Full Version: Fatty Liver Disease
I heard mention of fatty liver disease on one of the other pages but am unsure what that is and what the symptoms are. I would like to know can anyone help?
Click to view attachmentFatty degeneration of the liver is caused by too many carbohydrates and fats in the diet, as well as a lack of choline and vitamins. The disease works in much the same way as in humans: fat builds up in and around the liver, causing it to slowly cease functioning. Healthy livers in fish should be intense dark red. In fish with fatty degeneration, the liver appears yellow-brown due to the fat droplets within it.
It is usually the result of prolonged overfeeding and/or an unvarying diet and/or feeding stale foods in which the vitamins and nutrients have broken down. Dry foods for example, have a maximum shelf-life of 2 months. After that they are nutritionally useless and should be replaced.
Unfortunately, fatty degeneration is very common in aquarium fish due to their feeding habits (the Handbook of Fish Diseases by Dieter Untergasser notes that 2 out of 3 domestic fish examined after death now display the condition to some extent).
First: regularity and quantity of food. Omnivorous fish like goldfish are designed by nature to be constant browsers and opportunists, so in the wild they pick, pick, pick all day long, only getting a tiny bit here and a tiny bit there, and having to swim constantly to find their next bit of food. This continuous 'picking' instinct is why goldfish constantly beg their owners for food even when they are full. They are not accustomed, or well-adapted, to receiving instead 2 very large meals a day plonked right in front of their noses, which is what happens in the tank environment. This results in them eating far too much, far too quickly, and overloads their systems with food. It is even worse if the owner then feeds them more food during the day! If only it was possible, it would actually be ideal to feed goldfish 20 times a day, but in absolutely miniscule amounts each time, literally half a flake or half a pellet or a tiny fingernail-pinch of vegetables or one bloodworm per fish, as this most closely replicates their natural feeding patterns. You'd never see constipation in your fish again if you fed that way!
Second: type of food. In the wild, browsing fish eat a very varied diet - algae, microscopic life, weeds, grubs, larvae, worms, perhaps some eggs and/or fry of other fish if they are lucky. They therefore get all the fats, proteins, fiber, cholines, vitamins and minerals etc. that they need. In the tank however, they might only be fed goldfish flakes or pellets for years on end. As a result, they do not receive all the nutrients that only a balanced diet brings and therefore fatty degeneration, plus other nutritional disorders, arise.
Finally, freshness of food: Wild fish always have fresh food! The algae, the grubs and worms etc. are all alive when eaten by the fish and therefore are packed chock-full of living nutriment. Dried, frozen or gelled foods simply do not hold the same nutritional value and the longer they are kept the more their vitamins and minerals disappear. You may as well feed shredded cardboard to your fish as feed 1 year old dried food. It is about as nutritious and useful (and probably about as tasty!).
So, that's what causes FLD. It's easy to prevent your fish suffering from this by feeding the correct amounts (ideally 3-4 times a day and only as much food as they can eat within 30 seconds - one minute, or twice a day and only as much as they can eat within two minutes), feeding fresh foods and feeding a varied diet each week which includes plenty of vegetables, algae and meaty foods. Including some live plants and/or leaving a bit of algae in the tank for them to nibble at is also good.
The photo below shows severe fatty degeneration of the liver and body cavity in a fish. (Sorry if it grosses anyone out!).
Hope this helps.
Edit: I forgot to mention 2 things: First, the symptoms of FLD include a slow-down in growth, lack of spawning success, swollen abdomen, disinclination to feed, sometimes darkened colour, reluctance or difficulty in swimming and increased susceptibility to other disease such as bacterial infections.
Second, LFD is NOT caused by feeding fatty foods, so don't try to cut fat out in your fish's diet! They need at least 30% fat content in their regular diet.
It is usually the result of prolonged overfeeding and/or an unvarying diet and/or feeding stale foods in which the vitamins and nutrients have broken down. Dry foods for example, have a maximum shelf-life of 2 months. After that they are nutritionally useless and should be replaced.
Unfortunately, fatty degeneration is very common in aquarium fish due to their feeding habits (the Handbook of Fish Diseases by Dieter Untergasser notes that 2 out of 3 domestic fish examined after death now display the condition to some extent).
First: regularity and quantity of food. Omnivorous fish like goldfish are designed by nature to be constant browsers and opportunists, so in the wild they pick, pick, pick all day long, only getting a tiny bit here and a tiny bit there, and having to swim constantly to find their next bit of food. This continuous 'picking' instinct is why goldfish constantly beg their owners for food even when they are full. They are not accustomed, or well-adapted, to receiving instead 2 very large meals a day plonked right in front of their noses, which is what happens in the tank environment. This results in them eating far too much, far too quickly, and overloads their systems with food. It is even worse if the owner then feeds them more food during the day! If only it was possible, it would actually be ideal to feed goldfish 20 times a day, but in absolutely miniscule amounts each time, literally half a flake or half a pellet or a tiny fingernail-pinch of vegetables or one bloodworm per fish, as this most closely replicates their natural feeding patterns. You'd never see constipation in your fish again if you fed that way!
Second: type of food. In the wild, browsing fish eat a very varied diet - algae, microscopic life, weeds, grubs, larvae, worms, perhaps some eggs and/or fry of other fish if they are lucky. They therefore get all the fats, proteins, fiber, cholines, vitamins and minerals etc. that they need. In the tank however, they might only be fed goldfish flakes or pellets for years on end. As a result, they do not receive all the nutrients that only a balanced diet brings and therefore fatty degeneration, plus other nutritional disorders, arise.
Finally, freshness of food: Wild fish always have fresh food! The algae, the grubs and worms etc. are all alive when eaten by the fish and therefore are packed chock-full of living nutriment. Dried, frozen or gelled foods simply do not hold the same nutritional value and the longer they are kept the more their vitamins and minerals disappear. You may as well feed shredded cardboard to your fish as feed 1 year old dried food. It is about as nutritious and useful (and probably about as tasty!).
So, that's what causes FLD. It's easy to prevent your fish suffering from this by feeding the correct amounts (ideally 3-4 times a day and only as much food as they can eat within 30 seconds - one minute, or twice a day and only as much as they can eat within two minutes), feeding fresh foods and feeding a varied diet each week which includes plenty of vegetables, algae and meaty foods. Including some live plants and/or leaving a bit of algae in the tank for them to nibble at is also good.
The photo below shows severe fatty degeneration of the liver and body cavity in a fish. (Sorry if it grosses anyone out!).
Hope this helps.
Edit: I forgot to mention 2 things: First, the symptoms of FLD include a slow-down in growth, lack of spawning success, swollen abdomen, disinclination to feed, sometimes darkened colour, reluctance or difficulty in swimming and increased susceptibility to other disease such as bacterial infections.
Second, LFD is NOT caused by feeding fatty foods, so don't try to cut fat out in your fish's diet! They need at least 30% fat content in their regular diet.
I want to thank you so much for that reply, and I think I need to really rearrange my guys feeding habits. I've been feeding way to much at a meal and not enough fresh foods. That makes so much sense about feeding less when it relates to their natural feeding habits. I had till now thought I was cruel if I didn't stuff them. Now I realize I was cruel for the stuffimgs. Thanks again.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.