Demodectic Mange in Felines in Santa Catarina State, Brazil

Abstract

Background: Demodicosis is a parasitic dermatopathy often found in dogs and considered rare in felines. It is caused by the mite of the genus Demodex. In cats, it can be caused by 3 species: Demodex cati, Demodex gatoi, and another Demodex species not yet named. Demodicosis can be associated with systemic diseases, which can compromise the animal's immune system, as is the case of demodicosis caused by Demodex cati. The present case report describes 3 cases of demodicosis, 2 by D. cati and 1 by D. gatoi, with pruritic lesions and abrasions in different parts of the animals' bodies, but which showed improvement with common treatment.

Cases: The first 2 cases refer to feline patients treated in Curitibanos and the third in Blumenau, both municipalities located in Santa Catarina. The first patient, a 6-year-old female, SRD, IVF/FeLV-negative, presented abrasions and alopecia in the cervical region, at the base of the auricle and submandibular region, with pruritus for 3 months. Skin scraping was performed revealing presence of Demodex cati. The second patient, a 11-year-old male, SRD, FIV-negative and FeLV-positive, presented alopecic lesions with mild pruritus, 1 on the dorsal region of the head and 2 others slightly oval on the tail. A skin scraping was performed for parasitological examination which demonstrated the presence of mites of the species Demodex cati. The third patient, a 10-month-old male Persian, IVF/FeLV-negative, had alopecic and pruritic lesions on the back and head near the auditory canal, as well as signs of external otitis. The lesions on the skin were scaly and presented a blackish appearance, with evolution of a few weeks. Skin scraping was performed for parasitological examination, confirming the presence of Demodex gatoi. In all cases, fungal cultures were negatives. For the 3 patients, fluralaner was used transdermally, as a pipette with a single application, and all showed complete improvement within 30 days after administration.

Discussion: Demodicosis is considered a rare disease among felines and the literature suggests involvement when linked to immunosuppressive causes, such as viral diseases or systemic comorbidities. Still, it can become the cause of bacterial or fungal co-infections due to immunological impairment. In the 3 cases reported, only 1 patient was positive for FeLV. Parasitological examination of the skin by deep or superficial skin scraping, considered as the diagnostic method of choice for demodicosis, was performed in the 3 patients and demonstrated the presence of mites. Although the literature does not provide treatment considered to be of choice for felines, fluralaner was prescribed transdermally for the 3 patients reported here due to its practicality and prolonged time of action, administered in single application as antiparasitic therapy, achieving success and complete improvement up to 30 days after its use. The animals that presented co-infections were treated according to the type of infections they presented and their therapies of choice.

Keywords: dermopathy, Demodex cati, Demodex gatoi, cat, fluralaner.

Título: Sarna demodécica em felinos em Santa Catarina, Brasil

Descritores: dermatopatia, Demodex cati, Demodex gatoi, gato, fluralaner.