Malassezia dermatitis occurs secondary to some pathological, immunosuppressive process that causes alterations in the skin or due to certain environmental conditions. Naturally, on the skin and ear canals of our cats we find this yeast as commensal flora while preventing the proliferation of pathogenic fungi. When the malassezia yeast overproliferates under a predisposing process, lesions will appear in our cats, generally with a rancid smell, with scabs, seborrhea, alopecia, redness, itching and self-trauma; It can also affect the ear canal causing otitis. The diagnosis is made by direct visualization of various yeasts per field under the microscope and the treatment seeks to eliminate said overgrowth with antifungals and control the cause that originates it.
In this article on our site we will deal with malassezia in cats, its symptoms and treatment. Keep reading to learn more about this problem that our little cats can suffer.
What is malassezia dermatitis in cats?
This is a pruritic dermatitis caused by the yeast Malassezia pachydermatis, located in the stratum corneum of the skin in cats. This yeast is a regular commensal of our cats' skin, whose presence prevents the development of other pathogenic fungi.
This is a infection that can be located on the face, ears, groin, armpits, extremities, interdigital area and ventral part of the neck.
What causes malassezia overgrowth in cats?
This dermatological problem develops when the yeast malassezia prolifera. Under normal conditions, this overgrowth is inhibited due to a series of factors, such as:
- Fungostatic properties of the cutaneous hydrolipidic film.
- Local immunity with IgA of the apocrine glands.
- Cellular immunity.
- Daily peeling of the skin.
This balance can be altered by certain conditions, such as heat, humidity and a drop in the cat's defenses. In relation to the latter, the overgrowth of malassezia in cats has been related to infections such as feline leukemia, feline immunodeficiency and feline herpesvirus; and for thymomas, paraneoplastic syndromes, and diabetes. This indicates that may be related to underlying immunosuppressive diseases, especially in breeds such as sphinx and devon rex. It can also be caused by immunosuppressive drugs such as corticosteroids.
Cats with itching as in cases of atopic dermatitis are also at higher risk of malassezia overgrowth, as are those with external parasites such as fleas or ear mites or any dermatological disease itchy.
Symptoms of malassezia in cats
Malassezia pachydermatis causes inflammation due to the release of enzyme metabolites such as lipases that alter the hydrolipidic lamina of the skin, to the time it presents surface antigens that generate an immune reaction. In addition, it also produces a proenzyme called zymogen that activates complement, which is a component of the immune system. The itchor is produced by proteolytic substances released by the body during this process.
Clinical signs of malassezia in cats include:
- Feline acne.
- Exfoliative dermatitis.
- Alopecia.
- Erythema.
- Dry or oily seborrhea.
- Self-trauma.
- Paronychia.
- Crusts.
- Hyperkeratosis and hyperpigmentation.
- Liquinification.
- Lesions with rancid smell.
Diagnosis of malassezia dermatitis in cats
The differential diagnosis of a cat with some of the clinical signs described above indicative of malassezia dermatitis includes the following pathologies:
- Adverse reaction to food.
- Flea bite allergy.
- Demodicosis.
- Scabies.
- Superficial pyoderma.
- Atopic dermatitis.
- Keratinization defects.
Also, keep in mind that many of them may be the cause of it.
The diagnosis of malassezia in cats is made, in addition to the cat's symptoms, by cytology with adhesive tape of a sample suspicious lesion or by impression smear. Subsequently, it is observed under a microscope, where the yeast is visualized with an elongated and oval "shoe-shaped" shape with an orifice that is unipolar. If up to 2 yeasts are observed in the field, it is considered normal. A positive test is when a skin sample shows more than 4 or 5 yeasts per field and more than 10 if it is an ear canal sample.
Treatment of malassezia infection in cats
Treatment of malassezia infection in cats is based on the use of antifungals, specifically:
- Systemic ketoconazole at a dose of 10 mg/kg every 24 hours for 3 weeks.
- Oral itraconazole at a dose of 5 mg/kg every 24 hours for 3 weeks.
- Shampoo with ketoconazole or miconazole and 2% chlorhexidine twice a week.
- Topical creams with some imidazole for mild focal lesions.
In some cases, this alone is enough to stop the overgrowth and remission of the lesions. However, in other cases it will be necessary to go further and detect the underlying diseases that are causing the overgrowth, treating them specifically and controlling malassezia dermatitis in cats with shampoos
In the case of otitis due to malassezia, antifungals such as miconazole, nystatin or clotrimazole should be used, combined with antibiotics and corticosteroids for secondary infections and itching, successively.
In no case should the cat self-medicate, since it must be a professional who diagnoses the proliferation of yeast and determines the best treatment.
