So, I told you that I have an odd job.
Though I’m a veterinarian, I work at a large human medical center, behind the scenes, in the animal laboratories. Few of my friends are scientists or medical people, so they don’t always understand how a human medical center could keep a vet employed ---- or a team of 6 vets and a dozen veterinary technicians. After all, if the point is to make animals sick so you can study their diseases, wouldn’t a vet be beside the point?
Science lab needs to care about animal health and welfare, for several overlapping reasons. All of these I’ll talk more about over the life of this blog.
1. Healthy animals make better research subjects. Most medical research does not call for making animals sick. Even the research that does can be confounded by infections animals might naturally carry, if we vets were not so vigilant. One classic example: the US National Cancer Institute presently says there is “no clear evidence that [the artificial sweetener] saccharin causes cancer in humans.”1 But early suspicions in the 1970s that saccharin might cause bladder cancer were complicated by concurrent infection with the rat bladder threadworm, Trichosomoides crassicauda. Nowadays, vets and scientists would not tolerate this infection in a colony of laboratory rats, not because of the minor illness it could cause, but because of how it could complicate any examination of the animals. This is just one of many examples of how animal disease can undermine animal experiments.
2. Happy animals make better research subjects. Trying to study the immune system? Digestion and nutrition? Cancer? Behavior? Just as in humans, stress in mice and other animals depresses immunity, slows digestive function, affects cancer rates for better or worse, and knocks behavior in all sorts of directions.
3. It’s the law. In the US, for example, we have two major laws at the federal level that establish animal welfare standards for laboratory animals. The Animal Welfare Act (first passed in 1966) covers a limited number of species (including all the most numerous: the mice, rats, fish, frogs, fruit flies). The Health Research Act of 1985 covers more species (not the fruit flies) though only in places that receive federal research money. Together, those two laws cover millions of lab animals, and require vet care, use of painkillers for most painful projects, and an oversight committee with community representation (an “IACUC”). I’ll have lots to say about the strengths and weaknesses of these laws.
4. Are you sitting down? Believe it or not, most scientists I know really do care about their animals’ health and welfare. They want their mice or their monkeys well fed and cared for. They want a vet if the animal looks sick. They want training on how to do anesthesia and surgery, and how to euthanize the animals correctly when the time comes.
But it’s not easy --- if you want to model human disease, to understand how it works, to try out treatment possibilities, you’ll often want to replicate some part of that disease in your animals. But how do you re-create a human disease in animals without making them sick? In my next posting, I’ll look at glioblastoma (a brain cancer) as a case study of that line we walk.
1. To read more about saccharin, bladder worms and rats, look at these references. Perhaps you’ll find them reassuring. Even without the worm, male rats remain susceptible to bladder tumors when they consume saccharin, in a way that people do not seem to be, thus the decision to delist saccharin from the NIH list of “reasonably anticipated carcinogens.”