Dermatophytosis (ringworm) is a superficial fungal infection of hair, skin and occasionally claws. In dogs it is less common than its reputation suggests, accounting for under 4% of skin disease, and bacterial folliculitis often looks just like it. It matters because it is contagious to other animals and to people, and because getting the diagnosis right depends on understanding what each test can and cannot show.
Key facts
Dermatophytosis at a glance- Species and system: dogs (and cats); hair follicles, stratum corneum and claws.
- Cause: keratinophilic fungi, mainly Microsporum canis (from cats), Nannizzia gypsea (formerly Microsporum gypseum, from soil) and Trichophyton mentagrophytes (from rodents and other animals).
- Classic presentation: patchy, circular alopecia with scale, crust and variable redness, often on the face and limbs of a young dog.
- Course: self-limiting in healthy animals over about 6–12 weeks; treated to shorten disease and limit spread.
- Diagnosis: no single gold standard; Wood's lamp and direct exam support, fungal culture or PCR confirms.
- Zoonotic: yes; human infection is usually mild and easily treated.
What's inside
12 sections in the full guide- Key facts
- How the NAVLE tests this
- Cause and pathophysiology
- Clinical signs
- Diagnosis
- Differential diagnoses
- Treatment and management
- Prevention, control and public health
- Prognosis
- Quick review
- Test yourself
- References
The full guide also has 6 tables, 3 figures, 3 self-test questions and 13 references, available to NAVLE members.
Read the full study guide
The full guide is part of every NAVLE plan, with diagnosis and treatment tables, figures, a quick review and self-test questions. Start a free trial to try the question bank, or log in if you are already a member.