What is this blister type thing on my dogs paw?

This appears to be a Histiocytoma (aka a Button Tumor). They are not a big deal, and usually resolve on their own. It is still a good idea to get to your vet to have it looked at. If it appears to be growing rapidly, or if it becomes more ulcerated, call the vet back and tell them. They will more than likely work you in faster if it is changing. Good luck.

Find a new vet, a dog with an issue like this and they can't see for a week, bad vet.

My guess is a boil, if you won't find a better vet, try white toothpaste and wrap, so the dog does not like off. Should form a head with in 12 hours.

Me I'd call the vet say "something is wrong with my dog, I need an er appointment" if they don't get you an appointment in 12 hours, start calling around.

My vet is a Banfield vet (yea I know most of them are not good, Dr. R is the best for small dogs). My dogs are sick, "when can you be here, it might be a wait, be we will get them in" If that isn't your vets attitude look for a new vet.

I agree, it could be a hystiocytoma, but it could also be a mast cell tumor (Mastocytoma) or something else entirely. Don't cancel your Vet appt., they may want to aspirate the lump to see what it is.

You might want to ask your Vet to trim your dogs nails, they are incredibly long. It's a grooming responsibility that has to be done. When your dog walks with nails that are too long, it increases the amount of pressure on your dogs toes (painful). The nails could crack and break because they are long, which could lead to infection and Vet bills. If you don't want to ask your Vet, you could take your dog to a groomer to have it done (about $10), or do it yourself. http://www.aspca.org/Pet-care/virtual-pet-behavior...

If you don't trim them, the 'quick' grows further down the nail and you won't be able to cut them much, resulting in painful feet for you dog.