I would regard a pack of dogs just as much of a threat as a gang of humans. Using a female decoy by coyotes is well known where my brother lives in Oregon, except here they kill pet dogs. Canines are intelligent creatures, they have to be in order to survive and be successful.
In a TEOTWAWKI scenario, I think it would be very wise to cater for this cos it will happen. Dogs will run in packs and they will end up tasting human flesh. Once that happens there will be no stopping their attempts if they're hungry.
Snaring sounds good, question is, John, do already have snares? If so, where did you get them from and can you post a link? I'd personally avoid poison, if we really do have a bad scenario played out and our food supplies are low then most would want to eat what they kill. Antifreeze sounds like it's very affective. Question is, if a dog dies from antifreeze, does that render it's meat useless? Guns from a safe vantage point sounds good but one day your ammo will run out so best to have something reusable?
Had a quick look on fleabay:
This small kit (too small for dogs?) was issued to American WW2 pilots
£16.90 delivered from Germany.
These are real coyote snares from the States
£32 delivered and you get a dozen.
From Amazon:
Here 10 x fox wires
£39.99 delivered