19 year old boa constrictor

I have a 19 years old, 9 foot 23 lb boa constrictor that after over a decade of not refusing food, recently stoped eating. She has always been a rabid eater. She has been tested for ibd, and had a full blood panel with no abnormalities. My vet wants to do an ultrasound and xray , at what point is it worth realizing that she’s old . Am I way off here?

Hello - a well-looked after Boa constrictor can live for up to 30 years in captivity.  The average is pulled down because husbandry is generally quite poor.  There are many things that can cause anorexia in a snake, including factors related to housing and an impending skin-shed; an informed, careful history would need to be taken in order to start to identify the problem.  Therefore, we would recommend actively seeking out a reptile specialist vet.  Vets are generally very practical people and while some owners worry about asking practical questions,  there is likely no need.  Questions such as, 'What is the on the list of possibilities for my snake (based on an examination and full history)', 'Are some much more likely than others?' and 'Which of these possibilities do you think you might be able to do something about?'  'How can you discriminate between them?'  'What sort of cost could you for-see?'  would be a good line of questioning.