The passage of drugs into horse saliva and the suitability of saliva for pre-race testing.

Figure la shows how a saliva sample is taken at the racecourse by swabbing out the horse's mouth with a gauze pad held in forceps. This usually only produces 2 to 3ml of saliva. However, work at these laboratories has been facilitated by use of ponies with explanted parotid papillae. The papilla is the site of the opening of the parotid salivary duct on the inside of the cheek, and in each of these ponies a surgical operation has been performed which brings one papilla through to the outside of the cheek, so that pure parotid saliva can easily be collected.