18-Year-Old Cat Getting Fat for No Reason

“My old cat is gaining weight!”

A friendly tabby striped cat with white paws peered out through the cat carrier door.

“Doc, my wife’s mother came to visit two months ago and she said Sparky gained weight. We weren’t sure, but it did look like her belly was bigger. So we switched her to Senior weight loss food. But it looks like she’s still gaining weight.”

Actually, Sparky lost muscle over her shoulders, back, and hips while her belly sagged and grew large and pendulous. Over-all, if you picked her up, she would feel heavier. But the weight was in all the wrong places!

Why would an 18-year old cat suddenly start gaining weight?

Probably no “good” reason!

Doc Truli says,”It’s common for people to miss weight loss or gain in their pet. Then a friend or relative visits and sees the difference right away. After all, they don’t see the gradual daily change that you see, just the dramatic end results.”

A big cat belly does not mean “fat”

A dehydrated, cachectic Sparky, her huge belly full of fluid mewed at the Doc and pressed her forehead into Doc’s palm.  A big belly does not mean that your cat has gained fat.  Fat feels like, well, you know, fat.  It is firm and solid, and feels like stuffing.

An older cat that gains weight, often has gained fluid in the wrong places in the body, like the peritoneal space.  The peritoneal space is the virtual space between the abdominal organs.  Usually, there’s really only a teaspoon-full (approx 5 mL) of clear fluid in there helping everything stay lubricated and keeping your innards from rubbing against each other.  In Sparky’s case, there was over a Liter of fluid expanding the peritoneal virtual space!  A Liter (for Americans, half of a 2-Liter Coke bottle.)  No kidding, a Liter!

The peritoneal space is the virtual space between the abdominal organs and each other.  Usually, there’s really only a teaspoon-full (approx 5 mL) of clear fluid in there helping everything stay lubricated and keeping your innards from rubbing against each other.

Now, if you consider your cat might weigh 12 pounds (5 kilo) and you add that much fluid, and your cat seems “maybe a little heavier,” don’t you think that something was lost to arrive at just a little heavier.  If a weight gain is so slight you argue with yourself whether or not to go the vet’s, this weight gain is a huge deal.  It is the wrong kind of weight.  Do not self medicate your cat in this situation.  Get expert help!

Do Not Be Embarrassed, It Takes an Expert to Recognize Cat Diseases

Sparky’s dad was a physician, so he had some ideas about her weight gain.  “I’m concerned she might have diabetes, hypothyroidism, or a slow metabolism,” he said.  Fact is, hypothyroidism is incredibly rare in cats even though it is common on people, dogs, and even horses.  You would probably notice if your indoor cat urinated lakes from possible diabetes mellitus.  This kind of litter box mess rarely goes unnoticed.

If Sparky were an 80-year-old human, he might be right. Unfortunately, it’s easy to misinterpret a large belly in an older cat as fat, when the cat is actually losing valuable body condition.

Often, the fur on the cat’s back sticks up from dehydration and weight loss and the vertebrae stick put because the atrophied, tiny muscles on either side of the spine.

The symptoms of eating a lot, spine sticking out, ruffled fur, and a large belly concern a veterinarian. We think heart failure, cancer, or liver failure causing fluid build up in the abdomen.

Blood Work Gave No Answers

Guess what Sparky’s bloodwork showed?

Did you guess, nothing?

Nothing! The complete blood count and the blood chemistries showed no abnormalities! The bloodwork was totally normal.

The fluid obtained from the abdomen was clear.  Ascites is clear fluid in the abdomen.

Other causes for fluid in the abdomen include: blood, pus, urine, lymph, or rarer fluids like bile (not usually a Liter!) In a young cat, FIP, feline infectious peritonitis (wet form) will cross your veterinarian’s mind. Your veterinarian must do a belly tap procedure called abdominocentesis to get a sample and see what the fluid actually is.  Your vet cannot really tell just by looking at your cat!

Abodminocentesis sounds complex, but the procedure, done properly, is quick and almost painless.  The nurse or veterinary technician shaves the belly in an ideal area and preps the skin to remove dirt and bacteria.  Lidocaine or a similar numbing agent is often used to numb the skin, although puncturing the peritoneal lining causes the most momentary discomfort.  Some cats need sedation so they do not wiggle!  The veterinarian inserts a sterile needle into the abdomen and collects the fluid for analysis.

Abdominal Ultrasound Diagnosed the Symptom of Ascites

Abdominal ultrasound revealed the clue.

Sparky had a large growth in her abdomen extending from her liver (in us and cats just behind the diaphragm) to almost the bladder (located down by the pelvis.)

The liver has several lobes that all attach deep inside the abdomen by the diaphragm (the “solar plexus.” Sometimes, a mass or lump grows off one lobe, but not the others. In these cases, a surgeon can attempt to remove the offending mass and save the cat’s life.)

Separate Your Financial Concerns from Your Heartfelt Concerns to Reach a Clear Decision

It was a difficult decision, but Sparky did not undergo surgery. The tumor was massive and encompassed the deepest, non removable parts of the liver.

“If you’re faced with deciding whether to have your older pet undergo surgery, first set aside your financial worries to clear your mind and understand what is best for your pet separate from money concerns” says Doc Truli.

Think about your cat’s situation. (See VirtuaVet’s Quality of Life decision-making help.) In Sparky’s case, the tumor was deep, huge, and attached to a vital organ. No amount of money in the world was going to cure that problem.

We helped Sparky pass over later that afternoon. She slept peacefully and then passed away.

If you would like to see the tumor that caused Sparky’s demise, keep reading!

Cancer All Through a Cat’s Liver and her Abdomen

Warning:

The following picture shows the massive tumor. The top arrow points to a small sliver of normal-looking liver. The bottom arrow points out
the large, cavitated, fluid-producing mass. The fluid in the abdomen leaked from the mass! Poor Sparky! How uncomfortable.

The arrow points to normal appearing liver, the green circles the tumor area. The pink thing with vessels is the stomach wall, the yellow is omental fat with bumps of cancer carcinomatosis. The reddish-purple thing on the right is the spleen.

Sparky’s red and bloody spotted diaphragm and her abdominal lining (peritoneum) revealed bumps of spreading cancer.  Angry red lines from cancer streaked her thick, congested bladder wall.

Remember: if your cat gains weight for no reason, that’s a symptom!

See your trusted veterinarian today!