My first thought was, "That's gross!" My second thought was, "I wonder if this happens to humans as well?"
Now you're thinking just like the scientists!
Nobody likes testing on animals. Unfortunately the experiments yield information that is important for our understanding of human development. The animal testing is a necessary evil. The long term goal is to develop sufficient technologies such that animal models can eventually be replaced with something else. But for studies like this one, I am not so certain that will happen any time soon.
I had to read a lot of ethics papers and philosophy given to me by my mentor Dr Wise who was lead researcher at the primate center at Emory University. There are a lot of ways to research and our ethics in science today as in the past are pretty much non existent. I mean there are a lot of ways to get around ethics if you have the right kind of funding. There may be benefits but most of the time research is done for profit and control rather than for health and freedom. https://www.newscientist.com/article/mg23531331-500-the-ethics-issue-should-we-stop-doing-science/
So what? You're talking to someone who does research for profit. Your implication is that my (well technically not my specifically but people like me) underlying motivations are not to help people. To which I take offense. Whats wrong with profits AND making the world a better place?
Because I've worked with nurses who tried to get funding and grants for research to help children and family health, there was no profit for big companies involved and no grants were given. This happens all the time and you know it.
I know the dark underbelly of research and grant world. Most of the funding for research comes from too large to fail corporations and government officials that depend on corporations to give them a job or fund their campaign running for office. The world of research is one big circle jerk.
You are the one that chooses to be offended or not offended...that is called true freedom. You have a choice...