You can see a photo of a typical horse in diaper here: http://blog.peta.org/archives/Carriage_Horse_New_York.jpg
The manure is removed from these diapers at the stables and mixed with sawdust and hay. Gardeners are invited to haul it away free.
Today was our day. We rented a truck from PhillyCarShare, got our buckets and shovels and did our version of fill-her-up. Most of it will go on the garden for the winter. But some of it is going into the worm bin. The worms get a real feast in the winter because they get all my kitchen scraps. In the summer, most of the scraps go to the regular garden compost bin.
While my husband, the alien, and I were filling our buckets, a neighbor walked by and asked, "What are you doing?" After we explained, he asked, "What do they charge?"
"Charge?" asked my husband. "We're providing free manure removal service."
The neighbor walked on, shaking his head.