[SPOILER] Dogs get revived + question

[blackdawg47]

When I encountered the first dog, when you first descend into the mine, I killed it with the hammer. It was 100% dead because the music stopped and there were no more dog growls. So, I could go to the storage room without having to avoid anything. When I unlocked the door at the middle of the map, however, Philip says he should barricade it so the dog won't be able to get in. But I killed the dog! Hah, I don't need any barricade - bullsh*t! The dog just popped in as if I never killed it. Now that's very unrealistic, especially for the easy difficulty. I think dogs are respawned everytime you leave and reenter an area...

And my question is: considering the fact that Philip was trapped in the mine for more than a year, what did he eat and drink? He just had a backpack...not enough room for a whole year's meal. And even if we consider he ate 24-hour ration packs or beef jerkys, what about the water?