CactiGuide.com

Hi, please can you help?
I have a euphorbia that I've had for over 10 years and he has been the picture of health. He is an indoor plant in London. Recently I have noticed a few changes and have searched the web, but don't feel confident about what the actual problem is and how to address it.
1) the base has brown ring marks, is this normal?
2)noticed today that one of the arms has turned brown and is slightly softer - soft carrot not squidgy tomato! Do I remove? Or can it be resolved.
I posted this on the cactus board, and they gave me advice, but suggested I check with you all first before proceeding with hacking off limbs!
Thanks so much in advance.
Sue

Hack that off if it's soft. Also check the base of the plant too see if its' soft too. Also hack off a healthy limb and plant it, so you have a back up just in case the larger plant is dying. Also don't forget to wear gloves and perhaps eye protection.

Thanks x