Dog sprayed by a skunk?
Dogs love to chase small animals. It's just their nature. To prevent encounters with nocturnal wildlife, here is a simple tip: Before letting your dog out at night, get into the noise and 5 second wait rule. This means, clap your hands a few times, then wait 5 seconds before letting your dog out at night. Wildlife smell dog in the yard, and don't want to be chased, and potentially attacked by a dog. Give them a few seconds to get out of your yard before letting your dog out, and all should be well.
A skunk's only defense it to spray when physically attacked. Dogs normally "get it" right in the face, indicating that the skunk was in imminent danger of getting attacked. These shy animals make divots under all of our fences to gain access to a 2-5 mile territory which they patrol at night for rodents and snails. It may take them a few seconds to get to the hole in the fence to get out. Give them that chance and they will. Turning on a light is not sufficient notice because skunks don't see well, but their hearing is acute. Also, motion detection lights are so common that this does not signify danger.
Recipe for "skunked dogs": make a solution 8 oz. hydrogen peroxide + 1/8 c. arm and hammer baking soda + 1 t. dish soap. With a wash cloth, apply this to the affected area, avoiding the eyes. Rinse in 15 minutes or so, or leave on.
This tip will also protect opossums who are frequently mauled by dogs, as their only defense when attacked by a dog who comes flying out a door at night, is to play dead. Raccoons are total athletes who can take a running leap at a fence and get up and over before a dog can reach them, if a fence is nearby. If a mother has young with her who are not able to climb quickly, the 5 second rule should at least give her time to get them to cover, under a deck for example, until the danger has passed. Shining a flash light out into the yard after you clap may allow you to see if the coast is clear.