Final answer:
The blood is drawn from the canine lateral saphenous vein while the dog is in lateral recumbency, with the procedure involving manual occlusion of the vein; unlike human blood draws that may use a sphygmomanometer, manual occlusion is generally sufficient in canines.
Step-by-step explanation:
The proper procedure for assisting in the drawing of blood from a canine patient's lateral saphenous vein involves placing the dog in lateral recumbency. This vein is located on the lateral surface of the leg, and it plays a critical role in draining blood from the superficial regions of the lower leg and foot, leading to the popliteal vein. During the blood draw procedure, one must occlude the vein with their hand to ensure that the vein is prominent and easier to access. In clinical practice, this is somewhat similar to the use of a sphygmomanometer blood pressure cuff on a human's arm, where the cuff is inflated to temporarily cut off blood flow, aiding in the identification of veins. However, a cuff is not commonly used for canine blood draws as manual occlusion is generally sufficient. It is important to note that while the median cubital vein is the most common site for drawing venous blood in humans, the lateral saphenous is preferred for canines. Additionally, like in humans where skeletal muscle contraction can aid venous blood flow via the skeletal muscle pump, proper handling and positioning of the canine patient can facilitate the drawing of blood.