http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CE8QFjAA&url=http%3A%2F%2Fwww.fws.gov%2Fsachuestpoint%2Fimages%2FNews%2FDeptofWildlifeTips-ExclusionsDeterrentsandRepellents0110.pdf&ei=GeLMUO7uCoXM9gSP8YBo&usg=AFQjCNGlioRtEFNez4vUB3oIs7HUVJzf3Q&sig2=frRkh3wYz0Ws7AzuvsYY6A&bvm=bv.1355325884,d.eWU
the link is a pdf that may or may not open for you. Here is a excerpt
The following items may help repel or deter coyotes away from your yard. Some items are squirted through
squirt bottles or placed on rags and placed in the area(s) you want the animal(s) repelled from. Others are just
placed out periodically if coyotes begin to frequent an area.
Radios, strobe lights, sirens or odor deterrents may help deter the presence of coyotes:
Electronic Guard EG consists of strobe lights and sirens run by a timer. Produced by the United States
Department of Agriculture Wildlife Research Center to protect sheep from coyote predation.
http://www.aphis.usda.gov/lpa/pubs/fsheet_faq_notice/fs_wseguard.html
Human scent (cologne/perfume). Must be re-applied over time/after rain.
The Guardian TM deterrent emits different noise frequencies to ward off unwanted wildlife.
http://www.pestrepellerultimate.com/guardian.htm
Ammonia-soaked rags or apply to an area with a squirt bottle. Must be re-applied
over time/after rain.
Motion lighting, strobe lighting, and blinking holiday lights.
http://icwdm.org/handbook/carnivor/coyotes.asp
otherwise, pepper spray. Works great on any canine from what I can find.