Intestinal worm infection

Common Names: Intestinal worm infection
Internal parasites
Parasitic Worms
Salinity: Freshwater
Description: Parasitc worms are some of the most numerous organisms on earth, even 70% of the human population worldwide have low level infestations, and consequently the average aquaria will in all likelihood have at least a low level of infestation. Any fish regualarly ingesting livefoods will almost certainly contain internal parasites, and those fish fed with snails, shellfish, crustaceans and molluscs generally will almost certainly have comparitively high level infestations than even the piscine predators. Maany fish , in fact almost all are capable of coprophagy (thats cosuming poo to you and me!) and as such are capable of picking up worm eggs and subadults directly.

Gastrointestinal worms are a reality of life, with most individual fish mammals and amphibians living most of their lives blissfully unaware of such infections, and in some cases , actually benefitting from them. Certain nematoda (the roundworm group) often aid digestion in low numbers,by aiding the breakdown of cellulose. Other species like pinworm can also live in perfect symbiosis with the host, stimulating the stomach lining to remain thick, insulating it from bacterial harm,and keeping it enzymically active, bringing benefits to the immune system well worth the small calorific cost they charge for the service.Other worms however, are clearly parasites rather than symbians, capable of causing immediate and lasting harm, for instance, the cestodes (tapeworms) are a good example of a highly destructive parasite.. Even symbiant species may change behaviorally in response to food and population levels and can become a problem. Routine worming of fish is excessive, and may even damage the average health of a fish population.

It is when such infections occur in confined spaces , especially when intermediary hosts like shrimp and snails are present that worms become a serious health issue for the fishkeeper, with their numbers able to increase almost geometrically within a few weeks,and it is these incidences and the more harmful species that concern us here.

Overview :

Roundworm (nematodia) . These are usually small relative to the host, and have a basic typical wormlike shape, overall cylindrical with tapered ands rather like an unsectioned earthworm. The haemaglobin in the worm usually gives it a pinkish appearance. They will often go unnoticed for many years , usually causing little damage until they are stimulated into radical growth,or the numbers become too much for the fish to be able to metabolically handle the parasite burden. Roundworm occassionally eat softer available tissue, but usually confine themselves to partially digested food in the fish's gut. They may cause death by weakening and starvation, constipation, and in very rare and severe cases, death by intestinal wounds that are taken over by bacterial infections. Few species migrate to other tissues to cause problems, but its not unheard of. Fish will ocassionally vent whole roundworm, especially under treatment,and if not already under treatment , this is an ovbious sign to get on with it as expediently as possible. Roundworm are easily identified if ejected from the host. Failing that , to be sure of diagnosis provide a stool sample to the vet or university of your choice, the eggs are easily identifiable. They are on average some of the least effensive and most treatable groups of parasitic worm.

Tapeworm (Cestodes) This thoroughly unpleasant group of worms are aggressive to the gastrointestinal system immediately, and infections should be taken seriously. Initial damage is caused by the hooks on the heads with which tyhey anchor themselves into the victims soft tissues. Usually tapeworm begin by stealing predigested food from the digestive tract of the fish, and at this stage a general low weight and debilitation may be noticed.

At later stages the worms grow in size radically, and I do mean radically. Tapeworms can be longer than the total length of the host by many times. Human tapeworm can be up to 7 metres long, and even a small fish like a tiger barb can produce a tapeworm over a foot long. Tapworm will grow to fit the host and then far beyond, often eventually killing it with combination of bacterial septacaemia of the gut caused by many hundreds of hook wounds, and rapid starvation and intestinal blocking. Some may migrate to other orags to feed on fluids and soft tissue, and this includes the gills, heart, and lungs,and this is usually fatal in a very short time.

Sections of tapeworm tail, often several inches long will be ejected by the fish. Each individual section may contain hundreds to thousands of eggs, and obviously should you witness this, treatment and thorough cleaning regime needs to be initiated immediately, possibly with the breakdown of the entire tank, and decorations needing to be disposed of firmly in mind.

Tapeworm are, as the name suggests, usually long and thin, laterally flattened and heavily sectioned.Usually white to a pale yellow.

There are may other intestinal worm groups , but they are sufficiently different to mentioned in seperate profiles. These two groups will probably cover 90% of illness concerning common internal worm parasites.

Symptoms: Spots
Treatment: Roundworm : Available effective meds include. fenbendazol oxfendenazole.phenothiazine, and tramisol. Vets can suppy usually all of the aforementioned drugs, and depending on the country you live in you might even be able to find "off the shelf" solutions. Almost all however create toxins in conjuction with therenal system to purge the parasites, so it would be prudent not to overdose.

Tapeworm are hadrer to eradicate, they , rather like camallanus worms are resistant to may of the drugs that kill roundworm and often require more toxic and higher dose tretments to successfully kill them. The best control is prevention, since they are hard to treat, Source foods and cage decor carefully, and make an effort to quarantine new fish, although obviously quaranitne is only partially effective. Menbendazole, oxfenbendazole, Di-N-butyl, and various others will cause successful purges, but the eggs are not touched. Ivermectin will kill all tapeworm infestations in fish, but it is largely untested in fish apart from trout and salmon where it is used to control crustacean parasites, but in smaller aquarium fish it will consistantly cause high death rates, but for severe life threatening infections (likewise wih camallanus)it might be a worthy last ditch effort to save the fish.

Antibiotic treatments like oxytetracycline should also be considered with fish suffering the effects of hook damage to the gut wall, in order to prevent infection. If you can, keep the treatments at least a week apart from the deworming policy in order to avoid overloading the fish's renal system, but if you have to use it, then use it rather than risk the death of the fish if infection is obviously sever.
Comments: Because many intestinal worms need not be eradicated completely to retain the fish's health, and indeed preserving some gut fauna is usually beneficial you can try any number of natural pergatives, like epsom salts and crushed blanched garlic, but ultimately for severe infections, turn to proper meds. Worms often become out of control when they sense the host is weak, it forces them into taking all the nutrition they can to breed before the host dies. Consequently make sure you have investigated all possible causes of illness rather than assuming the worm infestation itself is the only cause of illness.If in any doubt though, eliminate the worms.

Tapeworm and roundworm are recognised zoonotics , and they can pass from fish to man and vice versa. Fish are often only the intemediary stage of infection, and the worms are just waiting to get into a mammalian or bird host.So make sure, if you keep fish, particularly if you ever started the syphon with your mouth, just like you would have to if you kept dogs cats livestock or anything else- worm yourself occassionally, and look after your family in that respect too.(NOT with fish meds before anyone thinks it might be a good idea!) Obviously if worried consult your doctor.
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