Horse shit makes them blow up. There is a cat on the out door forum "Mantoid" who is doing a green house in these layer beds that end up being 50% horse 50% green waste compost and he killed too. Makes me want to find some year+ old horse manure that is dry for my beds..
the acre on the other side of the fence from me is an enclosure for horses. They horses are only there for May and June while the grass gets taller in the neighbors pasture. So the manure is a good year old by this time of year. When it rains, the runoff floods over my whole garden spreading a compost tea. I can also mine aged manure from a couple of places along the fenceline and grab as much as i want from the piles in their pasture. We used it to build the soil in our veggie garden the first year here, but maybe I'll use it a bit more of it on the ganja this year.
I have to agree horse shit kicks ass as a soil amendment or as a compost tea, I have used a big bucket filled with horseshit and rainwater with much success.