Dog nails

Dog Nail Discoloration – What does it mean?

Nail color depends on the amount of melanin pigment that is generated in the cells by melanocytes. It may be the same throughout life or can be changed, so the color of nails or skin becomes darker or lighter, depending on the activity of melanocytes. Such changes may be normal, but they also occur in some diseases. Some endocrine diseases, such as hypothyroidism or Cushing’s syndrome, can cause nail discoloration, but also other symptoms such as obesity, increased water intake and urination, frequent skin infections, hair loss, etc.

Furthermore, bacterial and fungal infections, atopias, and autoimmune diseases can be the cause. In bacterial infections, pain is usually present and discharge or pus coming out of the nail bed is very common.

In fungal diseases, the formation of hairless spots on the finger around the nail occurs. The nail itself becomes brittle, can change color or grow irregularly.


The most common cause of nail changes. Usually one nail is involved which is broken and sore. Diagnosis is clinically simple, and therapy consists of removing the cracked part of the nail and placing a temporary bandage to stop the bleeding. Usually a systemic antibiotic is also prescribed to prevent secondary bacterial infection.
Bacterial infection

It is common in dogs, rarely in cats. In cats it is often associated with immunodeficiency / FeLV-FIV infection, diabetes mellitus ../ and in dogs it can be idiopathic or secondary as a result of some underlying disease / Hypothyroidism, Cushing, Leishmaniasis … /. Changes are observed on multiple nails, and pain is a primary feature. The diagnosis is made on the basis of cytological examination of purulent discharge in the nail, bacterial culture, and response to antibiotic therapy. Therapy is based on the removal of a cracked nail, local antibacterial therapy and long-term systemic antibiotic therapy. In any case, especially if the disease returns after stopping therapy, the root cause should be sought. If the areas between the fingers and the surrounding skin are also affected, demodicosis and allergic diseases should be excluded.

Fungal diseases

The fungus is a relatively rare cause of nail disease in the dog, and usually a hairless spot on the affected finger is noticed. In fungal diseases, the therapy is long-lasting, and is carried out until a healthy nail begins to grow out of the diseased site.

Atopic dermatitis

Atopic dermatitis or food hypersensitivity may underlie inflammatory changes in the paws and consequently the nails. Namely, in addition to the deformation of the nail, reddish coloration of the nail and surrounding hair can occur, suggesting a secondary infection with yeast Malassezia. Of course, diagnosis is made on the basis of symptoms and suspected allergy, using allergy tests (intradermal and serological) and elimination diet.

Autoimmune diseases

Autoimmune diseases of which the most common is “Symmetric lupoid onychodystrophy”. The term “symmetrical” in this case means that two or more paws are involved, which is why we sometimes this disease refers to the disease of 20 nails. Nails are deformed, cracked, and are painful to the touch just before they fall off, but after that this soreness is usually lost. The cause is, in principle, unknown, but it is believed that it is often underpinned by autoimmune reactions, as well as infections, vaccine reactions, or various allergies. It is considered that there is no breed and gender predisposition, even though it appears that the incidence is slightly higher in large breeds (especially German Shepherd and Labrador Retriever).

In the end, it can be concluded from this that the color change in your dog may have different causes. To determine if it is a health problem, it is necessary to take the dog to a veterinarian for an examination. When examining a nail, it is important to determine if it involves changing one or more nails. A complete clinical examination of the dog can determine whether it is a systemic disease that may also manifest through the nails.

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