i have a 9 year old female cat. and its been peeing out of the litter box for almost 1 and a half year. in the beginning i didnt think anything of it. but recently its been doing it more and more. so i brought it to the vet and took a urine and blood test. result came out saying shes normal. then we did ultra sound to see if she have bladder infection. result came out saying its normal that no bladder mass or stone but the dorsal bladder is a slightly thickened which due to inflamation. vet gave medicine for my cat to eat for only a week. after a week if its still peeing outside the litter box. its been 4 days and its still peeing outside litter box. what is the problem here??

