Oral fungal infections occur when a common yeast, candida, grows out of control in your dog's mouth. Candida is a sugar-digesting yeast that is found in your dog's mouth ears, nose, GI tract and genitals. In normal amounts, the yeast is helpful. But when it multiplies rapidly, it can cause your dog a great deal of discomfort.
If your dog has certain health conditions, like diabetes, he is more susceptible to developing fungal infections. Neutropenia, a viral infection, can lead to the overgrowth of yeast. Damaged skin may provide an opening for a candida infection. Pre-existing oral disease, a suppressed immune system and long-term use of antibiotics can trigger oral fungal infections as well.
If the fungal infection is limited to the mouth, symptoms include drooling, open sores in the mouth, and white, flat areas on the gums or tongue. If the infection is limited to one part of the body, such as the mouth, it is a localized infection. If the fungus exists in more than one area, it is considered systemic. Other areas where the infection can show up are in the ears, whereby the dog will shake his head and scratch, and in the genital tract, which can lead to inflammation of the bladder. Regardless of whether the infection is localized or systemic, your dog will show signs of discomfort.
A trip to the veterinarian is necessary for a diagnosis of oral fungal infections. Your veterinarian will perform a biopsy on the lesions in your dog's mouth and run a urine test. Visible candida colonies in the biopsy, combined with bacteria in the urine, will confirm the diagnosis.
Your veterinarian will want to improve the function of your dog's immune system so he can fight the fungal infection on his own. He will also prescribe topical or oral medication to clear up the existing infection. Finally, he will treat any underlying health condition that may have triggered the overgrowth of yeast, although it isn't always possible to determine what caused it. Fungal infections are stubborn, so your veterinarian will probably recommend treatment to continue for two weeks after all visible symptoms of the infection have gone away.