According to PETA, more than 100 million mice and rats are killed every year in US laboratories. Researchers subject these mice to all manner of tests ranging from inflicting wounds to shocking them with electricity to food deprivation. Millions of mice are genetically engineered to have various diseases or deformities, including cancer, Alzheimer’s, or other disorders such as blindness or a heart defect. These mice often live horrible lives of solitary confinement in cramped, dark cages stacked hundreds high before they are eventually put through a battery of intensive tests or simply killed so that scientists can see what exactly was going on inside.
Mouse models came into favor for various reasons. First, they are mammals, meaning that they share almost all of the same organs as humans and a vast portion of our genetic code. Second, they are relatively easy to breed; putting a male mouse and a female mouse of the right age at the right time will almost always result in numerous offspring, which is a key quality for labs that either go through a lot of mice or need to preserve certain generations for their genetic traits while crossbreeding. Third, they have short lifespans, meaning that progression of a disease can be seen relatively quickly and easily; if a lab used a dog model, for example, they might have to wait nine or ten years to analyze what the late stage of a disease looks like versus a couple months for a mouse. Finally, and perhaps most obviously, mice are small, easy to maintain, and don’t require much food or care, so it’s easy to raise large numbers of them for testing.
Despite how convenient it is to use mouse models, though, it is easy to rally for PETA and protest the use of innocent rodents just for scientific research. However, the reasons to use mouse and rat models are just as strong as the reasons not to. 1n 2012, more than 1.6 million people died from cancer. Alzheimer’s disease kills 500,000 people each year, and in 2014 will cost America $214 billion. Cancer and Alzheimer’s are two of the top-researched conditions in America and around the world, and the majority of labs conducting that research use mouse and rat models to study them. The mice are being subjected to pain and dying, sometimes in ways that can be considered inhumane, but they are giving their lives for a cause. With each mouse sacrificed and analyzed, scientists come one step closer to discovering the cure for cancer or a new treatment option for Parkinson’s disease. The road to a cure may be a long and bloody one, but are the lives of a few hundred mice really worth more than the life of a 9 year old child with leukemia?
I have been personally struggling with this issue for the past few months. The lab which I began working in is a neuroscience lab dedicated to working on treatments for Alzheimer’s disease, and it uses mouse models to analyze the role of certain genes and the viability of new treatments. During my second week at the lab, I witnessed the process of perfusion firsthand, a process which I have since performed myself. Without getting into too much detail, it basically involves opening the mouse’s chest while it’s still alive and anesthetized, injecting one area of the heart with a clear liquid and cutting a small hole in another area so that all of the blood flows out of the body and is replaced with the clear liquid. If the mouse doesn’t die during this procedure, it is killed afterwards and its brain is harvested with scissors and tweezers. The first time I saw this and the first time I did it, I almost wanted to throw up. What had been a scurrying, squeaking little rodent a few minutes ago was reduced to a bloody mess and a precious brain that contained the data we so desperately need to find a cure for this awful disease. It reminded me that everything comes at a cost, and the question of the value of life still haunts me every time I look at the mice.