If this occurs more often than once, Sheriff sounds like a great plan. Meaning, maybe they had just escaped that day and now the owner will take extra caution to keep them contained. However, after that, I say call up the Sheriff and report it, every time it happens, if you don't want to answer 20 ?'s as they ask you all the details while you are trying to get to work, find out your local anonymous line and just call and report it with all the detail you think they need.
Air Zound Air Horn. 115 DB & Refillable with your bicycle pump = Win. Stops 'em in their Tracks.
Pepper Spray better than Mace, Pepper Spray = Immediate/difficulty with sight and smell, Mace = Pain, may take up to 15 mins to take effect.
Water bottle with Lemon &/or Lime Juice/Tabasco Sauce/etc. or a combo. Effectiveness against bipeds may be nominal, but for the dogs, it does have a wider spread/easier to hit their eyes. As for the biped attackers, except that the water bottle may not spray up very well, it's still a thought, just depends on the situation.
Here is a thought, never tried it, but I wonder if those pop rocks fireworks would work? You know those things you throw on cement and upon contact they snap/bang/tiny explosion? If you had a spare breast pocket or otherwise decent place to keep them, I would imagine grabbing a handful of those and tossing them in the dogs tracks/path would be a very humane way of getting them to end the chase. Plus this time of year I bet you could find some very cheaply. I found a route without dog problems, but if any of you find this to work well, please PM me and let me know.