Not only have I had lots of monitors, but still have lots now, and no, none have broken their tails. Of course, some have but chewed off by various creatures.
If I were you, I could consider what I said. Losing tails is based on stress. The tail tip, dies first then fall off.
If you hang around here for a little while, you will hear stories of monitors tails turning black, then falling off. This will be blamed on all sorts of things from, It must have hit it on something, OR it must have been too dry and the stuck shed made the tail fall off, etc, etc.
IF you continue to follow the stories of these monitors. Well, that normally doesn't happen, as they normally die and the owners do not come back.
Back to the point, no sir, I have never seen a monitor wack its tail and have it fall off. Not in captivity or in nature, and yes I have seen lots and lots in nature.
The concern here is you, why do you question me, and not question yourself. You do understand, your the one with the problem, not me, I only offer help. If you do not want the help, then great. But I am telling you the truth. FR
