As you may know, Stephen King has its own shared universe, bookwise, this sometimes leads to hilarious implications, such as Pennywise's greatest enemy being the Space-turtle-Jesus. Given that, I wonder if there's a in-universe backstory behind the Pet Sematary and if yes, what it is.
The only tie-in with the Dark Tower universe that I've found that Stephen King acknowledged is the following:
Zelda Goldman (Rachel Creed’s sister) thought that Oz the Great and Terrible was a version of the Grim Reaper. Because of this, Oz the Great and Terrible becomes a symbol of death throughout PET SEMETARY. Roland, Eddie, Susannah and Jake visit a version of Oz’s Palace at the end of WIZARD AND GLASS.
And frankly, that's pretty dang tenuous to me unless that Oz and the one mentioned by Zelda are indicated to be the same.
There is a likely side-reference to Cujo.
“Rabies,” Crandall said. “Lot of rabies in Maine now. There was a big old St. Bernard went rabid downstate a couple of years ago and killed four people. That was a hell of a thing. Dog hadn’t had his shots...