet may lick his toes and paws frequently or have trouble walking.

Gordon Setters and German Shepherd Dogs are the most common dog breeds that develop lupoid onychodystrophy. The disease usually starts between 2-6 years of age. Veterinary scientists are not exactly sure what causes it, but the disease appears to be immune-mediated, meaning that it is triggered by an overactive immune system. Scientists also believe lupoid onychodystrophy can be inherited from one or both of the dog’s parents.

Diagnosing Lupoid Onychodystrophy

Lupoid onychodystrophy only affects the toenails. Because of this, veterinarians may be able to presumptively diagnose the disease based on the history and symptoms. This means they don’t officially diagnose the condition but make an educated guess based on the exam, symptoms, and signs the dog is showing. If the veterinarian suspects lupoid onychodystrophy, they may start treatment to see if the toenails improve.

If a diagnosis isn’t clear, tests may be needed to rule out or cross other diseases of concern off the list of potential causes. Bacteria and yeast infections, ringworm, and occasionally cancer can cause similar symptoms. Useful tests may include a biopsy of the nailbed; culture of the affected claws to grow yeast, bacteria, or ringworm; or microscopic examination of nailbed cells, also known as cytology. X-rays may be needed as well to make sure the toe bones are healthy.

Treatment

Treating lupoid onychodystrophy is difficult because no single treatment has been proven to work effectively in every dog. It can also take 6-12 weeks before the toenails start to improve, and treatments are usually needed lifelong. Common treatments include a combination of fatty acids, vitamin E, niacinamide, tetracycline, pentoxifylline, and medications to suppress the immune system (e.g. cyclosporine, prednisone). In many cases, the combination of medications will need to be adjusted several times, usually after 4-8 weeks, before finding the treatments that work best for that dog.  

It is important to give all medications as prescribed by the veterinarian for the appropriate length of time, even if you do not feel they are working. It is also important to avoid the temptation to try and treat your pet yourself. While some of these medications can be bought over the counter, the dosages differ depending on the combination of medications used and some can cause issues if too much is given. Call your veterinarian if you are concerned about your pet’s current treatment plan or if you feel the medications are causing your pet discomfort.