To be clear from the outset a tourniquet is dangerous and should never be used unless the injury is located on the tail or a limb and the dog would otherwise die.
A DIY tourniquet can me made from a two inch or wider piece of cloth and wrapped twice around the limb then knotted. A short stick or something similar ,(perhaps a pen or wooden spoon handle), should also be tied into the knot.
The stick is used to tighten the tourniquet until the bleeding stops. Tien tie the stick to secure it in place.
Write down the time ….. do not rely on your memory, you will have other things on your mind!.
You need to release the tourniquet very twenty minutes for fifteen or twenty seconds before tying it down again.
IMPORTANT – A tourniquet should only be deployed as a last-ditch effort because its use is highly likely to result in disability or amputation of the limb.