Citologia e histologia no diagnóstico de afecções dermatológicas em cães de abrigos de Lavras - MG

Abstract

Dermatological conditions in shelter dogs represent a complex challenge to animal welfare and One Health, given the high stocking density and the risk of zoonoses. This study aimed to characterize the dermatopathological profile of shelter dogs in Lavras-MG, integrating two studies: a retrospective survey and a systematic prospective approach to evaluate the use of cytopathology and histopathology as diagnostic tools. The retrospective survey analyzed nodular lesion records (162 dogs; 168 diagnoses; 2014-2024) from the Veterinary Pathology Sector (SPV/UFLA) and non-nodular records (n=50; 2019-2024) from the Clinical Pathology Sector (SPC/UFLA) of the Federal University of Lavras. There was a higher frequency of neoplastic processes (50.59%; 85/168) in nodular lesions, notably Transmissible Venereal Tumor (TVT) (14.11%; 12/85) and mast cell tumor (10.58%; 9/85), while a high number of negative results for ectoparasites and dermatophytes (74.00%; 37/50) was identified in nonnodular conditions. In the prospective study, conducted from November 2024 to May 2025, the screening of 260 dogs revealed a prevalence of 30.76% (80/260) of animals with active dermatological lesions, totaling 90 sampled conditions. In prospective nodular conditions, an inversion of the epidemiological profile was observed due to the mitigation of referral bias, with follicular cysts consolidating as the most frequent individual finding (24.44%; 11/45), followed by lipoma (15.55%; 7/45). In prospective non-nodular conditions, there was a prevalence of bacterial and parasitic inflammatory processes, with 48.78% (20/41) of samples testing negative for agents, consolidating cytopathology as a mandatory step in the diagnosis by exclusion for allergic, endocrine, or immune-mediated dermatopathies. Fine-needle aspiration (FNA) was the most used technique for nodular collection (73.33%; 33/45), with a diagnostic yield of 84.44% (38/45). Passive demand reveals a bias toward high-impact clinical conditions, such as TVT and mast cell tumor, while the high negativity rate (74%) in nonnodular cases reflects both the masking of complex etiologies and the intrinsic difficulty in detecting agents in superficial or chronic presentations. Conversely, active surveillance exposes a silent burden of benign lesions (cysts and lipomas) and parasites of One Health relevance, such as sarcoptic mange. In this context, cytopathology establishes itself as a tool for oncological screening and diagnostic exclusion for allergic, immune-mediated, or endocrine dermatopathies, while histopathology remains the gold standard for definitive diagnosis and prognostic determinations. Keywords: cytopathology; skin diseases; veterinary diagnosis; screening; shelter medicine.