VS can also be spread through contaminated equipment. Timoney explains that some diseases spread several ways. In the case of ringworm, it would be contact or indirect contact. An inanimate object that passes a disease is called a fomite. Fomites for ringworm can be brushes, blankets and tack, as well as fence posts.
Ringworm can also come from rats and mice.
Leptospirosis, on the other hand, transmits through water. Leptospires are water-based organisms that are adapted to live in the liquid phase. So they don't survive very long once they dry. Horses pick up this disease from places such as a pond contaminated with the urine from infected animals. You've got a zoospore that gets into little rain droplets on leaves on branches.