I decided to take Tamerlane (aka Fuzz) and Sasabe in for a routine checkup on April 2, 2005.  Sasabe had turned eight in March and Tamerlane was going to turn eight in May, so it seemed like a good idea.  Neither cat had any history of health problems and neither was showing any symptoms.

We were a bit surprised when they weighed Fuzz and came up with a number that was a pound less than he'd weighed three months previously, but we figured he'd been moving around on the scale and had thrown off the reading.  We were more alarmed when, upon Sasabe's exam, the vet picked up a heart murmur.  The first suspect was hyperthyroidism, which commonly causes heart murmurs in cats.  We had planned to do bloodwork on both cats anyway, so we waited for the results before we decided on our next step.  

In the meantime, I weighed Fuzz at home and confirmed that he had, indeed, lost a pound.  When the results came, everyone was confused:  Sasabe's thyroid was fine, and Fuzz was hyperthyroid.  Thinking the lab was switched the results, we re-tested Sasabe.  They hadn't switched the results.  (An ultrasound determined that Sasabe has hypertrophic cardiomyopathy.)

Hyperthyroidism is fairly common in cats and is almost always caused by a benign tumor on the thyroid.  If left untreated, it can cause serious medical problems, but it can usually be managed quite well with medication or eliminated altogether with surgery or radioactive iodine treatment.  Since Fuzz's weight loss (a common symptom of the illness) was very recent, we believe we caught the problem early.

For now, he is taking Tapazole, a medication commonly used to treat hyperthyroidism, while we save up enough money to do the radioactive iodine treatment.  

June 2005 Update

Fuzz was unable to tolerate the Tapazole at all.  We managed to get his thyroid values into the normal range, but the medication made him very sick.  He'd lost about one pound before he was diagnosed, then another three pounds after we put him on the medication.  Obviously, that wasn't going to work, so in early June, he had radioactive iodine treatment (I-131).

He had to stay at the hospital for a full week, which was kind of rough, but he made many friends while he was there and came home none the worse for wear.  A scan showed the tumor was only one one side, which is good.  In early August, we'll test his thyroid again to see whether it is in the normal range.