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Flukes, Diagnosis And Treatment Options


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Flukes, Diagnosis and Treatment Options

Flukes, part of the phylum Platyheminthes, which literally means flat worm. When many people hear the term flatworm, planaria come to mind. Planaria are a harmless, non-parasitic cousin to the fluke. Flukes are a parasite that can quickly harm and even kill your fish. They act quickly and indiscriminately, people can even get them from eating uncooked/undercooked fish. Oddly enough people are the root of the problem. Eggs of the fluke live in feces from infected humans, when those feces get into the water the fish and snails eat the eggs, the flukes hatch, people eat the fish and the whole cycle keeps going and going and going.

Fluke outbreaks in aquariums are most commonly caused by poor water conditions, stress and over crowding. They can also be brought in on new fish, another reason to quarantine all new fish before introducing them to your aquarium.

There are two main types of flukes that might be lurking on or in your fish. There are the skin/gill flukes, called Monogenea and then there are the flukes that live inside, called Trematodes.

Monogenea are fairly easy to recognize. They usually attach themselves near the gills of the fish with a sucker and two clasping hooks. Once attached the flukes constantly feed on the skin cells of the fish. This type of fluke reproduces at an alarming rate; even the young ones have even younger ones growing inside of them. It is possible for the ?mother? to have a nearly fully developed young one inside her that has yet another one growing inside it. Because of this possible three generations in one, populations of flukes can double every 24 hours. Quick intervention is critical.

The symptoms of Monogenea are easy to recognize, they begin with breathing difficulties, flashing/scratching, rapid gill movement, and yawning. As the infestation progresses the fish will become lethargic and will eventually isolate itself and spend long periods of time resting on the bottom with clamped fins. The only way to diagnose Monogenea is to do a skin scrape and gill biopsy. Monogenea can get up to 2mm in length and therefore can be easily seen with a low powered microscope, just take a skin scrape and a gill biopsy and see if you can see anything. For a good guide to taking these samples visit this site http://www.fishdoc.co.uk/microscope/micro06.htm .

Trematodes are a little harder to see because they live inside the body. They reside in the bile ducts and slowly make their way to the liver. This type of fluke is slightly less common because Trematodes require snails to reach the point in their life cycle where they can inhabit fish.

The symptoms of Trematodes are a little harder to pinpoint. They include sitting on the bottom, lethargy and rapid weight loss. The fish will appear to be just wasting away. Many times a trematode infestation will be mistaken as a bacterial infection, so it is sometimes wise to treat for flukes as well as the bacterial infection.

There are many treatment options for Monogenea, the easiest being salt dips. Consecutive treatments over 2-3 days will usually knock out any flukes living on your fish. The only trouble with the salt dips is that it only affects the flukes on your fish, not the eggs and larvae in your tank. To take care of those you need to use potassium permanganate to sterilize your tank. In order for this mode of treatment to be successful you need to keep the fish out of the infected tank until it had been sterilized and the fish has gone through 2-3 days of salt dips.

A treatment of malachite and formalin may also be effective in combating Monogenea but the higher doses are most generally needed in order to be effective. Fluke-tabs are also effective in treating for Monogenea. They contain organophosphates which are effective in killing flukes but flukes eventually build up a resistance to them. Fluke-tabs should not be used on Discus and Catfish; they are toxic to those types of fish. Great care should also be exercised when using them on Goldfish and Koi. Quite often they will experience an inflammatory dermatitis if the medicine is left in the water for over 48 hours. When using this treatment on Koi and Goldfish it is recommended that you do a 50% water change after 48 hours, wait 24 hours and then re-treat.

To treat Trematodes you need one of the many internal parasite remedies that are on the market. The most effective treatment is praziquantel, commonly known as prazi.

Flukes are easy to treat but sometimes difficult to eradicate. The earlier you catch them the easier it will be to get rid of them, early detection is the key! You should also protect yourself; never eat raw or undercooked fish, especially if it comes from Asia where an estimated 30 million people are infected. Although medical treatments are available the host may suffer permanent damage to the liver and bile ducts. If left untreated death may occur.

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  • 2 months later...
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There's some nice work there Nicole, congratulations!

One thing I would have like to see in your paper though, seeing you have aluded to the physical forms of these little nasties under the mic, is a little bit about the difference between the two types of monogenean flukes found on goldies. That being skin flukes (Gyrodactylus) and gill flukes (Dactylogyrus), as they both look different under the mic.

For those who are a little too squeamish to take a gill scrape/biopsy but have had the courage to taken a skin scrape, are in danger of not sampling dactylogyrus (which, although can be found on the body sometimes, do tend to mainly be found in the gills) and hence misdiagnose.


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