CHRONIC PANCREATITIS / POSSIBLE EXOCRINE PANCREATIC INSUFFICIENCY

Irene started to lose weight late in 2003.  She went from about 11 pounds (4.9 kg) to about 7.5 (3.4 kg), which is quite a weight loss for a kitty.  Some of the loss was probably due to her teeth problems, which are described below, but she continued to lose after that issue was resolved, plus she had chronic diarrhea.

We tested her for just about everything and never came up with a firm diagnosis, but we suspect the culprit was exocrine pancreatic insufficiency, a condition in which the pancreas no longer produces digestive enzymes.  She was on Lipram (a pancreatic enzyme replacement) and prednisone.  After we started her on these medications, she gained weight and the diarrhea calmed down a good deal.

We believe the source of both this problem and her diabetes was chronic pancreatitis.  The cause of the pancreatitis is unknown, but I suspect it was an auto-immune problem.
EOSINOPHILIC ENTERITIS OR IRRITABLE BOWEL SYNDROME

In addition to her pancreas problems, Irene probably also had eosinophilic enteritis (aka lymphocytic-plasmacytic enteritis) or irritable bowel syndrome.  Like the pancreas problems, these conditions cause digestive difficulties and diarrhea, so it was a bit hard to tell exactly which problem was causing which symptom. 

Prednisone helped to keep the symptoms under control and we were very careful about what we fed her.  Any change in diet usually caused problems.

Like the pancreatitis, these conditions may have been auto-immune.
CALICIVIRUS, SEVERE (Probable)

In late December of 2002, several of our cats caught an upper respiratory infection from Dubh, who was fairly new to our household.  They had mild symptoms for a couple of days, then it cleared up.  Dubh had some ulcers on his tongue in addition to the upper respiratory symptoms, which told us that calicivirus was probably the culprit.

Since the symptoms were so mild, we didn't worry at first when Irene caught it; however, her battle with the virus didn't take a normal course at all.  In addition to the mild upper respiratory symptoms, she started vomiting incessantly, had bloody diarrhea, couldn't keep any food or water down, and became dehydrated.  We gave her fluids at home, but when things didn't improve, she was hospitalized on New Years Day, 2003.

While in the hospital, her breathing became labored, so now she had some very severe symptoms and on top of it, was a 12-year-old diabetic.  Everyone was fairly sure she wasn't going to survive.  She spent three days in the hospital on fluids and oxygen, and then, to everyone's surprise and delight, she began to improve.  It took her some time, but she made a complete recovery.

Although calicivirus is not usually life-threatening, it can sometimes cause ulcers in the respiratory and gastrointestinal tracts, which is apparently what happened in Irene's case.  When that sort of thing happens, it can be fatal.  Irene had other plans.
DIABETES
For quite a while after her mouth and acne problems were brought under control, Irene just didn't look right.  Her fur was dull and unkempt-looking and she'd lost weight, plus she seemed to be drinking more than normal, which is a common symptom of diabetes.  I took her in for bloodwork, and sure enough, she was diabetic.  We started her on insulin right away, then did a glucose curve some time later to make sure she was getting the right amount of insulin.
The insulin did the trick: she quickly returned to her healthy, normal self.  She received two units in the morning and one in the evening, which was a fairly low dose, but it worked well for her.  She was lucky in that respect, as many diabetic cats are a lot more difficult to treat.

For some time, I suspected she became diabetic as a result of treatment with steroids.  That is a possibility, but her chronic pancreatitis could easily have been the cause, also.

August 2003 Update:  Jessamyn was diagnosed with diabetes in August and the vet recommended that she go on pork insulin, since cats metabolize it better than human insulin.  We decided to switch Irene to pork insulin too, so we took her in to have a glucose curve done to determine the correct dosage.  The glucose curved showed that she no longer needed to be on insulin at all!

June 2005 Update:  The diabetes is back.  At this point, her blood sugar wasn't high enough for her to go back on insulin, but it was much higher than normal.  

July 2005 Update:  Her blood sugar went higher, so she went back on insulin.  I bought a human glucose monitor and checked her sugar at home, which proved to be very helpful.  You can obtain enough blood from the vein that runs near the edge of the ear to do the test.  It helps to gently pinch the vein at the base of the ear before obtaining the sample.

Although stabilizing her blood sugar helped her to feel better, she had some rather ominous symptoms that made us suspect that there was something worse than diabetes going on.  Our top suspect was, unfortunately, cancer.
FELINE ACNE
Irene had a hyperactive immune system, which first began causing problems in late 1998.  The biggest problem was the lymphocytic-plasmacytic stomatitis described below, but she also had periodic skin outbreaks and bouts of feline acne.  

Feline acne usually consists of pimple-like bumps on the cat's chin, and these can become inflamed, swollen, sore, and even infected.  We originally tried to control Bean's feline acne with steroids, but they only helped temporarily and then it came right back.  Finally, we tried a benzoyl peroxide shampoo for dogs and cats, and it worked like a charm.  If she looked like she was starting to have a problem, I just rubbed some of the shampoo onto her chin, let it sit awhile, then rinsed it off, and the acne went away.

After we got the gingivitis and diabetes under control, the feline acne all but vanished.

LYMPHOCYTIC-PLASMACYTIC STOMATITIS
In late 1998, Irene began having terrible bouts of what looked like gingivitis.  What happened was that her body decided her teeth were an enemy and began attacking and dissolving them.  In the process, she wound up with nasty inflammation and infections in her mouth, had a hard time eating, and lost quite a bit of weight. 
The best treatment for this condition is removal of the teeth, which is ultimately what we had to do.  It sounded so awful that we attempted to treat her with steroids for a while, but that didn't work.  The day after she had her teeth pulled we were sorry we hadn't had it done sooner, as she began improving rapidly.  She kept the top two canine teeth, but all the rest were removed.  This didn't stop her from enthusiastically eating dry food and anything else she came across.

February 2004 Update:  One of Bean's two remaining teeth broke and this apparently re-activated the inflammation in her mouth.  We had to have the remainder of that tooth and her one good one removed, which left her completely toothless...  It didn't seem to faze her one bit.
POSSIBLE INTESTINAL LYMPHOMA OR PANCREATIC CANCER
In April of 2005, I had an odd experience in the middle of the night.  Bean woke me up as she was curling up in bed, which happened often.  For some reason, I looked at her and immediately thought, "Oh no...she has cancer."  I don't know why I thought that.  Perhaps I'd unconsciously picked up on some subtle changes in her behavior, but nothing seemed obviously wrong with her aside from her usual problems.
Shortly after that incident, though, she began to lose weight despite eating non-stop, and she began to look like a sick cat.  In addition, she developed chronic diarrhea.  We ran all sorts of tests, but didn't come up with anything definitive.  Knocking her out and doing a biopsy was just too much of a risk for her in her condition, so we opted to treat her symptoms and give her what time she had left.  Our top two suspects, given her history and symptoms, were intestinal lymphoma and pancreatic cancer.
On September 22, 2005, she stopped purring for the first time in her life.  We gave her a day to see if she would perk up, but she didn't, plus her breathing became a bit labored by the following evening.  We knew it was time at that point.

In spite of dealing with multiple medical problems for some years, Irene was happy and cheerful right to the end.