Fungal Infections in Dogs

Fungal infections in dogs range from skin infections such as yeast infections to more complicated infections such as blastomycosis, that affect the lungs. These infections are caused by fungi of different types and may be treated with fungicides.

Yeast Infection

Yeast infections are the most common fungal infections in dogs. The infection is caused by Malassezia pachydermatis, which is a type of yeast that is normally present on the dog’s skin, but when there is an overgrowth, the yeast infection occurs.

A yeast overgrowth may be caused by antibiotics, humidity and a weakened immune system.

The symptoms of yeast infections include itchy skin, rashes and oily or scaly skin. The infection may be localized in the ears, muzzle, paws, or the genital or anal area.

The treatment contains fungicides and fungal creams and the treatment can be lengthy as restoring a normal yeast balance can be difficult.


The ringworm is caused by fungi and is not a worm as the name suggests; the fungi are present on the surface of the skin and is transmitted though direct contact. The ringworm may be transmitted to humans, so it is a zoonotic disease.

The ringworm infection will cause bald patches that are ring shaped, skin lesions and itchiness.

Antifungal medication should be administered for proper treatment.


Blastomycosis is a fungal systemic disease that can occur in dogs and humans.

The fungi may be found in moist areas and sand or near water and a dog may be infected through direct contact with the soil or sand.

The fungi can cause respiratory problems and numerous lesions. The infection can be fatal, as the fungi affect the lungs.

Common symptoms of blastomycosis include fever, lethargy, lameness, coughing, panting, skin and eye problems.

Blastomycosis requires antifungal medication.


Coccidioidomycosis also known as valley fever causes respiratory disease in canines.

The fungi causing the disease are found in humid soils and can be contracted through direct contact with infected soils or dogs.

The disease has symptoms that are similar to pneumonia symptoms such as:

  • Coughing
  • Swollen lymph nodes
  • Skin lesions

Dogs need oral antifungicides to get rid of the valet fever.  

Other less common fungal infections in dogs include:

  • Aspergillosis, which affects the sinuses
  • Cryptococcosis that causes neurological and vision problems, but affects only immuno-suppressed pets
  • Histoplasmosis that will affect the lungs and will cause respiratory disease and intestinal problems
  • Pythiosis, a very rare fungal infection that can have fatal effects; the fungi are found in stagnant water and will cause gastrointestinal problems
  • Sporotrichosis, also rare but can affect humans also; it manifests through nodes on the head area and the nodules can become ulcerated
  • Zygomycosis is a rare skin fungal infection that can be healed without treatment

In case you suspect that your pet has a fungal infection, consult a vet. Also, make sure to wear surgical gloves when handling the pet, as some of these fungi may be transmitted to humans. Even if some of these fungal infections can go away on their own, you need to get some medication to relieve your dog’s discomfort.