Dealing with a big horde of zombie dogs after they spawn can be a huge pain for most people, even I had issues with that too, but this can be easily overcome by keeping distance from 'em and fire for weak points. If one of the two options fail, I would highly suggest staying somewhere high ground, like the upper floor in the pyramid or down the sewer tunnel in the cave route (which is more safer for me in the higher waves).

As for how constantly they spawn, I think that's intentional in most cases because as you're progressing waves, it gets harder from there, so I recommend getting a weapon of your choice, unlock the Nether room, beat the golem by kiting it in the village (you might need to leave one zombie alive for this to work), and pack a punch that weapon you're gonna use in the long run (trust me, a pack a punched weapon is better than nothing).

For potions, I highly recommend getting the Health boost ASAP in the early waves first, just to be on the safe side, and as you're going for the speed boost, there is one in the sewer zone, which is very far, unless you're going for the cave route, then you're good to go.

We made it to the end and took the house from the big boy but the dogs were still a real big challenge. It was only til we hit the sewers is when everything became cheese and we found it was kinda ridiculous that the stamin-up is all the way in the sewers. It really should be closer up to the surface like somewhat past the village like the jug is somewhat past the pyramid. After we got stamin-up the dogs were hardly ever a problem.

I guess moving the speed potion somewhere convenient is a good idea, since higher waves mean faster and tankier zombies can be overwhelming to some players.

Pack a punched weapon are very powerful against dogs if that helps, and thanks for your suggestion, I will move the stamina potion to another location

Yeah, Dogs are fast but also you should use good equipment like for example:
LMG (Pack a punched/ Normal)
T3 Sword (AKA. Ancient Sword, only if you have donated for T3 and above)
Contributor sword (Can only be given from T2 People and above, i also give free swords helping others)
Saiga 12 (Pack a punched/ Normal)
Any sniper (can be ww2 hunting rifles, Pack a punched)
Assault rifle (Pack a punched/ Normal)
Rocket Launcher (any of them, Pack a punched, For rounds 25 and above is not that useful, and beware shooting to close because splash damage).