Why does the dog react in the manner that it does in "There will Come Soft Rains?"

In "There Will Come Soft Rains," the dog acts upon the conditioning that he has received. 

When the poor dog returns to the house, after having been subjected to radiation, he whines at the door which is made to respond to sound. Then, he searches the house for the occupants, but they are not in any of the rooms that they occupy. He, then, sniffs the air and smells the pancakes. so, he runs to the kitchen where the occupants usually convene to eat.

The dog frothed at the mouth, ...It ran in circles, biting at its tail, spun in a frenzy, and died.

The poor dog has suffered from radiation and its nervous system has been attacked; therefore, he acts with frenzied movements. Not unlike the animals on the nursery walls that glow, the poor dog is close to glowing, too, as he has been subjected to the nuclear explosion that has plastered the people against the wall in silhouette.