Is there any detriment to shaving my cats?

They are both indoor cats with serious fur balls issues. Costello, in particular, is a constant groomer and she is losing weight since all she does is ‘toss’ fur balls. Abbott, on the other hand, ‘tosses’ food. Abbott is scheduled for an ultrasound tomorrow and Costello is not far behind, to see if they have blockages. They go to the vet regularly and are on low allergy food. While they are 10 yrs old, my vet said other than the constant vomiting, they are in excellent health—blood work and xrays we good (Abbott has arthritis in her hips but you wouldn’t know it). Any ideas if it would hurt them to shave them?