Nothing to do with the Stephen King book, but a bit of purely local interest: today I visited the pet cemetery (largely a dog cemetery) on the Haldon Hills, near Exeter. It's mentioned in Chips Barber's book Around & About the Haldon Hills as being at grid ref SX877857 (that is, here on Google Maps). The closest landmark is Haldon Belvedere (aka Lawrence Castle), a prominent white folly at the northern end of the Haldons. It's just a few hundred yards from the road junction called Haldon Gate at the foot of the drive from the house. From the junction, follow the southward road signposted Chudleigh uphill through the woods towards Buller's Hill. At the top of this slope it bends sharply to the left; at this bend, on the left, is a small overgrown quarry with the cemetery in the woods adjacent.
The site is completely unofficial. There must at least 100 graves there; those with legible inscriptions all date from the 1980s and 1990s. The memorials vary from simple piled flints with homemade crosses to elaborate ones with brick borders and headstones. A lot of the accoutrements come from garden centres, but there are poignant personal touches: hand-painted signs showing a deal of work, and what appears to be dog's favourite shoe. Not much is known about the cemetery. Chips Barber, writing a couple of decades ago, said the site appeared to be unvisited, with the graves rather the worse for wear. He concluded that the owners must have died or moved away. Nothing much has changed.
A Western Morning News feature on July 3, 2001 reported that it was closed to further burials then by the landowner, the Forestry Commission, due to health concerns about animal disposal (this is a particular issue because the Haldon Forest is a Site of Special Scientific Interest for its fauna). Currently the cemetery is surrounded by a barbed wire fence with a locked gate, but a sign by the road gives contact details if anyone wants to tend an existing grave. You can, however, see many of the graves from the perimeter.
Addendum: I've put up a gallery of photos here.