I took a pup of mine to do some bite work and the chap (a Russian type bloke) receiving the bite had a puppy sleave on, when he presented his arm to the pup, my pup took hold, the man let out a argh! After I made my pup let go he checked his arm and said in a Russian type accent "if this dog bites you like this shit and piss comes out of here" pointing to his trouser leg , needless to say he went and got a more substantual sleave.