Can you tell me more about the diagnostics and antibiotics that Susie is taking? Did your vet do a urinalysis? Do you know the results? Was the urine cultured to see what bacteria were growing and then exposed to different antibiotic disks to see if there was a resistance? (This would be called a "culture & sensitivity"). Has she had urinary tract infections in the past? Were any x-rays taken to look for bladder stones?