I would suggest you use the handguns for bad dogs and the spray for 2 legged dogs.
I do like your choice of pistols.

Many dogs are not the least upset with bear spray. My little sharp-nosed springer was not fazed in the least by bear spray.
She snuffled right through the reddish/orange patch on the grass and even licked it, then carried on her way as if nothing untoward had happened.

About black bears, my older daughter returned to the tree planter camp at noon, to find a black bear eating a can of bear spray that was left on the table. The bear was sprayed after it punctured the can, from it's eyes to it's throat and it's mouth was orange was it lapped up the spray.

Not sure what this all means, but my springer and that bear did not mind it.