My 7 year old neutered, male cat is showing signs of constipation. A few days ago we were doing some construction in the house. We did clean up after ourselves constantly because we have 2 cats and 2 greyhounds. However, a day later, one of our cats threw up a ton of yuck. A few hours later I noticed that he was walking funny and cried when I went to touch his rear and stomach. He also stopped eating and slept under the bed which is unusual. We took him to the vet and all his blood work came back normal and the vet gave him a shot for nausea and to relax his stomach. That was 24 hours ago and he still has not eaten more than a tablespoon of canned food and a little water. He is also going to the litter box and squatting slightly and visibly "pushing", but only a little bit of runny, brown poop is coming out. Since the vet visit he has been a slightly more social, but I can't seem to get him to eat...tuna, milk, all flavors canned food, even the dog food that he usually loves to steal. Any ideas what could be wrong? Could he have a blockage of some sort? He has always been a picky eater and a skinny kitty, but this behavior came on suddenly. Any thoughts are appreciated! THANKS!