Need some help and advice....

I adopted a cat three months ago and he has been such a loving cat but two weeks ago he had become very lethargic, eating less, meowing before using the box but still peeing, not jumping, walking slowly and losing weight. My husband took him to the vet last week were they treated him for bladder crystals. I am still giving him meds twice a week for it but we see no improvement. It has been five days. Should I be concerned?

Yes, you should be worried. My cat got blocked several years ago and was in the hospital for several days. I am going to paste a reply I made in a similar thread. Please put your cat on high quality canned food when you can. Also, what medicine?, my cat didn't get any medicine. An antibiotic? The worst food for cats to be on is dry food, I learned that the hard way when he got blocked.

From another thread I posted in:

It's been several years now and he is fine and hasn't had any more problems, thankfully. My two main sources of help were Dr. Lisa Pierson and her website Catinfo and Dr. Elizabeth M. Hodgkins and her book Your Cat: Simple New Secrets to a Longer, Stronger Life. She writes that she puts most, if not all, of her patients with crystals on canned food. 

I first started giving him Fancy Feast Chicken Pate, however, I do not recommend feeding any food made by Purina, as all 6 of my cats began getting ill and REFUSED to eat the Friskies I had been giving them to try and save some money last October. I just don't trust Purina any more as I found tons of other people online whose pets had also gotten ill, some much worse than mine.

Right now, he mostly eats Triumph and Canidae (All Life Stages green has the most meat). I buy the large 13 oz cans online from Chewy, they come in a pack of 12-they have the BEST prices most of the time and the food comes in two days. I have also fed Natural Balance and Wellness canned. Also, it is recommended that cats with a history of crystals don't consume high amounts of fish.

Forgot to say, if he is blocked it is an emergency and he has to get to the vet ASAP, hope he's okay.

Can you call your vet to advise of no improvement? They may be able to advise you over the phone or may need to see your boy again. I do think a timely follow up of some sort is called for. It sounds as if the current treatment plan is not working.
When my female cat had urinary crystals, she was immediately put on an all canned diet (as previous poster mentioned...very important!) in addition to anti-inflammatories and pain meds. The canned food was prescription food with the purpose of disloving the crystals (I have since switched her to a non-perscription canned) and had to bring her back a week later for a follow up with the vet and a follow up urinalysis. Did your vet schedule these things as well?
Please call your vet (or an emergency vet) as soon as you can.

Thank you all that replied. Last evening I helped my little boy cross over the rainbow bridge. His condition worsened and my vet diagnosed him with wet FIP. I am devastated as I only adopted him three months ago and now have to worry about my other two cats. Sigh.

So sorry to read this news.  On behalf of the TCS Team, we offer our sincere condolences on the loss of your little one.  We'll close the thread now out of respect for your loss.  Please consider posting a tribute in our Crossing the Bridge forum.