Is my Cat old or Sick

Question
I'm not sure what to do about my cat, i have a baby on the way and money is a bit tight.  That being said, i noticed my "baby" neal (12 year old tabby) is feeling boney when i pet him, and he cries oddly for his treats lately (just a cry that's a bit new, sounds like he lost his voice) also, he doesn't wrestle with the 3 year old any more, and almost keeps his distance..(up till recently he use to beat her up good, lol)  anywho.. what's going on, is my cat old or sick?
I notice he pukes alot too, but he's always been a puker.

Answer
Hi Mike.  Well first, congratulations on the bundle of joy you have on the way!

Unfortunately, there are a multitude of things that could be afflicting old Neal.  It is completely natural for cats to lose SOME muscle mass as they become geriatric (age 12 and up).  It becomes complicated, however, because there are diseases that can cause these symptoms, too.

Start with a vet exam if you can, and bring in a stool sample.  If you're lucky, the vomiting and weight loss is due to some sort of parasitic worm or protozoan infection.  Those are generally pretty easy and inexpensive to treat.  If this is negative, the vet might suggest some blood tests.  In general, a battery of blood tests will give you the most bang for your buck when you're trying to determine why a cat is losing weight.

The vet will test for diabetes, thyroid function, kidney, liver and pancreas function, as well as white blood cell and red blood cell counts.  If the cat goes outside at all, you might wish to add in tests for feline leukemia and feline AIDS.  This barrage of tests can rule in or out lots of stuff, sometimes even cancer.  The unfortunate part is they tend to be a little expensive - someplace around $150 for a decent package, at least in my neck of the woods.

Three of the most common diseases your vet will be screening for are diabetes (up to 3% of cats over 10 years old have it), kidney failure, which is a leading cause of protein loss and subsequent weight loss in cats over 12, and hyperthyroidism, which is also terribly common in cats 12 and over.

Good news is diabetes can be maintained with diet and/or insulin shots and high thyroid can be reasonably managed with a daily pill or cream rubbed into the ear.  Kidney disease is the gravest of these prognoses, but there are some things that can help.  The issue, as it always tends to be, is that these things do cost money.  For diabetes, you will require a special diet and/or insulin, needles, and blood glucose checks by the vet every couple weeks.  High thyroid is quite inexpensive to treat.  You give a medication at home twice a day and have the level checked by blood tests every couple months.  Kidney failure, if you decide to treat it, will require fluids under the skin at home, a special diet, vitamins, and several medications for stomach upset and to prevent the absorption of certain nutrients from food.

Lots to think about!  Hopefully it's something as simple as a general infection or bad teeth that are making him mopey, and treatment with antibiotics or a dental cleaning will have him back on his feet soon.