I so know that feeling of being concerned about your baby and going through the trouble and worry and expense of getting them to the vet only to really have no answers.
Chin up! Glad the lumps went away from Taz. What kind of Science Diet food is it? Is there another brand that would offer comparable results that you would prefer to feed him? I know I didn't have good results with Science Diet Lite. Morgan gained weight every time he went in despite being on a strictly rationed diet! My other wonder is why if the blood work was done in March and the levels were up then, whey did they wait until now to change the food? Especially without another blood check. Strange. Hope you slept well!