health of my dwarf bunny

Question
My male dwarf bunny, who is about 1 and a half years old, just started peeing a red color. Could it be blood? I did some research and most of the answers said not to worry about it and that rabbits sometimes pee a red color. Some said it could be from carrots, too much beta carotene, stress, dehydration, undigested minerals, beetroot or cold weather. I haven't gave him carrots for about 3 weeks. I usually give him pellets and timothy hay. The weather is cold now, but I brought him inside to be warm for the winter. Could stress be the reason? Recently I lost one of my rabbits and maybe he misses him? Could you let me know if you have any different answers why his pee is red or if any of the above answers could be the reason? He seems to be hopping around, and acting totally normal. He has been peeing red for about 3 days. Could you also let me know what betacarotine and beetroot are?


Answer
First, beta carotene is a vitamin that is found in many fruits and vegetables.  It's found in colored vegetables like carrots, some lettuces, spinach, and others.  In people, it's thought of as very important to eat food that contain beta carotene.  I assume it has health benefits in rabbits also.

Beetroots are also known as beets, they're just a vegetable.  Rabbits shouldn't get very much or any beets because they're high in sugar.

I wouldn't expect stress or missing his friend to cause a change in urine color.  Usually stress or sadness/depression from the loss of a friend may cause problems that are seen as changes in poop size or consistency.

This article also mentions that this is seen often after the first cold snap.  It doesn't say why that would cause red urine.  But maybe some info in the article will help:
http://www.rabbit.org/journal/3-1/red-urine.html

If the urine is red and has red streaks or flakes, or if it really looks more like blood than urine, a trip to the vet is in order.  

Also, has the urine habits changed in your bunny?  A lot of times, a health problem related to urine can be seen in a change in litter box habits, straining to urinate, or an increase in urination.

Otherwise, if you don't see any other signs of a health problem, you could wait a little bit longer and see if the color goes back to normal.