From a 1938 school book transcribed by the Dúchas Project, the digital archives of the National Folklore Project at UC Dublin:
Elf-shooting is a disease from which cows suffer. They are supposed to have been hit by a piece of flint thrown by a fairy.
The cow lies down moaning. Her eyes get swollen and water runs from her mouth.
A person who has the cure for "Elf shooting" is sent for. He proceeds to make the cure. He first measure her from the tail to between the horns using his arm from the elbow to tips of his fingers as a measure. He then cuts the tops of her horns and pieces from her cleats. He takes a sod from the roof of the byre, he lights it and when burning well it is passed three times round the cow's body. Then the pieces of horns and cleats with some hair from the cow are burned under her head the smoke going round her head. Soon she begins to get lively and in a short time is able to take a drink. Then she is all-right.
Seems legitimate. Gotta watch out for those flying faery flints.
Elf-Shooting [Urbal Scoil / Dúchas Project]