Are you sure it wasn't bitten off? 
Here are some links about Manx animals, including a link about the genetics of manx mice. They are poor criples and should never be bred.jujubee18 said:I have just recently acquired a tailless or short tailed mouse...Her tail is only about a cm long. What I am hoping is that I can breed her with my other dove and produce some tailless doves somewhere down the line, but I have a few questions. First of all is the tailless gene recessive? also If I am breeding two doves together what are some common unknown colors that may pop up?
For a mouse a tail is importantb for many reasons, eg for climbing/balance, heatregulation, showinmg emotionds to other mice, and so on. A mouse without tail is a poor criple, it does not matter at all, if it is serious ill, because the hips, spine and urinary tract are deformed in addition.jujubee18 said:I'm curious...If it happens that this is something that just popped up in his line, and isn't like breeding shortish tailed mice until their offspring end up with shorter tails and so on [which I understand would be really bad for their spine and hips] Will it still have the bad hips and spine? She looks like she is walking around like a normal mouse, and her spine looks smooth and not contorted at all.