PATHOLOGIES WE TREAT
Malassezia Dermatitis
Introduction
Malassezia dermatitis is one of the most common causes of skin and ear problems in dogs and cats. These infections are typically caused by Malassezia pachydermatis, a yeast that is part of the normal skin and mucosal flora in dogs. However, under certain conditions, this yeast can overgrow, leading to irritation and inflammation.
Causes
Malassezia is a fungus that naturally resides on the skin of dogs and cats. Under normal conditions, it does not cause harm, but certain factors can trigger overgrowth, leading to infection. Common triggers include:
- Humidity and moisture.
- Excessive oil production in the skin.
- Weakened immune system.
Some breeds, such as West Highland White Terriers, Dachshunds, Cockers, and German Shepherds, are more prone to these infections.
Symptoms
Malassezia dermatitis may be localized or generalized. Commonly affected areas include the face (ear canal and perioral skin), armpits, ventral neck, and distal limbs (interdigital spaces and nails). Symptoms vary but often include:
- Intense itching: Pets may scratch constantly, especially in affected areas.
- Redness and inflammation: Skin irritation and redness are common, especially on the paws, neck, and armpits.
- Strong odor: Infected areas often emit an unpleasant odor, which is particularly noticeable in the ears.
- Scaly or greasy skin: The skin may feel oily or show visible flakes.
- Recurrent ear infections: Ear infections caused by Malassezia often involve dark discharge and a strong smell.
Diagnosis
Diagnosis is performed by a veterinarian and includes:
- Clinical history and visible skin lesions.
- Cytology: Skin samples are examined under a microscope, revealing yeast cells with a characteristic "shoeprint" shape. A high number of these organisms confirms Malassezia dermatitis.
- Additional tests: May include blood and urine analysis to rule out underlying conditions contributing to yeast overgrowth.
Veterinarians also review any current treatments, particularly immunosuppressive medications such as corticosteroids, which can predispose pets to infections.
Treatment
Treatment involves a combination of therapies:
- Topical therapy:
- Antifungal and antiseptic shampoos and lotions containing ketoconazole or chlorhexidine are essential.
- Products like Skinnia Calm can soothe redness and irritation, promoting comfort and healing.
- Systemic antifungals: In severe cases, oral antifungals like itraconazole may be prescribed.
- Addressing underlying causes: Treating allergies, hormonal imbalances, or other contributing factors is crucial to prevent recurrence.
Prevention
To reduce the risk of Malassezia dermatitis:
- Keep skin clean and dry: Especially in moisture-prone areas like the paws and armpits.
- Use appropriate care products: Choose pet-specific products that maintain a healthy skin balance.
- Inspect and clean ears regularly: Particularly in breeds with floppy ears.
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Bond, R. (2021). Malassezia dermatitis. In Greene's Infectious Diseases of the Dog and Cat (pp. 978-986). WB Saunders.
Guillot, J., & Bond, R. (2020). Malassezia yeasts in veterinary dermatology: an updated overview. Frontiers in cellular and infection microbiology, 10, 79.
Bioadhesive transparent gel indicated to moisturise, protect and soothe the dry skin of small animals.