Ringworm (dermatophytosis) is a common and highly contagious fungal infection in cats. Prompt diagnosis and treatment reduces suffering and prevents spread to humans and other animals.
Active ringworm causes itching, discomfort, and secondary skin damage from scratching. Severe or widespread infections can cause significant skin inflammation and pain. The welfare concern is amplified in shelter settings where ringworm spreads rapidly and has historically led to mass euthanasia of entire cat populations — a disproportionate response to a treatable infection. Modern shelter medicine protocols, including systematic antifungal treatment and environmental decontamination, have dramatically reduced ringworm-related euthanasia in progressive shelters. For pet cats, topical antifungal treatment combined with systemic medication for widespread cases usually resolves infection within 4-8 weeks. Owner compliance with full treatment courses is essential — premature discontinuation leads to recurrence.