My sister’s cat, now about 9 y.o., has developed a strange droopy belly. It hangs nearly to the floor, and sweeps from side to side as she walks.
She has never been fat. Quite the opposite. She’s also always been a bit of a runt. And she’s never been pregnant.
My father speculates that the cat is merely suffering one of the inevitable female consequences of age: sagging breasts. Does this happen?
It’s possible, though I’ve never seen anything as pronounced as what you’re describing. Remember humans are the only animals that actually have breasts, in other mammals the teats only really swell during pregnancy and dissapper after the young are weaned. If it’s developed fairly suddenly it could be a severe hernia or some form of fluid buildup. I’m not a vet but I’d sure take her in for a checkup.
My cat is male and he has exactly the same problem. He has had repeated surgeries on his front leg and I always just figured it was a result of the skin being stretched during healing (holding his leg at an odd angle) or something. Now I am intrigued!
Is she spayed?
Every (female) cat I’ve ever had has had that happen after she was spayed.
BTW, it’s not saggy tits, as their teats go all the way up to between their front legs. IIRC, they have eight total.
Also, I’m sure Cyndar will be able to answer this in her sleep.
My fixed male cat also has a saggy belly, I know he’s slightly overweight, but not obese. Most of my cats have had this little paunch, I credit good cat chow, plus I keep the my cats indoors only. They get some exercise, but not as much as an outdoor cat would get. My guess is that it is kinda like a beer belly or love handles people get when they’re older.
Yep. Many long years ago. The belly sag is a recent development.
Yep, our cat has the same “udder.” She was spayed at nine months, and developed the Dunlap’s Disease about age eight years (She’s now eleven).
The vet insists it’s normal. I guess I have to believe him, because I can’t compare her to any other cat I had, since none of them lived as long as she has.
My beloved Fluffy 
had what we called her “pouch” around her lower belly. Basically, according to one of my cat books, it enabled her to stretch and jump and run much faster.