Ringworm, caused by a fungus not a worm, is the most common infectious skin disease in cats and a significant welfare concern in shelter and multi-cat settings.
Ringworm causes welfare concerns primarily through skin discomfort and itching, and through the treatment burden it places on affected cats. Active skin lesions are pruritic and uncomfortable, and cats may over-groom and cause secondary skin trauma. However, the largest welfare impact is often the management response: cats with ringworm in shelters may face isolation from social contact, and historically many shelters euthanized ringworm-positive cats due to management challenges. Evidence-based treatment protocols using antifungal shampoos and systemic medications combined with environmental decontamination allow most cats to be successfully treated and adopted. Ringworm should not be a death sentence for shelter cats.