Virbac Dermatophytest to identify ringworm fungi in pets

Product Overview and Diagnostic Utility

Dermatophytest is a dermatophyte-selective culture medium designed for the specific growth of fungal species belonging to the genera Microsporum and Trichophyton.

• Target Species: Cats, dogs, lagomorphs (rabbits), and rodents (guinea pigs, mice, etc.).
• Target Pathogens: Specifically identifies Microsporum canis, Microsporum gypseum, Microsporum persicolor, and Trichophyton mentagrophytes.
• Diagnostic Function: Identifies the fungal agents responsible for dermatomycosis (ringworm) across various pet species.
• Mechanism of Action: Selective compounds in the agar limit the growth of unwanted contaminants, such as bacteria and non-dermatophytic fungi.
• Visual Interpretation: Color change in the agar indicates dermatophyte growth, typically occurring within 2 to 14 days.
• Microscopic Confirmation: Colonies on the agar surface can be easily sampled for microscopic observation to confirm species identification.
• Usage Restriction: For veterinary use only.

Clinical Background and Zoonotic Importance

• Pathogenous Nature: Dermatomycoses are caused by Microsporum and Trichophyton species. Infections are highly prevalent in domestic pets.
• Zoonotic Risk: Transmission to humans is common, especially with Microsporum canis and Trichophyton mentagrophytes, which are major zoonotic agents.
• Disease Progression: Spores shed into the environment invade keratinized structures (hair follicles, stratum corneum, claws), forming hyphae that produce chronic lesions.
• Asymptomatic Carriers: Healthy animals may carry spores and infect humans or other animals. Testing compatible lesions helps establish sanitary controls to prevent environmental spread.
• Diagnostic Reliability: Fungal culture is the most reliable diagnostic method for dermatophytes, overcoming the limited sensitivity and technical difficulty of direct microscopic examination. Sample collection sites can be selected using a Wood's lamp.

Indications for Use

Culture with Dermatophytest is indicated in the following clinical scenarios:

• Clinical Suspicion: Presence of localized or multifocal alopecia, crusty or scaly dermatoses, seborrhea, or claw deformations.
• Treatment Decisions: Evaluating the necessity of systemic or topical antifungal therapy in secondary or complex lesions.
• Screening Carriers: Identifying asymptomatic or mechanical carriers to mitigate zoonotic risks to owners and vulnerable individuals.
• Diagnostic Integration: Final diagnosis of ringworm should integrate culture results with clinical signs and complementary veterinary examinations.