Answered By Pt Sri Pranesh Achar (Ananda Rangan)
General
We should change the sacred thread when it becomes old, dirty, worn out, or broken. This is said in the shloka “Upaveetam bhinna tantum, jeernam, kashmala dooshitam.”
We should also change the sacred thread in the following situations:
After visiting a house of death or attending funeral rites
After touching a dead body
After touching a dog
After touching a woman during her menstrual period or speaking closely in that state
In all these cases, changing the sacred thread is required.
