NAVLE Integumentary

Feline Dermatophytosis Study Guide

Dermatophytosis (commonly known as ringworm) is a superficial fungal infection of keratinized structures including skin, hair, and nails in cats. Despite its common name, this condition is not caused by a worm but by fungi called dermatophytes.

Overview and Clinical Importance

Dermatophytosis (commonly known as ringworm) is a superficial fungal infection of keratinized structures including skin, hair, and nails in cats. Despite its common name, this condition is not caused by a worm but by fungi called dermatophytes. This is a high-yield NAVLE topic due to its clinical prevalence, zoonotic potential, and importance in shelter medicine.

Microsporum canis is the causative agent in greater than 90% of feline dermatophytosis cases. The disease is self-limiting in immunocompetent cats (typically resolving within 4 months) but treatment is always recommended to shorten clinical course, reduce environmental contamination, and prevent zoonotic transmission.

High-YieldDermatophytosis affects less than 4% of cats with skin disease - it is NOT the most common feline skin condition despite popular belief. FIV/FeLV status alone does NOT increase risk of dermatophytosis.
Classification Species Clinical Significance
Zoophilic Microsporum canis Greater than 90% of feline cases; cats are natural reservoir; highly zoonotic; fluoresces under Wood's lamp
Zoophilic Trichophyton mentagrophytes Less common; rodent reservoir; does NOT fluoresce
Geophilic Microsporum gypseum Soil reservoir; sporadic infections; does NOT fluoresce

Etiology and Pathogenesis

Causative Organisms

Dermatophytes are keratinophilic fungi that utilize keratin as a nutrient source. They are classified by their natural reservoir:

You've been studying hard

Create a free account to keep reading

Free accounts get 5 articles/day + daily practice question

Join 14,000+ vet students already studying with NavleExam.

No credit card needed — free account takes 30 seconds.

Create Free Account — Keep Reading Already have an account? Log in
or skip signup — just get daily questions

No spam. One question per day. Unsubscribe anytime.

NAVLE Exam Prep Platform

Everything you need to pass the NAVLE

10,000+ Practice Questions
Exam-style with full explanations
Past Exam Papers
Real previous exam questions
Flashcard Mode
Species & topic quick review
High-Yield Study Guides
What's actually on the exam
Start Free Trial → See Plans & Pricing No credit card required to start