Quote Originally Posted by nixer View Post
if you have any bad gene in your collection with inbreeding it will bring it out eventually it doesnt matter if only one mouse carried the gene or 5. i have seen ppl get it usually it results in deformed babies or offspring that seem fine but usually around weanling time they will start to run in circles stuff like that, but also if you get lab mice they could also carry something more serious such as cancer or any of the other genetic diseases
Running in circles is cause by an inner ear infection. It creates an unbalance in the equilibrium and is even more noticable when they are picked up. It has nothing to do with inbreeding. I'm not sure if it's caused by bacteria or just a weakened immune system.