Tommy, a 4-year old male neutered domestic short hair, presents to you for frequent urination. Urinalysis reveals 4+ struvite crystals. An abdominal radiograph shows a 1 cm round calculus in the bladder. Tommy does not have a urethral blockage, and urine culture is negative. The owner says surgery to remove this stone is not an option due to finances. Which of the following would be the most important treatment for Tommy？
Tommy是一只4岁雄性去势的短毛猫，排尿频率增加。 尿液检查发现有鸟粪石结晶++++。 腹部X光片显示膀胱中有直径1厘米的圆形结石。 Tommy没有尿道堵塞，尿液细菌培养也是阴性。 畜主表示由于费用过高，并不想进行手术取石。那么对Tommy来说，以下哪项是最重要的治疗？