Nailing It

VET ADVICE

Nailing It

By Merry Fitzgerald DVM

Why are my dog’s toenails falling off?

There are several reasons for poor nail quality in dogs, ranging from lack of proper nail maintenance to the food they eat to trauma or serious medical conditions. If your dog’s toenails are cracking or breaking frequently, the first thing to consider is the routine care of the nails. Toenails should be regularly kept at a reasonable length and not allowed to grow over into the pads of the toes.

Nutrition is another important factor in toenail health. Hair and nails are composed of keratin, which is primarily protein. This protein is acquired through the nutrients in the food dogs eat. One possible reason that your dog’s nails are too brittle is that there is a nutritional deficiency.

If you are feeding your dog a high-quality commercial diet, then it may be less of a problem with the diet and more of a problem with your dog properly absorbing the nutrients during the digestion process. While ingredients are important in developing diets, it is nutrients that are essential for your dog’s health. Nutrients can come from many different ingredient sources. Developing wholesome, high-quality diets is a science and should be left to the experts in that field. If your dog is being fed a proper diet and having trouble absorbing the nutrients properly, speak to your veterinarian to see if additional vitamin, mineral or protein supplementation is needed.

In some dogs, breaking nails may have more to do with trauma, as is often the case with Sighthounds. These breeds of dogs are fast runners and have very little cushion to protect the nails against concussive forces.

What medical conditions would cause the toenails to break off?

Medical conditions that can cause damage to the nails include vasculitis (inflammation in the blood vessels leading to reduced blood flow to the area), autoimmune diseases (pemphigus, lupus), allergies, ringworm, bacterial infections, hormonal diseases, parasites, viruses or inherited disorders of toenail keratin formation. Treating the primary disease is necessary to prevent further breaking and loss of toenails.

It may be difficult to get to the root of the cause. Your veterinarian will start with some basic diagnostics to rule out infectious causes first. If there is no infection and your dog is only mildly affected, your veterinarian will recommend changes to the diet, adding vitamins and minerals, and supplementation with essential fatty acids.

Response to treatment may be slow. Toenails are slow to regrow. If there is not significant improvement after three months of supplementation, it is time to consider other causes of your dog’s brittle nails. This involves running some blood tests or even biopsies to determine the cause.

What is systemic lupoid onychodystrophy?

Systemic lupoid onychodystrophy (SLO) is a disease that affects the toenails of dogs. The disease usually affects multiple claws on all four paws. The toenails split or crack easily. They become thickened, brittle or deformed. In some cases, the toenails may fall off, leaving the nailbed (also called the quick) exposed.

SLO usually starts between two to six years of age. Gordon Setters, Rottweilers and German Shepherd Dogs seem especially prone to developing SLO. The cause is not clear, but the disease appears to be immune-mediated, meaning that it is triggered by an overactive immune system. SLO is also believed to be an inherited condition from one or both of the dog’s parents.

Typically, the first sign of SLO is licking of the nails or lameness. The claws elevate from the nail bed, and the nail will fall off. Over a relatively short period of time, all nails on all paws are affected to some degree. When the nails regrow, they will be misshapen, dry, brittle and crumbly. Bleeding may occur beneath a retained nail. Secondary bacterial infections can occur as well.

How is SLO diagnosed?

SLO only affects the toenails. Because of this, veterinarians may be able to presumptively diagnose the disease based on the history and symptoms. They may start treatment to see if the toenails improve. If bacterial or yeast infections are present, these are treated first.

If a diagnosis is not clear, tests will be needed to confirm SLO. These tests include a biopsy of the nailbed and radiographs of the paws. The X-rays are taken to ensure the underlying bone is healthy and no evidence of cancer is seen. Bacterial and fungal cultures may also be recommended.

The best samples for biopsy are obtained by a P3 digit amputation. This involves removal of the end segment of the toe with the nail bed. The presence of an inflammatory process involving lymphocytes, plasma and basal cells and loss of pigment on the surface of the claw bed skin confirms a diagnosis of SLO.

What is the treatment for SLO?

Treating SLO is difficult because no single treatment has been proven to be effective in every case. It can also take six to 12 weeks before the toenails start to improve, and therapy is usually required for the life of the dog. If treatment is discontinued, the dog will have a relapse.

Antibiotics such as tetracycline or doxycycline with niacinamide are one treatment option. Supplemental omega 3 and omega 6 fatty acids are usually given to all cases of SLO. Biotin may be given orally with meals to strengthen nails.

Pentoxifylline is a drug that suppresses inflammatory reactions. It is used in addition to other drugs with variable results. Treatments with immunosuppressive drugs, such as steroids, azathioprine or cyclosporine, are prescribed in non-responsive cases.

More aggressive treatment for severe or recurrent cases of SLO includes onychectomy, which is the surgical removal of the toe tip. This procedure is often done with a laser or scalpel blade. The surgery is not commonly done unless there is significant unmanageable pain and deformity of the nail bed.

Owners need to practice diligent cleansing of the paws. It is beneficial to keep your dog’s paws and toes clean and dry. Medicated wipes can be used after walks outdoors. Diets enhanced with fatty acids are utilized when dogs are reluctant to take oral fatty-acid supplements.

What is the prognosis for dogs affected with SLO?

The overall prognosis once SLO is treated is good, but nails may continue to break and remain deformed. It can take three to four months to see improvement with successful therapy.

It is important to give all medications and supplements as prescribed by your veterinarian. Do not discontinue any without their approval, even if you believe it is not helping, because this can trigger a relapse.

Frequent nail trims are important and should be done every one to two weeks for the rest of your dog’s life. In some cases, your veterinarian may reduce the doses on the medications after six months of successful treatment, but in most cases, the medication is needed for life.