The diagnostic testing may not be complete so that underlying medical problems are still detected — for example, a cat that sprayed urine with blood found to have bladder stones ultrasonographically that radiography did not detect, or an older cat having hyperthyroidism causing fecal soiling. (tampabayvets.net)
Occasionally, a cat that is suspected of having hyperthyroidism has a TT4 level within the upper range of normal. (lienanimal.com)
Teenagers who have hyperthyroidism may or may not need to take medications for the rest of their lives to keep the thyroid gland stabilized. (howtoadult.com)