Comparative Physiology Lab

In my comparative physiology lab we conducted experiment with different types of animals.  One experiment was involved sedating a rat, disecting it while keeping it alive, severing the ends of it's intestines while keeping its circulatory system intact and flushing the intestine with a glucose solution. Basically after the experiment was done(i think about 20 min) we killed it with an overdose of sedative.  Then there was an experiment with mice and altering their normal diet to either high protein or high carbohydrate.  Basically both groups of mice lost a high percentage of their body weight rapidly causing us to halt the experiment. We found out later it is more cost effective for the university to buy new mice for each class instead of constantly keeping mice and nursing them back to health(rapidly fluctuating body mass is stressful and would probably skew results of any future experiments) so the mice were killed the day after the experiment was halted.  I'm a vegetarian to boot, not entirely because of the killing animals factor(I know I'm not saving any animals by not eating meat).  I might have been able to take another class to fulfill the requirement but this one fit into my schedule.  I've always felt bad about it.