fatty liver disease

Dear Lawrence:

It’s alright to keep your seahorses a little on the hungry side, but a fast day is probably a better alternative than trying to master the tricky balancing act between feeding less every day to help protect your seahorses against fatty liver disease and risking malnourishment from chronic underfeeding. And there are better options than fasting your seahorses if you find that depriving your seahorses of food once a week is an unattractive solution for you, as we’ll discuss later in this message.

Yes, Cherry — overfeeding your seahorses on a lipid-rich diet of fortified frozen Mysis can indeed be harmful to their long-term health. It’s entirely possible to kill these amazing animals with kindness by feeding them too much of a good thing.

Because of their lazy lifestyle, our pampered pets are susceptible to a debilitating affliction commonly known as "fatty liver disease" or hepatic lipidosis when they are given a diet that’s excessively rich in HUFA (highly unsaturated fatty acids) and other lipids. Mature seahorses that are no longer breeding are at greatest risk from hepatic lipidosis. Young seahorses need a high-fat diet to sustain their rapid growth and development, and breeding pairs that are churning out brood after brood of fry likewise need all the energy they can get. But once they reach sexual maturity, their growth rate slows markedly, and nonbreeding adults that receive a high-fat diet will begin to store excess fat in specialized cells called adipose tissue (Tamaru, Sep. 2001). Eventually these fatty deposits will begin to infiltrate the liver cells, hence the name fatty liver disease (Tamaru, Sep. 2001). In severe cases, adipose tissue can become so thick that it can literally hides the internal organs, cloaking them within a cocoon of fat, and distending the abdomen (Tamaru, Sep. 2001). When the seahorse’s liver or hepatopancreas becomes badly infiltrated with fatty deposits, it interferes with the organ’s ability to perform its vital role in digestion, food absorption, and detoxification of the blood, which has dire consequences for the affected seahorse.

Hepatic lipidosis normally does not kill its victims quickly. Ironically, due to the impairment of digestion and food absorption it causes, fatty liver disease is typically associated with chronic wasting and emaciation. Most often, the affected seahorses literally wastes away and eventually succumbs to some opportunistic disease in their weakened state.

Unfortunately, hepatic lipidosis is far more common than most seahorse keepers suspect. Of the necropsies Dr. Martin Belli has performed on hobbyist’s seahorses, fully 38% of them had fatty livers (Belli, per. com.).

Avoiding overfeeding, fasting adults once a week and using relatively low-fat enrichment products such as Vibrance II for mature seahorses that are no longer breeding are simple ways to prevent fatty liver disease.

If, like me, you find that fasting your seahorses is stressful on the aquarist, there is another alternative that both you and your seahorses may find more palatable. Fasting day always made me feel like a heartless heel, as I described in my new book on seahorses:

"The only thing I don’t like about this extremely nutritious diet is the obligatory fast day. The problem with fasting is that my Mustangs don’t seem to realize it’s good for them — that it’s absolutely in their own best interests, essential for their long-term health. Whenever I make an appearance on fast day, they insist on parading back and forth in front of the glass in their greeting colors, begging for a handout. Before my butt hits the upholstery, both of them will be dancing at the feeding station, impatiently awaiting their gourmet shrimp dinner. When it doesn’t materialize, they forlornly abandon their post at the lunch counter, and come up to stare at me through the front glass. When I still don’t take the hint, the female paces back and forth at the front, looking her brightest and most conspicuous, as though trying to attract my attention, while the male reverts to his drab everyday attire and dejectedly resumes his futile vigil at the feeding station. If not for their well-rounded cross-sections, one would think they were dying of hunger, making it difficult to resist their puppy-dog antics. Just sitting there ignoring them makes me feel like a first-class heel. Sheesh–talk about your guilt trips…Dang! I hate fast days." (Giwojna, Jun. 2002)

Lately, however, I’ve found a way out of that dilemma. It’s a fun alternative to fast days that I feel is far easier on the hobbyist and his pampered pets alike. Nowadays, rather than fasting my seahorses, I offer them a meal with a nutritional value that’s virtually nil instead: unenriched, unfed adult brine shrimp. As you can imagine, brine shrimp in this condition have very little fat content and should be considered nutritionally barren for all intents and purposes.

So once a week, instead of depriving my seahorses, I now serve them up a generous portion of unenriched adult brine shrimp. They get the thrill of hunting and eating live food and I get the fun of watching them chase after it. Instead of going hungry, my seahorses get to fill up on empty calories, while I get to avoid a guilty conscience. It’s a win-win situation. Everybody’s happy.

It’s a neat way of "fasting with a full belly," which I feel is healthy for the seahorses in more ways than one. Not only does it help guard against hepatic lipidosis from a high-fat diet, it also provides a little extra excitement for the seahorses and helps improve their quality of life in captivity.

However, if you want to try this, it’s important to observe a couple of important precautions. Remember, there is always the chance that you can introduce disease into your aquarium along with the live brine shrimp. Live Artemia (brine shrimp) are known disease vectors for a long laundry list of fish pathogens, and should be treated with caution in that regard – especially if obtained from your local fish store (LFS). The aquarist who relies on live foods for his seahorses MUST take special precautions to eliminate this potential danger!

Fortunately, there are a couple of simple measures that can minimize such risks. If you raise your own brine shrimp, remember that decapsulating Artemia cysts, removes all known parasites and pathogens, effectively sterilizing brine shrimp eggs. Large public aquaria routinely go a step further, disinfecting live foods by administering a 10-minute freshwater bath and then rinsing it thoroughly through a 100-micron strainer before offering it to their seahorses. Home hobbyists should do the same (a brine shrimp net will suffice for the strainer). Brine shrimp — the chief offender as a disease vector — tolerate this disinfection process extremely well. Many of the preferred live foods, such as Red Feeder Shrimp from Hawaii (Halocaridina rubra), Post Larval Shrimp (PLS), brine shrimp (Artemia sp.) and live Mysis are now available from High-Health facilities, which greatly minimizes the risk of disease contamination, and seahorse keepers should take full advantage of these safe vendors when purchasing live foods.

So there is an entertaining way us seahorse lovers can avoid the fast-day blues — just be sure to take sensible precautions when you do so!

Best wishes with all your fishes, Lawrence and Cherry!

Respectfully,
Pete Giwojna