Case report: Disseminated dermatophytosis in a dog

Abstract

Dermatophytosis is a contagious fungal infection that affects dogs and cats, with zoonotic potential. Caused by Microsporum, Trichophyton, and Epidermophyton, it affects the skin, hair, and nails, and istransmitted through direct contact or fomites. Meg, a 10-year-old female Shih Tzu, was referred to a veterinarian due to hair loss, a feeling of cold, apathy, and intense itching. After a biopsy, Meg was treatedfor severe dermatophytosis and began receiving antifungals. Although her respiratory condition improved, the sneezing persisted. After adjustments to the treatment, Meg showed significant improvement, with no alopecia or itching, and was considered cured on August 6, 2024. After multiple treatments and an initialdiagnosis of ehrlichiosis, the symptoms persisted, leading to a biopsy that confirmed severedermatophytosis. The antifungal treatment and environmental support resulted in complete recovery. The discrepancy between the negative fungal culture and the presence of fungal hyphae in the histopathologyemphasizes the need for multiple diagnostic methods in dermatology. The case highlights that thecorrelation between clinical findings and laboratory tests is crucial for accurate diagnosis and effectivetreatment, ensuring a good prognosis for the patient.