Long time reader, but new poster. Please forgive my forum using inexperience! On Monday we brought our approx. 12 yr. old cat Kagemusha to the vet thinking he may have a blockage for incongruously not eating (he normally eats everything in sight!), overgrooming his stomach that a hairball seemed highly possible (he's never done that before either) and throwing up what he did eat outside the litter box. It was over the weekend and after he still had not eaten or drunk water and was lethargic I syringe gave him 2 tbs. water, some Nutri Cal and coaxed him to eat about 3/4 can Fancy Feast. We thought blockage for having a cat before who exhibited the same symptoms ending up in emergency because of it. The vet asked us the standard questions and brought him back to run xray, blood and urinalysis. They found no blockage or anything out of the ordinary on xray. He had no ketones in his urine, but she said his bg was 250. He was highly stressed at the time. In general he's had higher stress from us having a baby after a lifetime of child free home and in between this time two of our other cats passed away (one from suspected pancreatitis, the other (seperated from him) of complications from FeLv). Still, 250 is high and from our former blocked kitty having been diagnosed diabetic years prior we accepted the vets assesment Kagemusha is diabetic. We'd tested him a few years ago along with our other guy and his bg was always in perfect range, but understandably things could've changed. I didn't have test strips on hand to check him myself this time, so to err on the side of caution decided to start him on lower dose of .25 Lantus every 12 hours instead of their recommended 1 unit until I could check where he's at. We started him on Tuesday night and I stayed up with him to make sure he didn't go hypo. He didn't, but I did notice around the time it would be peaking he seemed more tired and at the 12 hour mark he seemed perkier which I found a bit alarming. 3 more doses in between then and this morning and it was the same. Today he perked up more and asked for his food at the usual times like he normally does. He's still not eating as much as he was before (usually 3 cans a day), but it seems understandable from feeling ill. His energy level is very low. Tonight we got the new Relion glucometer and test strips, so after eating his dinner and before giving him his shot I tested and it came back with 68!?! Feeling doubtful I did a couple more and it was still 68. I did not give him the insulin. I'm going to test him again at different hours to see how it fluctuates, but wanted to ask what anyone here thinks … could he have been incorrectly diagnosed?! Is it possible his numbers at the vet were wrong from illness or stress? Could the high amount of glucose in the Nutri Cal cause his numbers to be that high? Am I mistaken in thinking there's no possible way Lantus can act that quickly? I'm a bit distressed he could've been spending the past couple days being hypo from the insulin.