Final answer:
Veins commonly used in dogs for venous access are the cephalic, lateral saphenous, medial saphenous, and jugular veins. The subclavian vein, which is a typically inaccessible area in dogs and thus not common for use, is the vein in question.
Step-by-step explanation:
The question posed concerns which vein is not commonly used for venous access in dogs. In veterinary medicine, the commonly used veins for intravenous access or blood collection in dogs are the cephalic vein, the lateral saphenous vein, the medial saphenous vein, and the jugular vein. These veins are typically chosen for their accessibility and the ability to safely obtain blood samples or place intravenous catheters.
Based on the information provided and general veterinary practice, the vein not listed and hence not common to use in dogs would be the subclavian vein, which is also not mentioned in the context of common venous access points in dogs. The subclavian vein is located beneath the clavicle in humans, and though dogs do not have an exact structural equivalent of the human clavicle, they have an area referred to as the shoulder where the subclavian vein would theoretically run. However, due to its location and the availability of more easily accessible veins, the subclavian vein is not a standard site for vascular access in dogs.