Introduction
Veterinary mycology is the branch of microbiology that studies fungi of interest in veterinary medicine, including their biology, mechanisms of pathogenicity, diagnosis, and control of mycoses affecting domestic, wild, and production animals (Quinn et al., 2011).
Fungi are heterotrophic eukaryotic organisms widely distributed in the environment. Although many are saprophytic or commensal, certain species can behave as opportunistic or primary pathogens, causing cutaneous, subcutaneous, and systemic infections with significant clinical and zoonotic impact (Zachary & McGavin, 2017).
In veterinary practice, mycology is essential for the differential diagnosis of dermatological, respiratory, and systemic diseases, as well as for the correct implementation of antifungal treatments and biosecurity measures (Quinn et al., 2011).
General characteristics of fungi
Fungi are eukaryotic organisms that possess a cell wall composed mainly of chitin, glucans, and mannans, and a plasma membrane rich in ergosterol. These structural characteristics differentiate them from bacteria and animal cells and constitute therapeutic targets for antifungal drugs (Tortora et al., 2021).
Fungal nutrition is heterotrophic by absorption. Fungi secrete extracellular enzymes that degrade organic matter, allowing nutrient absorption. Reproduction can be asexual, sexual, or both, through the formation of spores, which facilitates environmental dissemination (Quinn et al., 2011).
Mycological classification of veterinary interest
Yeasts are unicellular fungi that reproduce mainly by budding. In veterinary medicine, notable species include Malassezia pachydermatis, associated with otitis and dermatitis in dogs, and Candida spp., involved in opportunistic mucocutaneous and systemic infections (Zachary & McGavin, 2017).
Filamentous fungi are composed of hyphae that form a mycelium. Among them are dermatophytes such as Microsporum and Trichophyton, responsible for dermatophytosis or ringworm, one of the most common mycoses in small animals and of high zoonotic importance (Quinn et al., 2011).
Dimorphic fungi can occur as mold in the environment and as yeast in host tissues. Relevant examples include Histoplasma capsulatum and Blastomyces dermatitidis, agents of severe systemic mycoses in animals and humans (Tortora et al., 2021).
Main veterinary mycoses
Cutaneous mycoses, especially dermatophytosis, affect skin, hair, and nails. Clinically, they manifest with alopecia, scaling, erythema, and pruritus, being common in dogs, cats, and young or immunosuppressed animals (Zachary & McGavin, 2017).
These occur after traumatic inoculation of fungi present in the environment. They include infections such as sporotrichosis, characterized by nodular lesions that follow lymphatic vessels, with clinical and zoonotic importance (Quinn et al., 2011).
Systemic mycoses affect internal organs such as the lungs, liver, and nervous system. They are often severe and potentially fatal, especially in immunocompromised animals, requiring early diagnosis and prolonged treatment (Tortora et al., 2021).
Mycological diagnosis in veterinary medicine
Detailed clinical evaluation, together with skin, ear, or secretion cytology, allows preliminary identification of fungal structures such as yeasts and hyphae, guiding the initial diagnosis (Zachary & McGavin, 2017).
Culture on specific media such as Sabouraud agar is essential for definitive identification of fungal species. Complementary techniques such as histopathology, immunohistochemistry, and molecular tests improve diagnostic accuracy (Quinn et al., 2011).
Clinical and veterinary importance
Treatment of veterinary mycoses requires appropriate selection of topical or systemic antifungals, considering the animal species, etiological agent, and duration of treatment to prevent relapses and antifungal resistance (Tortora et al., 2021).
Many veterinary mycoses, such as dermatophytosis and sporotrichosis, have zoonotic potential; therefore, timely diagnosis is essential for the protection of public health and veterinary personnel (Quinn et al., 2011).
Conclusion
Veterinary mycology constitutes a fundamental pillar in the diagnosis and management of numerous infectious diseases in animals. Knowledge of fungal biology, the most frequent mycoses, and diagnostic tools allows veterinarians to address these pathologies effectively and responsibly (Zachary & McGavin, 2017).
References
Quinn, P. J. et al. (2011). Veterinary Microbiology and Microbial Disease. Wiley-Blackwell.
Tortora, G. J. et al. (2021). Microbiology: An Introduction. Pearson.
Zachary, J. F., & McGavin, M. D. (2017). Pathologic Basis of Veterinary Disease. Elsevier.