Friday, January 4, 2013

Dog Yeast Infection - A Pet Owner’s Guide to Understanding Dog Yeast Infection

Behind every yeast infection are single-celled fungi that are found in virtually every living creature on Earth. The truth is, yeast infection in both humans and animals normally appear in warm, moist areas of the body. In humans, yeast infection usually develops in the mouth and genitals whereas in animals such as dogs, signs of yeast infection are commonly seen on the skin and the ears.

Unlike yeast infections in humans, dog yeast infection is caused by a fungus called Malasezzia pachydermatis. Interestingly enough, this fungus made its appearance in the dermatology scene roughly 10 years ago, although it may have been in existence a lot longer. In dog's ears, Malasezzia is considered a secondary pathogen. In the skin, however, it is now regarded as a primary one despite the fact that there is usually a predisposing factor that turns it from a harmless bystander into an extremely itchy and irritating nuisance.

Malasezzia pachydermatis rarely cause an infection when the dog is in healthy condition. However, when the conditions on the dog's skin surface change and favor the growth of yeasts, these opportunistic organisms multiply in large numbers and cause dog yeast infection. Remember, Malasezzia in small numbers is harmless, but when they proliferate and get out of control, disease results.

So, what are some conditions that lead to dog yeast infection? Increased skin oil production, which is often associated with allergic flare ups, is usually the most common factor that increases a dog's susceptibility to yeast infections. As with humans, hormonal imbalances and decreased immune function also predispose a dog to yeast infections.

Although Malasezzia yeast infection can affect any type of dog, the following breeds are known to be genetically predisposed to yeast infections: West Highland White Terriers, Basset hounds, Poodles, Silky terriers, Australian terriers, Malteses, Cocker spaniels, Chihuahuas, Shetland sheepdogs, and Dachshunds.

Skin Yeast Infection in Dogs

Yeast infection in skin of dogs is usually manifested by the following symptoms: skin irritation and itchiness (as evidenced by frequent scratching), loss of hair (alopecia), scaly skin, oily skin, redness on the affected areas, smelly discharge from lesions, hyperpigmentation (patches of skin becoming darker) and epidermal thickening (in chronic cases). Skin yeast infection in dogs usually occurs on the underside of the neck, the belly, and the feet, particularly between the toes.

Diagnosis of skin yeast infection in dogs is based on various tests such as impression smear and tape strip cytology, among others. The skin of affected dogs can be cleared from Malasezzia with the use of ketoconazole for 10 to14 days or application of topical shampoos that contain miconazole or ketoconazole. Because most cases of skin yeast infection in dogs are secondary to an underlying disease, recurrence is very common unless the cause is resolved.

Ear Yeast Infection in Dogs

It is relatively easy to spot an ear yeast infection in dogs, especially when it occurs in the outer ear. If you may notice your dog scratching his ear or rubbing it on the floor, that may indicate that your pet may have an ear yeast infection. Changes in behavior such as lack of interest in people, trouble walking, difficulty hearing, and loss of balance may also be indicative of infection.

Diagnosis of ear yeast infection involves the use of an instrument called otoscope. To determine if your dog's ear drum is intact or if there's something in the ear canal that could be causing the infection, your veterinarian will look at your dog's ear canal using an otoscope. The doctor will probably also take a sample of discharges from in and around the ear, and examine this under the microscope. If the infection is confined in the outer ear, antifungal creams and ointments will usually suffice. If the infection is found in the middle ear, however, systemic medications in the form of tablets or injections are usually prescribed. Full cleaning of the dog's ear canal may also be recommended.

Dog yeast infections are usually associated with the skin and ears. Fortunately, these conditions can be easily prevented with healthy diet. If you suspect yeast infection in your dog, be sure to contact your vet immediately for proper evaluation and treatment.