Skipper has a sore paw. I have been inspecting it numerous times each day and I cannot see or feel any heat, inflammation, or swelling. He doesn't cringe or flinch during these examinations.

A few days ago I tackled all 8 dog's feet and however many dog claws that adds up to. I was very proud, because afterward their nails looked nicely short and rounded, no quicking. The next day I was playing with Skipper and I noticed blood on the floor, just a few little flecks. I realized it was coming from his left front paw, but I could not see the actual spot where the blood was oozing. He has a nail (his left hand forfinger) that gave him trouble before, so I gave it an extra filing to make sure it wasn't rubbing his foot.

Since then, when he first gets up from a long sleep, he hobbles around with his foot right up in the air, not putting any pressure on it. After a few minutes he is limping on it, and after awhile he is running and jumping as per his usual self.

He limped on this paw intermittently before and I took him to the vet and had it examined. The vet manipulated his joints and trimmed his nails. He couldn't find anything obviously wrong. Possibly arthritis. The nail on Skipper's left hand forfinger actually cut into his foot after the vet trimmed it, that was how I learned to be extra careful with that nail.

Up until this recent situation, Skipper hasn't limped perceptibly for a long time. I'm wondering if I should try soaking it in warm salty water?

There are many things.
The ground where you are now is it harder, softer, more coarse (sand ans gravel). Some dog get irritation to their pads and it can be really hard to find where the blood comes from. For that type of problems I use an antibiotic ointment and boots.

If he is lame/sore from the change in temperature. Cold and humid sure can make artritis flare up.

If you can find what is the cause then treament is easy. If you can't maybe wait a few days with lots of rest