1# Ball Python do not brumate

2# Fast can last up to a year

3# The fact that you lowered the temps is a contributing factor to your female not eating.

4# There is no specific acceptable weight loss it is a case by case and has to do more with the overall look of the animal then the weight itself, animal fasting 6 months or a year actually hardly lose any weight.

5# A vet is not necessary, in many case they do not really understand BP behaviour and/or metabolism and see problem where there is none.

6# Make sure your husbandry is optimal, if your female is not breeding there is no reason to lower your temps, ideally you want to provide temps of 76/78 and 86/88. You also want to make sure to provide proper humidity, adequate enclosure size and proper hides.

7# Alternative prey is never a solution the solution is optimal husbandry and PATIENCE.

I had females that size fasting for 6, 9 or even 12 months.