Q.  I adopted my 2- to 3-year-old cat from a reputable shelter almost five months ago. My little girl lives strictly indoors, has had regular vet checks and has received all her vaccinations except for FIV.

Since I brought her home, she has had a problem with soft stools. It was recommended that we try a high-quality preventive formula cat food, which my cat did not care for at all. After trying a couple other recommended diets, we still did not see any improvement. Recently she began having loose stools with small amounts of blood. She's also had a couple accidents on the carpet. She never was a big eater, but she appears to be eating less as time goes by.

I recently took her to the vet, and apparently she lost another pound in the past month. Now she weighs only 8 pounds and is dehydrated. Our vet suspects the problem is more likely to be gastritis, pancreatitis or hepatitis. If the blood work comes back normal he then will test for FIV.

I have so many questions: Were all the tests appropriate? Should my cat have had a stool sample sent to the lab? Should my cat be on a prescription diet? Also, if you know anything about the prognosis of hepatitis or pancreatitis, I would appreciate your advice.

A. First, I want to commend you for adopting your friend from the shelter. The number of potential companions needing homes is overwhelming, and your little girl is certainly fortunate to be in such a loving home.

Your cat's loss of a pound in the past month is cause for considerable concern, so it is good that you are committed to getting to the root of the problem. Certainly doing blood work (with a urinalysis) is important, but I think you are also right on the mark with requesting a stool sample examination. I doubt that the routine parasitic offenders (roundworms) are suspect here, but a plethora of less frequently encountered parasites can cause these symptoms, including coccidia (unusual in this age cat, but possible), hookworms, whipworms, giardia, tritrichomonas (I think this one is particularly worth searching for), and various fungal organisms

Some of these parasites require obtaining a very fresh sample (right from the cat!) or special testing for diagnosis. Depending on the cause, treatment has varying degrees of success. Still, I think you ought to pursue a full fecal analysis to rule out these potential problems.

Your vet is on the right track looking for liver, kidney or pancreatic disease, as they can all have diarrhea as a symptom; however, pancreatic disease often does not have reliable tell-tale changes on routine blood work and requires special testing. This is quite difficult to diagnose in cats.

Performing a TLI (Trypsin-like immunoreactivity) or an ultrasound scan of the pancreas may lend more support to that diagnosis, but I hardly think that you should leap to those measures right away.

I am assuming that your kitty has been tested for the routine viral diseases, like feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV). If not, it is imperative that you do this before you invest a great deal in other testing. If she has either of these diseases, they need to be addressed. They could be the primary cause, or may merely be contributory to her current problem. If she has had an FIV vaccination, she will test positive for the FIV test. It is important to tell this to your vet.

Of course, it is impossible to tell you what is wrong, but I think that one of the most likely problems might be that she has an inflammatory or infiltrative bowel disorder. This group of diseases is often difficult to diagnose, but includes lymphocytic-plasmacytic enteritis (LPE), eosinophilic enteritis (EE), lymph sarcoma (unfortunately cancer), and feline infectious peritonitis (caused by a rather nasty virus), as potential causes of the thickening of the intestines and resultant chronic diarrhea.

Intestinal biopsies performed earlier rather than later in the course of any of these diseases will generally tell what you are dealing with, so appropriate therapy can be instituted. Full-thickness intestinal biopsies from various parts of the GI tract are preferred over endoscopic biopsies, but often we start with the less invasive endoscopic procedure first. If this does not yield an answer, we then move to a laparotomy (abdominal exploratory and biopsies). Although this may seem radical, keep in mind that it is not any more risky than a spay if performed by an experienced veterinary surgeon.

Again, you are on the right track wanting to find a diet that she can tolerate. I would think that the Wellness diet is fine, as long as she is doing well on it. However, I have had a great deal of success in such cases as this by simply placing animals on hypoallergenic veterinary diets. In addition, using medicines that control intestinal inflammation can sometimes be helpful on a trial basis if a definitive diagnosis cannot be pursued right away.

I know that getting to the bottom of such problems can seem a bit daunting; however, I know this lucky and well-loved kitty is blessed to be in your home.