Onychogryphosis in Dogs

Dogs have claws, also referred to as toenails, that are at the end of each of their toes. The claws have a blood supply, although the end of each nail is dead tissue. Like the fingernails of humans, claws grow and must be kept trimmed.

Fairly strong, the claws help the dog run, move around and dig; they also offer protection and help provide foot stability. Diseases can occur in your dog’s claws; one of which, onychogryphosis, is when there is abnormal, excessive development and curving of your dog’s claws.

Also called ram’s horn nails due to its appearance, onychogryphosis is abnormal excessive development and curving of the claws.

Should your dog have developed onychogryphosis, you will notice that his claw or claws have grown more than is typical as well as become curved. Other symptoms will depend on what condition is causing the onychogryphosis in your dog. Should the condition be idiopathic, your dog may not show other symptoms. If he is experiencing leishmaniasis, for example, you may observe hair loss, skin lesions, epistaxis, anemia, wasting, swelling of the limbs and joints, lameness, renal failure, ocular lesions and diarrhea. If he is experiencing pemphigus vulgaris or pemphigus foliaceus, you may observe pustules that progress to significant crusting. The nose of your dog will likely be impacted and can become discolored as a result of loss of pigmentation. Your dog will develop a severe, persistent itch. 

• Excessive growth of claws
• Curvature of claws

Types 

Another condition that can impact the claws of your dog is onychomycosis. This condition is a fungal disease of the claws that results in the misshapen, discolored and thickened claws. Onychogryphosis can be the result of different conditions as described below, or can be idiopathic.

Onychogryphosis can be a symptom of a primary condition or may be idiopathic. For example, it can result from one of the following:

• Leishmaniasis - An infection with protozoan parasites
• Pemphigus vulgaris and pemphigus foliaceus - An auto-immune disease that impacts your dog’s skin and mucous membranes, resulting in his skin falling apart due to the erosion of the mechanism keeping skin cells attached
• Idiopathic onychogryphosis - Typically impacts one digit and is diagnosed as idiopathic after other possible causes have been eliminated

Should you notice that there is a claw or claws of your dog that appears to be growing abnormally and curving, or any other symptoms of a condition with their paw or claw, you will want to contact your veterinarian and schedule an examination of your dog. Upon arriving at the veterinarian’s office, you will be asked about what symptoms you have observed in your dog and when you first noticed them. Your veterinarian will conduct a physical examination of your dog, paying careful attention to his claws. 

Depending up what you veterinarian observes when examining your dog, he will consider testing your dog to see if he is experiencing a primary condition that is resulting in his having onychogryphosis. Skin biopsies may be conducted around the claw or of lesions in the different areas, along with diagnostic antibody tests. Upon obtaining the results of the biopsy and/or antibody test, your veterinarian will contact you to let you know whether your dog is experiencing onychogryphosis and what is causing it to occur. If all possible causes have been ruled out, your veterinarian will consider the condition to be idiopathic.

The treatment that your veterinarian proposes will be dependent upon the condition that is causing your dog to experience onychogrphosis. For example, should your dog be diagnosed with Pemphigus vulgaris or pemphigus foliaceus the goal of his treatment will be to stop the immune system’s destructive response. His treatment will involve slowing down the immune system and protecting him from the infection that could occur when his immune system has slowed down. Oral corticosteroids or and/or other immune suppressants will be required for treatment. 

In the case of a leishmaniasis diagnosis, your veterinarian may recommend anti-leishmanial drugs like pentavalent antimonials and allopurinol. There is not a medication that has proven to consistently cure the condition in dogs. Chemotherapy may bring clinical improvement, however relapses regularly occur. Your veterinarian may recommend maintenance therapy with allopurinol, which will help an infected dog remain asymptomatic and decrease the chances of his transmitting the parasite. Should the condition be idiopathic, your veterinarian will recommend regular removal of the affected nail.

Your dog’s recovery from onychogryphosis will be dependent upon the cause of the condition. It is important that you work closely with your veterinarian and follow the recommendations made, in order to achieve the best outcome for your dog. If therapy included removal of a claw it will be essential to keep the area clean and dry.