The phrase "large vein" refers to a blood vessel in our body that carries blood from our organs and tissues back to the heart. It is bigger in size compared to other blood vessels in our body. Full definition
The pressure makes it difficult for the dog to breath and it can also compress larger veins in the abdomen which can prevent blood from returning to the heart. (halifaxveterinaryhospitalinc.com)
Sleeping on your back, the weight of the uterus can cause large veins to compress, reducing the amount of blood flow. (cozybump.com)
As these patients start having to access larger veins, they become more prone to these types of infections.» (sciencedaily.com)