As Rothschild explains between vivid close-ups of skunk-holes and their anal-scent glands, the fetor of the mammal’s spray is all a product of chemistry.
“The chemical makeup of the spray is different depending upon the species” of skunk, Rothschild notes, “but all of them contain special kinds of compounds called thiols.”
Thiols are essentially a compound of sulfur (which smells terrible) and hydrogen atoms bonded together -- it’s in these vengeful chemicals where the wrath of all skunks can be found. Per Rothschild, we learn that there’s actually three of these awful smelling compounds present in striped skunk spray, and two of them smell downright nasty. There’s also the Thioacetates -- three of which are found in striped skunk spray -- which smell bad when they interact with water, meaning that washing your dog after it's been sprayed can make it reek even worse.