Since they are mainly looking at kidney function, they may be able to assess her through urine sampling rather than blood (much easier on her!) One of my pigs is on long-term suppressive antibiotic therapy and is tested annually for creatinine and kidney function. In her case, her quality of life is better on the antibiotics than it would be off (she has chronic UTIs and takes a continual low dose to reduce the bacterial load in the bladder to head off as many infections as possible.) I was concerned about the effects, but she has been on antibiotics for about 3 years and is still doing fine at age 4.5 years. I believe it's more of a precaution than anything else, and of course you have to weigh quality of life against the potential of side effects from the meds. I know for Sundae my feeling is that it's better that she have fewer years with good quality of life than more years with chronic infection and discomfort. Of course, I would prefer more years with good quality, and so far it's working well for her!