In addition I like to bind my pups cock and balls as to keep it nice and hard, but without the possibility of wanking off. This is useful for keeping him on heat for some of his harder training where he maybe allowed to stroke his doggy cock but that is as far as it goes. This is often used in conjunction with fist mitts/dog paws so that the animal cannot get access to free himself.
One method is to use a fine leather lace (1mm by 2mm in diameter). The first is knot is at the base of the cock (where the cock ring normally goes). This need not be too tight, the next then goes around just the cock with a knot at the top of the balls/base of the cock. Keeping the two laces together thread then under the lace that circles the bottom of the balls (where a gauche might go. With care pull the lace through as this will cause friction burns on the skin otherwise. Pull this tight enough to cause the balls to be separated.
Then tie a knot in the front in the front and repeat with another knot at the base of the cock and top of the balls. The lace can then be passed down between the separated balls looping around to the front where it can be tied off. This allows the slaves balls to be further separated. For short periods you might like a figure of 8 binding around the balls. But the tighter it is the less time it can stay on. the balls of some slaves can swell quickly and cause real pain and you will need to be able to remove the binding easily if needed.
This example assumes that the slaves cock has a PA in it and that his foreskin is pulled back or that he is cut.
Thread the lace through the PA and tie a knot in the front of the cock head, so that there is a loop the encircles the crown of the cock head. Ensure that you do not trap and of the skin in the bindings. Then with the lace, zig-zag the binding down the cock with the know alternating between front and back. The spacing is about 25mm to an inch apart, then secure the ends of the lacing into the binding of the balls.
This results in an effective cock ring keeping the dogs cock nice and hard, with a nice feeling of the shaft being gripped. But preventing the cock being wanked (in a fist) as there is no possibility of skin movement. Because it provides a nice grip when the cock is anything but soft the slave is nicely aroused. The PA ensures that the bindings do not slip off, and when the cock is very hard the PA is nicely tugged hard, as the erection increases.
The cock can be safely covered with a condom and if the slave is required to fuck another slave it will be a particularly hard fuck leaving the other slave sore.
This has to be done with some care as the lace can 'stick' to the skin a little. Further there might be some swelling, so always keep an eye on the slave to ensure that he is find. If it is done too tight 'blisters' may form (which will go down in time). This is where there has been some pinching or abrasion. If there is to be movement you might want to use some lube.
If the cock is free between the animals legs it can be left dry.