Cat lovers: PLEASE HELP - Sick cat, and what to do...

[jab105]

Currently we are caring for my husband's mothers cat...he is 18 years old...she was in Hurricane Ivan, and her home was destroyed, so we have been caring for the cat since September...

When we got him, he weighed about 12-13 pounds...he was fine through Chirstmas, about February...he started losing weight and fast...but he was still eating...we took him to the vet when he seemed tired one day (not acting like himself)...the next day, we took him to the vet (probably about 2 weeks after he seemed to be looking skinny)...and they diagnosed him with diabetes...he weighed 8 pounds...

So, we started him on insulin (a shot in the morning, and a shot at night), and he got better to an extent...but he still wasn't acting like himself...instead of coming out to be with us, he would sleep in the corner...

We then got him on fluids, a subcutaneous needle, about once a day...because he was dehydrated all the time...still, he always looked so sad...not himself...

Last weekend, we called in to get him another vial of insulin, but he didn't have any refills remaining, so they had to wait to call the vet to get him more, so even though he was still on his diabetes food, and getting his fluids, he missed a few shots (we got it first thing on Monday morning and gave it to him)...

He seemed back to where he was...ok, but not himself, still looked sad...then Thursday, we came home from work, and he was sprawled in the middle of the bedroom, and couldn't get up, could barely move at all...we rushed him to the vet, and his temperature was 96 (which is very low)...and he was yellow (ghandis- my spelling is wrong on this one)...they thought his liver wasnt working...and they felt a mass on his organs that could be a tumor...but his blood sugar was normal (which was good)...

So, they did blood work (biliruben was very high, liver was bad), and IV fluids all night...we told my husband's mother what was going on (this is her most beloved cat, and she has had a rough year anyways)...and she came down...

On Friday, he was better, temp was 101 - normal, he could walk a bit, still not eating very much (he weighs 7 pounds)...and my husbands mom came down...we took him to our regular vet, and she said to take him to the emergency vet...so they could monitor him during the weekend...cause he wasnt stable (still yellow)...

So, he had IV all night...today, she wanted to spend time with him...so we went to get him...his temperature was back down to 98 degrees...and we took him home, got him a heating pad, and some shrimp...he's so sad and tired, and still...he slept all day...and we are trying to decide what to do...

She lives 5 hours away, and the vet thinks that its his time (his organs are shutting down), that he maybe has a month left at the most...they also think he might have cancer (because of the rapid weight loss)...

So, we can either get an ultrasound on monday to see what the mass is and if he is stable get a biopsy...

or we can let him go...while she is here with him...

It is very hard, because she cant take him back with her (her home isnt fixed yet)...but, he might not make it that long anyways...and quality of life isnt so great right now...he sleeps, and get poked at all the time...

What are your thoughts? Should we find out about the cancer, and try to keep fighting all of his other problems with the fluids/insulin/ and now liver pills also...he's 18...

Its really hard (I've never had to deal with this before)...