Dead Dog/Alive Dog? --Spoilers

[Guest7]

So I have to kill 1st dog all over? (because I got that key from the office after I killed the 1st dog).
And the that door in north-central area has been unlocked for some time.

Looks like I must of done things out of order. Now if I kill 1st dog again, and keep north-central door open, no more dogs?

Most important: How do I get more dynamite?

Thank you very much for your help.