older cat digestion

Question
My 16 year old male cat lost a little weight this summer when it was 100+ degrees for 5 days straight.  He has not regained that weight now that winter has hit.  His appetite/activity level has not decreased at all, but I am now occasionally hearing EXTREMLEY LOUD digestion noises from him.  I cannot stress how loud his stomach noises are getting, but he exhibits NO discomfort at all %26 flatulence has not been a problem.  His coat has not changed, grooming %26 bathroom habits remain normal, eyes clear %26 bright, still active %26 talkative. He is half Siamese %26 half Russian Blue. Only medical history was a bladder infection about 13 years ago.  I feed him %26 his sister (same age) "Fancy Feast" wet food %26 a special diet (reduced ash) "Friskies" dry food.  He eats a lot of people food too (chicken/beef/bacon/hotdogs/peas).  Occasionally I also hear him making some type of throat-clearing noise after he eats.  Almost a hairball noise, but does not continue to the vomit stage.  He is a shorthair cat, %26 has never had a problem with hairballs.

Answer
Hi Pauline.  Your kitty should definitely see a vet.  Sometimes cats lose the ability to absorb nutrients from their food as they age, and they will require a prescription food that contains ingredients that are already broken down into their simplest form.  

Your vet will likely want to run some blood tests, as well.  This is because hyperthyroidism (overactive thyroid) is a very common condition which causes weight loss in older cats.  It does not always cause other symptoms.  However, it causes high blood pressure and extreme stress on the heart, so it needs to be controlled if the condition is present.  Coughing, like you mentioned, can be a signal of hyperthyroidism for two reasons.  One is that the thyroid, in the throat area, is often very enlarged and can cause discomfort swallowing.  And secondly, the heart can be affected, and if heart damage has occurred, coughing can be a symptom.

At the same time, checking his kidney levels would probably be wise.  Kidney failure is another very common condition in older cats which can cause weight loss.  A blood test, and preferably a urine test, can let you know if this is anything to worry about.

Depending on the findings during the physical exam, the vet may also suggest a blood glucose screening.  Diabetes is very common as well, especially in males over 10 years old.  Cats with diabetes tend to be very hungry, but they lose weight.  They also will drink more than usual.  Some pet owners notice weakness in their cat's hind legs when the disease becomes very advanced.  

Although this is rarely ever brought up, a surprising number of older cats have primary B-12 deficiencies, and this can cause weight loss without other symptoms.  You may need to ask your vet about a test for this specifically, if everything else comes back normal.  The treatment is typically to give a B-12 injection at home every couple of weeks.

I hope everything turns out well!

Jessica