First I have to say that after reading of your latest incident and of similar incidents, I realize that I’m really lucky in this regard. I run in a small park near my house. I see the same people all the time, and they move aside to let me by. Ninety percent of the dogs are leashed, and the ones that aren’t have always been really well-behaved. Before I moved here I ran in a large park in San Diego. That park had a leash free area for dogs to run free. I stayed away from that area and never had a problem with unleashed dogs.
I agree with the previous comment about working with a group to address this issue. If there’s a running club in that area, I think it would be worth your while to contact them. There’s definitely strength in numbers.
I know you’ve talked to animal control after previous attacks. Have you made any effort to talk to them at other times to try to get them (or park dept. or whoever has jurisdiction) to do any type of patrols and get irresponsible dog owners cited. Hitting them in the pocketbook may be the only way to have an effect and waiting until after an attack is usually too late to find the offenders. Although thinking about it, you’ll probably get the line about no funding and only having enough manpower to respond to specific incidents…
For now I think the pepper spray may be your only defense.