Every once in a while you get a really fun case. Here’s my definition of ‘fun,’ in case you’re wondering: 1) an even-tempered pet, 2) a willing, supportive owner, 3) a confusing series of clinical findings, 4) the diagnosis of something slightly odd but fixable and 5) getting to see the fix unfold.

Though there are plenty of fun cases that don’t meet these criteria, one kitty I’ve got in the hospital right now qualifies for all of the above.

A very old cat. A very big liver. A yellow cast to his skin. Constipation. Dehydration. Anemia. A high white blood cell count. Sky high liver enzymes. Lives indoors only. Ate well until the day before he came in. No vomiting. And, finally, a discernible, multi-textured mass in his liver visible on ultrasound.

With this series of unfortunate events, the owner was ready to put him down—I wouldn’t have blamed her. In fact, I would have supported it. It walked, talked and quacked like a cancer. But the stool check revealed another, likelier diagnosis: a liver fluke.

Cats get these nasty parasites (here in South Florida, especially) after ingesting the encysted version of this slug-like creature in the muscles of our common backyard lizards. The parasite eventually grows up to be a bile-clogging liability in the liver or, less commonly, the pancreas of these unfortunate cats.

Although there’s not a lot of literature out there on the incidence of this parasite or its pathophysiology, serious disease seems a relatively uncommon occurrence. That’s because we usually identify this parasite much earlier in a cat’s life, usually during a routine fecal examination. Outdoor cats and known lizard eaters get more regular stool checks (sometimes every three months). But in Florida, any yellow cat deserves a stool check. That’s because liver flukes like to live in the organ, gumming up the liverworks, thus causing bile pigments to back up into the cat’s blood.

Cats seem to get sick with this either when major bile ducts are clogged, when their immune system takes on the fluke (causing lots of inflammation) and/or should a severe infection result. This kitty had all three, it seems. But it had never ever even been out of doors—in his whole life. So much for our hermetically sealed South Florida homes.

Here, Palmetto bugs (large cockroaches), rats, mice and lizards make their home indoors in the most unlikely crevices. I have a family of geckoes up in the juncture between the 1920’s coral rock section of my house and the 1950’s Florida pine addition. I coexist with them peaceably, knowing they eat stray insects and cause no damage to the house itself. A bit of guano to clean up from time to time and the stray egg on my shower sill is the worst I have to fear.

And presumably, that’s how this kitty got to a lizard: one managed to make its nest indoors and the good boy made sure to eat it once it showed itself—as any self-respecting cat would.

A few shots of antibiotics, parasite killer and lots of IV fluids later and this geriatric, hyperthyroid kitty appears to be on the mend. He’s an awful lot less yellow, anyway. And he’s eating. If he’s lucky, he’ll be on his way back home today. Free to live another day in search of more indoor prey to consume.