Ok, so the daycare i worked at had five classrooms. The 3 year olds had a child with a case of ringworm. Isolated case.
Suddenly a child in the 5 year old classroom had it but he had no contact with the 3 year old and we thoroghly bleach everything. Turns out his sister CARRIED it with no actual infection to him.
I think you can have ringworm and it be like...dormant. That's proably how Kyro's cat ended up with it.