Yeast Dermatitis/Malassezia Dermatitis In Dogs: What are the Causes and Treatment Options?
Wed, April 14, 2021

Yeast Dermatitis/Malassezia Dermatitis In Dogs: What are the Causes and Treatment Options?

 

Malassezia pachydermis or yeast dermatitis is caused by the fungus Malassezia pachydermatis and it is also a common cause of skin diseases among dogs, explained Tammy Hunter, DVM, and Ernest Ward, DVM of VCA Hospitals, an operator of more than 750 animal hospitals in the US and Canada.

Malassezia pachydermatis is typically found on your dog’s skin; however, its abnormal overgrowth can cause skin inflammation or dermatitis. Some breeds of dogs such as poodles, basset hounds, West Highland white terriers, cocker spaniels, and dachshunds are predisposed to this disease, stated Pet MD, an online pet resource.

Prevalence of Malassezia pachydermatis In Dogs In Slovakia

Eva Conkova and colleagues of journal portal Research Gate wrote that 189 samples from 147 dogs were examined between June 2005 and June 2007. The swabs were extracted from the skin and/or external ear canal of dogs examined at the Small Animal Clinic of the University of Veterinary Medicine and Pharmacy in Kosice, Slovak Republic. Cytological and mycological analysis were extracted from skin with pathological lesions (131 samples) and from the external ear canal (58 samples).

The main criteria for including dogs in Conkova and colleagues’ study were dermatitis, alopecia, seborrhea with an accompanying sweetish odor, and/or otitis with dark brown thick cerumen accumulated in the ear canal.

The dogs’ age, sex, breed, and the presence of main clinical symptoms (pruritus, erythema, alopecia,  hyperpigmentation, seborrhoea, sweetish odor, and dandruff) were also documented. The prevalence of M. pachydermis was more prevalent in males (45.2%) than in females (35.2%). The prevalence was highest during autumn (52.6%), followed by spring (36.1%), summer (27.3%), and winter (45.7%). M. pachydermis was higher in long-haired (51.5%) and short-haired dogs (45.9%) than in smooth-haired dogs (21.4%).

The prevalence was highest in samples from the trunk area (60.3%). Samples were also found in the interdigital area (28.6%), face (25%), the axillary area (17.6%), and the inguinal area (5.9%) Regarding ear swabs samples, higher prevalence of M. pachydermis was found in dogs with pendulous ears (51.4%) than those with erected ears (34.8%), albeit the difference was not significant, Conkova and colleagues said.

All cytological and mycological samples were classified by cytological examination (26 of ear swabs and 46 of skin swabs). 9.8% (five out of 58) of culture positive skin swabs were cytologically classified as “negative,” as samples that were mycologically positive were not detected by cytological examination.

 

 

Of 51 dogs, clinical signs that accompanied M. pachydermis were seborrhea (54.9%), alopecia (49.0%), pruritus (41.2%), sweet odor (33.3%), erythema (27.5%), and hyperpigmentation (5.9%). M. pachydermis is the most frequent yeast isolated among canines. Factors that contribute to the development of infection may be helpful in diagnosis.

 

What Are the Causes and Signs of Yeast Dermatitis?

The exact reasons behind yeast dermatitis are not known but it is correlated to allergy, seborrhea, and possibly congenital and hormonal factors. High humidity and temperature may increase the likelihood of yeast dermatitis. Concurrent infections and food and flea allergies may also be a contributing factor to this disease.  

The clinical signs of yeast dermatitis are itching and redness, flaky skin, hyperpigmentation, chronic or recurrent otitis externa or ear infections, and musty discharge from lesions. In severe cases, epidermal thickening is also a sign of yeast dermatitis.

 

How Can My Dog Get a Yeast Skin Infection?

Your dog’s skin is a host to numerous bacteria and fungi. Normally, these do not cause a problem thanks to your canine’s immune system. However, the bacteria and fungi can cause infection if your dog’s immune system is suppressed or when the skin’s condition changes. 

A yeast infection occurs when the number of yeast organisms on your dog’s skin multiplies. Yeast skin infection causes the amount of oils produced on the skin to increase, which is often associated with allergic skin disease. Excess oils can also cause seborrhea oleosa. Your dog cannot get a yeast infection from another dog since yeast dermatitis is not a contagious disease.

 

 

How Will My Dog Be Diagnosed With Yeast Dermatitis?

There are several techniques to aid in the diagnosis of yeast dermatitis. Your veterinarian may scrape your dog’s skin with a blade to collect yeast organisms. Another technique is impression smear, which involves pressing a microscope slide on the skin to collect samples. A moistened cotton swab can also be rubbed on the skin to collect yeast samples.

Acetate tape preparations can be performed by your vet by placing a piece of clear tape to the skin to collect yeast samples. Finally, a skin biopsy can be performed to collect samples. This is done by getting a small piece of skin with a biopsy punch. It is the most invasive diagnostic test, but a skin biopsy provides the “most complete diagnostic information.” The sample is then examined by a veterinary pathologist under the microscope.

Be sure to give a comprehensive history of your pet canine’s health, as well as the onset and nature of the symptoms to your veterinarian.

 

How Is Yeast Dermatitis Treated?

1.     Topical Treatment

Medicated shampoos are an important part of treating yeast dermatitis. If your dog has greasy or oily skin, it will need to be “degreased” with a shampoo containing selenium sulfide or benzoyl peroxide. After that, your dog will need to be bathed again with an anti-fungal shampoo containing chlorhexidine, miconazole, or ketoconazole.

Your dog’s anti-fungal shampoo should remain in contact with the skin for no less than 10 minutes. This treatment should be done every three to five days for two to 12 weeks. A topical ointment may be given if the infection occurs in your dog’s ears or in only one or two spots on its skin.

2.     Oral Treatment

Oral or systemic anti-fungal medications are administered in cases of severe, chronic, or recurring cases of yeast dermatitis. Many dogs with this disease will also be afflicted with bacterial skin infection or pyoderma. Antibiotics will be needed to treat the infection for about four to 12 weeks. 

Oral medications include ketoconazole, itraconazole, and fluconazole. The aforementioned medications are effective, but they can cause side effects—particularly in the liver. Dogs with advanced or chronic yeast dermatitis are prescribed with both oral and topical medications. 

 

 

How Is Yeast Dermatitis Managed?

It is recommended to have regular visits to your veterinarian, enabling them to evaluate the disease and the treatment’s progress. Your veterinarian will examine your pet and perform a skin cytology test to confirm the reduction of the number of causative organisms. 

Recurrence is common so be sure to observe your dog for any untoward symptoms. If you do, call your veterinarian.


Your dog is more vulnerable to yeast dermatitis depending on its breed or the season. Treatment aims to reduce the number of yeast and bacteria, as well as to control the condition. Don’t change your dog’s treatment plan or change any prescribed medications without consulting your veterinarian.