Rats tail changing colours.

Question
My friend has a white rat that is approximatly 4-5 months old.. His tail has recently changed from pink to like a gross brownish greyish colour...She's very worried that there might be something wrong. I had read that it could possibly just be stress or lonliness or "maturing"....should she be concerned about it or is it just a normal thing? thanks for your time.

Answer
 What kind of bedding is your friend using?  Some beddings such as shredded newspaper and recycled paper pellets such as Yesterday's News can cause the tail to become greyish.  Have your friend try to wash his tail, using a soft toothbrush with warm water and pet or baby shampoo or even dish soap to see if any of the discoloration comes off.  If it is simply dirt or stain from the bedding it should come off or lighten at least a little bit.  Tails are notorious for getting dirty and can be difficult to clean.

 If there was a medical problem you would notice the tail hanging limply, being dragged and unable to be moved past a certain point, a blue discoloration, and the rat would likely be acting painful or otherwise ill.  It is very likely just dirt which will probably wash off.  If the tail doesn't come clean but the rat is still acting fine otherwise I wouldn't worry about it.  Some rats just have dirty tails and the little scales can trap dirt and even scrubbing will fail to clean them.

 Hope that helps!