We took him to our vet Tuesday morning and got an x-ray. It turns out that his heart was enlarged and filling his chest cavity. You can't even see it on the x-rays. A couple of his siblings died of the same thing when they were little, so it wasn't a complete surprise. She said that it is really amazing with the remedies, as he wasn't exhibiting the signs that she should see in a cat with his condition. She said he has about a couple of months left at the most. He made it until today and went into congestive heart failure. Our vet wasn't in, so we had to take him in to another one in Mt. Vernon and have him go to sleep.
Wet food just isn't the same without Frodo! He was such a personable little fellow! But, he is happy now back with his Mama and Manly.