Canine Skin Fungal Diseases

Fungal infections can be easy to treat or deadly to dogs. Some infections can be spread between pets and people, so it's important to have any changes in skin condition checked out by your veterinarian to rule out serious fungal infections. Fungal infections are treated with an anti-fungal medication that's given orally, applied to the skin (such as creams or sprays) or injected into the skin. Always inquire about exact instructions for any medication given to your pet.

  1. Ringworm

    • Contrary to popular belief, ringworm is not a worm but rather a type of fungus. Ringworm is the most common fungal infection occurring in dogs. It is highly contagious and can spread from animal to animal as well as from animal to human and vice versa. The most common symptom of ringworm is a round, red skin lesion. These lesions cause a loss of hair and can also have a scaly appearance.

      Treatment for ringworm is relatively easy. Some dogs will heal on their own if there are only one or two lesions. For dogs who have widespread lesions, your vet may prescribe a topical anti-fungal medication. The fur will need to be trimmed for the medication to fully penetrate down to the skin. Time for recovery will vary from dog to dog depending on the severity of the fungal infection.

    Yeast Infections

    • Yeast, though common on the skin, can grow rapidly and cause an infection under the right conditions. Yeast infections can occur anywhere but most often occur in the reproductive organs, the ears, the eyes, the nose and or the skin. Symptoms in dogs include a loss of hair, redness or blackened skin (hyperpigmentation,) and occasionally a thickening of the skin. Additional symptoms include a strange and unpleasant greasy smell, scaly skin, oily skin and mild to intense itching.

      For a yeast infection of the skin, most veterinarians will prescribe an anti-fungal cream that you will need to apply for up to seven weeks. In addition to this, you may also receive various oral medications, such as anti-inflammatory drugs or antibiotics, depending on the severity of the fungal infection and whether or not other infections have occurred.

    Sporotrichosis

    • Fortunately, sporotrichosis is relatively rare, but it has the potential to infect cats, dogs and their human counterparts. The fungus enters the skin through an open wound such as a cut, scratch or a bite from another infected animal. The most common symptom is a small nodule that can drain a fluid that may be cloudy or clear. There are often several of these nodules present. Unfortunately, such skin lesions are also associated with a large variety of bacterial, viral and fungal infections not only to the skin but to other parts of the body, leading to frequent misdiagnosis.

      Sporotrichosis is treated with oral medication containing potassium iodide that is administered for up to eight weeks. However, the treatment is not always successful.

    Blastomycosis

    • Blastomycosis causes lesions that can occur on the skin, the eyes or within the respiratory system. This fungus spreads rapidly through the body and is often deadly; a majority of dogs will not recover after the initial infection. Blastomycosis occurs when the dog inhales the spores that are found in the soil of areas that are close to water, such as a swamp. After an infection to the lungs has occurred, the fungus then spreads to the skin, the eyes, and various tissues in the body including the brain, the lymph nodes and, in severe cases, into the bones.

      Symptoms include fever, depression, lack of appetite and accompanying weight loss as well as eye problems, skin lesions or other skin issues, and mild to severe coughing. Skin lesions will drain fluids, and some will become inflamed. In some dogs, lameness will occur after the bones have become infected. For the few dogs who are diagnosed, a vet will prescribe oral or injected anti-fungal medications; however, not all dogs will recover.

    Zygomycosis

    • Zygomycetes fungi live in the soil and on decaying plants. Dogs with a healthy immune system will usually kill off any fungi that enter the system before they are given a chance to cause an infection, making this skin condition relatively rare. Common symptoms include vomiting, jaundice and pneumonia as well as skin lesions that drain and may become irritated. These same lesions may also appear in the lungs, on the liver, in the gastrointestinal tract or the lymph nodes.

      Zygomycosis is often a fatal fungal infection, and the lesions must be removed surgically. After removal of the lesions, your vet will administer medication; however, recovery is not guaranteed.