Fatty Liver in Koi – Hepatic Lipidosis Cyprinus carpio – Dietary Excess x Imbalance

QUESTION: Is this a female fish?

The “big belly” koi could be egg bound. This fish had SOME symptoms of bacterial infection.

Koi that get bigger and bigger in the belly, are often said to be “Egg Bound” but don’t be so sure. A big, fat belly certainly CAN be egg binding (which is the inability to lay their eggs) – but other pathology can explain it.

Cancers, kidney issues, liver failure, fatty liver, egg binding, and simply “obesity” can contribute to a Koi that gets “too big” and even dies.

Fatty liver comes from excessive feeding, and that can be from the owner giving too much, or perhaps the fish is just an avid, ravenous eater and out-competes everyone else for food. Either way the fish gets too many calories and puts the excess on as fat.

The gills in this fish were healthy looking. A diagnosis of bacterial septicemia would have been easier if the gills were eroded or rotting (necrotic).

Feeding poor diets without variety and with poor protein sources is a common cause of fatty liver. If a fish gets an “imbalanced” diet, which means the diet has “all the amino acid proteins but one” – the body can use NONE of the amino acids for protein synthesis. The body needs ALL the amino acids to make a protein and if one is missing, the entire pile of bricks goes to waste. Or, goes to FAT as it were.

So the liver gets a lot of fat deposited in it.

A fish can get SO fat that the liver fails. Or, the liver doesn’t have “room” to grow, be large, operate on par, and so while it’s not “failing” – it’s failing at it’s job.

The liver in this fish has been “replaced” by fat. In fact, liver tissue that even remotely resembles liver tissue is rare in this abdomen. The entire abdomen is full of ascites (hypoproteinemic – low albumin) and blood, there are hemorrhages, adhesions and other signs that bacteria helped kill this fish after the liver was largely ruined.

How to fix Hepatic Lipidosis in Koi.

That’s super hard. If you tossed a Koi with Hepatic Lipidosis into a natural pond where it would eat

Snails
Crayfish
Mud
Bugs
Plant Material
Worms
Dry Food

It would be fine. The food would be more scarce – and the variety would prevent lipidosis and probably, would correct a fatty liver. But “creating nature” and all that implies, is tough in a pond. So otherwise you cut WAY back on feeding, and then feed “preventatively” as below:

Prevention of Hepatic Lipidosis is the key.

Feed a variety of greens and grapefruit. This is not required on the daily but if you gave collards or Kale cut into long ribbons, and the fish liked it (not all Koi like it) then once a week would be better than nothing. Romaine or Arugula are okay. Iceberg lettuce is not.

Grapefruit are just cut into quarters and floated. The koi will eat the centers leaving the skin.

Buy TWO dry pellet-foods and mix them together. Mixing two different diets together tends to compensate any deficiency in one or the other diet.

Make sure that the top ingredient in any diet is “fish” or “fish meal”
If a diet has “shrimp” or “shrimp meal” that’s a plus.
“Byproduct meal” is not necessarily bad.
“Feather meal” is bad.

Buy TWO dry pellet-foods and mix them together.

If you notice the fish are getting “big bellies” on them, even when you’re mixing two high quality marine-proteins and giving greens – cut back on your feeding rate and amount. I’ve seen ponds with fish that were ‘built’ like tadpoles. Those fish have hepatic lipidosis and haven’t died yet.

In the left hand is the gonad. The gonad’s duct to the cloaca is over the right index finger. This is a male fish. None of that shenanigan was eggs, ever. This is a giant, fat male fish with hepatic lipidosis and a secondary bacterial invader.

What happens in Koi Hepatic Lipidosis?

When the liver has been replaced by fat – what you see on necropsy (post mortem) (after death) is a VERY small amount of crumbly pale liver tissue or liver tissue that’s mottled with pale areas or even yellow fat, AND a belly FULL of fluid and a LOT of pnderous amounts of, fat.

The tiny liver cannot make enough Albumin (blood protein) so the blood is thin. And the fish takes on more water than it can handle and develops ‘Dropsy’.

The hepatic lipidosis can weaken the fish, and weaken it’s immunity and then you can see the fish “suddenly” develop an infection throughout it’s body (Sepsis and peritonitis) and die fairly shortly after. You would think it died of bacterial septicemia but on closer inspection, it really “died” of simply feeding a poor diet. Or overfeeding a good diet.

How can you tell if it’s Egg Binding -VERSUS- Hepatic Lipidosis?

Well if all the fish are ponderously fat – Hepatic Lipidosis is most likely in the Koi. If it’s the “biggest female” and all your males are relatively slender – then Egg Binding seems more likely. Also, diagnostics like a knick incision, or Endoscopy, or even an Xray or an MRI could diagnosis this.

Even if the Koi “lost” the excess fat by being “on a diet” that does not “mean” that the liver will refunction.

This is why hepatic lipidosis is a “hard one”.

MIX TWO DIFFERENT FOODS TO AVOID TROUBLE AND DON’T OVERFEED

Buy ANY food on this page: Click

And then mix half-and-half with this food: