What's "Normal" for an older cat??

I'm not sure if this is the right forum for this topic so I apologize ahead of time if it is. 

I've been dealing with a difficult situation recently. The family had an older cat (17.5 years old when he passed away). He was always fat but started to lose weight about a year and a half ago. I had been on my families case to take him to the vet (I don't live in the family home anymore) but they absolutely refused to using the excuse that being thin was 'normal' for an old cat and that it would be too stressful for him to go for a vet appointment given his age. I disagreed and regularly told them to get him checked out as I witnessed him continue to deteriorate. Their position was that he was eating and drinking and using the litter box regularly and essentially acting normal....yet continued to lose weight, to the point where he was not much more than skin, bones and fur. Their lack of interest in taking him to the vet lead to a number of heated arguments. Unfortunately no matter what I said they absolutely refused to have him seen. The poor old boy passed away recently from what my family calls 'old age', but what I believe was due to his continued deterioration to the point where his body could not sustain itself anymore. I'm disgusted beyond belief and feel they neglected him. Am I overreacting considering how old he was?

Contrary to what they seem to think, older cats should generally be seen twice per year by a vet, not just once.  It does sound to me that something was wrong with him and that he could have used a vet's help.

With that said, it does sound like the cat had a relatively long life, and I am not sure in a practical sense how productive it is/would be to continue to  hold a grudge against your family about this.  When you have your own cat, you will know better and be able to do better for him or her 

I have had two cats live to be 18 and 19 and they should be taken to see vet at least twice a year.  The reason this cat may have been going thin was possibly a thyroid problem which is very common in cats.  It happened to one of my elderly cats who was quite a "big boy" and started to lose weight.  He was given numerous blood tests to see if there was a reason for his weight loss and he was found to have this thyroid problem and was put on Vidalta tablets for the rest of his life.

These people do not sound very caring, if you have a pet you will at certain times have to take them to see the vet, if you don't want to pay vet fees best not to have a pet.

Some elderly cats simply do go thinner but if this was happening to one of my cats I would, at least take them to see a vet for a check up.

I actually do have a multi-cat household and do my best to see them cared for and regularly consult with a vet when required. One is actually sitting on my shoulder as I type  

It just blows me away that the family members flat out refused to seek veterinary care for their elderly cat who had been nothing but the sweetest love-bug to everyone all his life. I advised exactly what you mention teddytible, that he may have had a thyroid complaint that could easily be managed.....nope, no go. They weren't interested or even seemed to care and just keep saying old cats are 'thin". 

Is this a typical attitude? Can anything be done to educate people like this so they become more responsible as pet owners? My concern is that there are other cats in the home with another one getting up in age as well. She used to be overweight but I've noticed that she herself has lost weight. I'd say she's getting down to a healthy weight now, but am concerned about the weight lose in the first place. I've actually been considering cat-napping her to go for a vet check-up to see if anything is wrong.

Older cats need higher amounts of protein to prevent muscle wasting. Unfortunately, many commercial cats foods, especially dry foods, do not meet those protein requirements which is where I think people get this idea that older cats are thin. Kudos to you for trying to educate your family. Here is a really good article written by the foremost vet on hyperthyroidism that explains why.

http://endocrinevet.blogspot.com/2011/11/optimal-protein-requirements-for-older.html