Is my cat blocked?

Question
I'm very worried about my cat and I thank you in advance for any advice you can offer:

My 3-year old male cat has a large frame but is also overweight (18 pounds). He was blocked and hospitalized about 2 years ago. Since then, I feed him urinary S/O.

We just drove 20 hours over 2 days from Philadelphia to Miami. I gave him 1/4 tablet of Acepromazine each day to help him weather the trip. Along the way, we stayed overnight in a hotel and he ate and urinated. When we arrived, he was urinating as usual. However, a day later I saw him strain to pee in the litter box and only produce a few drops. After that, he urinated a good amount twice (I was not there to see whether he strained). He also defecated and his feces was hard and looked dried up.

In light of the stress of traveling and moving, and due to his history and the fact that he is male and quite large, I took him to the vet today. The vet felt his bladder and said he seemed fine. He gave him fluid under his skin in order to dilute the urine in his bladder, which he said will prevent crystals. My cat came home and I found some drops of pinkish fluid (perhaps slightly bloody urine) where he was sitting on the floor. The vet said it was okay, but that he should urinate within some hours.

Since then, he has been sleeping in his crate all day. He has come out a few times and nibbled on some of his food, but hasn't drank. He doesn't seem to be in pain and is even playful when I approach him with toys. He hasn't gone near his litter box at all. He feels a little "mushy" (as if the skin is soft and jiggly).

Should I be concerned that he is blocked since he hasn't peed and there were some drops of pink fluid? Perhaps he is over-hydrated? Is there anything I should be doing?

Answer
I doubt if he was over-hydrated but moving is very stressful for them. They usually sleep off stress if they can. You can tell if his bladder is full by laying him on his side and pressing gently on his bladder which you can find by pressing toward his spine and backwards towards the area where his legs meet up. It isn't hard to find a big, hard bladder.

If he feels fine, sort of soft down there, then I would chock up his sleepiness to the move and the ace. Ace is really hard on them also. Sometimes it takes days to get it out of the system. Once the stress of moving stops then the drug seems to take over again for a few days.

The pinkish fluid is bloody urine. He might have an irritated bladder from the stress also.

Just watch his closely for him straining. That will be the sign to watch for. Straining is a sign that the crystals are forming the pasty substance that plugs them up.

So keep the water in him and get him moving by playing with him and that will help also.
At least you have a vet now that you can take him to in case he does start straining more.