FARMING fish rs an ancient art.Hence treating flsh diseases .

was also an art. I say "was",because ali over the world,research units under the-controlof-veterinarians and biologistsare studying the problem aswild fish stocks run out andfarming of fish becomesessential.

In England and Wales thereare 12 Veterinary InvestigationUnits where the facil ities andexpertise are available toidentify fish diseases. NorthernIreland has one unit andScotland boasts an Institute ofAquaculture at the University ofStirling. The U.S:A. has manyresearch groups ranging fromthe U.S.A. Armed ForcesInstitute of Pathology (who runa course on the pathology offish diseases) to the annualsymposium on diseases ofornamental fish by the I

University of Georgia.The Eastern block countries

have a long tradition of thestudy of fish diseases,especially parasitology;computer reference banks arecataloguing scientific papersfroin this source at a rate ofseveral thousand annually.

The first British symposiumon pet fish diseases was held atthe Animal Studies Centre inLeicestershire in 1980, whenpxperts from many countriesgathered to discuss the subjectover two days. (Theproceedings were published,and details are given at the end -of this article).

Despite all this research, theoriginal "art" of describing andtreating fish diseases haspersisted in the popularliterature. This has given rise toimprecise (but not necessarilyinaccurate) descriptions of thediseases. This is why many so- called "Remedies" are noteffective. Some classicexamples are gjven below.SYMPTOMSA symptom (often misspeltsympton) is actually amanifestation of disease as feltand described by a patient, asopposed to a manifestation ofdisease apparent to theobserver. Hence no animal canshow symptoms - only signs.DROPSYThis condition is not a disease(although quoted as such inmost popular fish books). It is asign or manifestation of severalquite different diseases, rangingfrom bacterial infection of thegut to heart disease. Hencethere is no specific remedy totreat Dropsy.

The well-known signs ofDropsy are swelling of the bellysufficient to raise the scales of

t fish (the med-ical name isAscites). Post mortem .examination usually shows the .,body cavity to be sirn ply fu II ofwater. This is due to theosmotic effect in freshwaierfish. The fish has lost its abilityto excrete the water due toimpaired kidney function, inturn due to some other disease,parasite, or darnaqe.POPEYE -

Exopntnetrnos is the correctname of this condition. Again itis listed as a disease in many

. books with (usually chemical)treatments. Certainly the eyeitself may be infected andAlmeida et al (1968) isolated nofewer than seven different rn iero-orqanisrns from fish withPopeye. .

81MI0118 MAYfAilHead of Aquarian Laboratories, Dr. DavidFord, explains tllat so-called 'common' fishailments may not always be what they seem

A Goldfish showing the classic signs of dropsy - distended bodyand protruding scales. Dropsy is a manifestation of many differentconditions, and rarely curable.

Exopt!1almos ("Popeye") is adistressing looking condition,pifficult to pin down to aspecific cause.

Hole Head Ulcers FinlTail RotAnchor WOrm

M Fungus

White Spot

We hope none of you has a fish in this state. The diagfam shows some of the commoner diseases,andparasites that affect both tropical and coldwater species.

68 PRACTICAL FISH KEEPING

Cloudy eyes are the sign of abacterial- infection, perhapstriggered by poor water quality.

However, more often thannot, there is no sign of aspecific eye disease. Theswell ing is caused by waterfrom another condition which,in turn, "is due to some otherdistant disease.MOUTH FUNGUSThis all-too-common complaintis called "Fungus" because itresern bles the cotton - woolgrowth of Fish Funqus(Sebroieqniests}. Ordinaryfungus is a vegetable __: likeparasite that grows on the skinof the fish (and is-easily treatedby chemotherapy such asAquarian Fungus Cure). Thegreyish, mould .:_ like growthsaround the mouth are due tobacteria, not parasites, hencechemical treatment is noteffective.

The bacterium is calledFlexibacter columneris (it usedto be known as Chondrococousc,olumnaris). These are glidingbacteria that form threads(hence the fungus - likeappearance) and respond or;Jlyto antibiotic treatment.FUNGUSAs mentioned earlier, Fungus iseasily removed by dipping theaffected fish in a chemical stainsuch as Methylene Blue,Malachite Green or Acrif.lavine.The popular books 18t thesubject end wifh such treatment- which is wrong, becauseFungus is only a sign of someother, more fundamental,problem.

The spores of fungalparasites are present in allmature waters - usuallySaprolegnia thureti, sometimesAchlya prolifera. Certainly youcan remove these mo.ulds fromaffected fish, but you cannoteradicate them from theaquarium or pond waters, s.odosing the'aquarium or pond isa waste of time and money.

The ft,mgus gets a holdwhen

PRACTICAL FISH KEEPING

Many fish books'tlsr treatmentsfor fish.disease that arevirtuallyuntreatable.lchthyophoilU$ forexempte. This amoeba -likeorganism (tchtnvootnhonushoieri) is found in internal'organs as a cyst (just visiblewith a magnifying glass). Thecyst is the parasite surrounded,by dead tissue - whrCh 'protects it from attack, not onlyby the fish's defensive.rriechartisrrts, out also from anychemotherapy administered bythe aquarisLTub.erculosis is wldespread.lnthe ornamental fishes: Usuallylisted as "wastinq dlsease'',there is again no eHectivecure.·At least six species of bacteria(Van Duijn 1973)are involved _and one;Mycabacte(iummerihum that gives T8 ill, coralfishes, is also patho.genic toman. It doesn't cause h-umanIB, but does give ulcers _- -remember this when handl-ingsick flsh'saquaria: Di:sinf.ec!the .hands as well as nets and'd,tiln'tsuck siphons!

Flukes irritate fish, and theirscratching gives the-"flicking"a;~tion most retailerswill recognise. Again, most'books lisf.chemical treatmentsthat are effective in removinglhese ejdemal parasites. Whatthey do not say is that -there israrely just one species preseht.

Wh.enever'l have taken a swab, from ~ninfeSted fish and lookeddown the micrqscope I alwayssee a mixture of all kinds ofmicro-organisms. Some lay.eggs, to hatch out later whenthe treatment has apparentlycured the problem. So alWaysrepeat any standard 'anti-parasite treatment about aweek later to remove any newlyhatched .parasites, or theinfestation cycle will just start-upagain.SOME EFFECTIVETREATMENTSs6 how dO you treatdiseasedfisH scientifically, rather thanhopefully? First get to know thesubject, and recognise thesigns of specific diseases. Thebibliography list books thatdescribes these diseases.

For external parasites (bethey gill flukes, body flukes,~hite spot, fungus,. louse, etc,)

- renewed immediately._Antibiotics- should not be

~added to establ ished tanks,especially with U I G filters.They can .be used totreat ail fish- freshwater, brackish ormarine, coldW$J~r Qrt,[opical, ' .:BEFEHENCES _.,. ,

A,lmeidaet al (1968p:rQpica'i,Fish Micro,organism!rj'J. Fisb.' ,Res. of Canada, Vol. 25,;' 'No; f,1998 pp 197 to 201. Van El\lHn .(1973) (see i)ibliography). ;BIBLIOGRAPH,(~ .

Diseases,bLFishes by G.Van -Duijn Jnr. 3ro: Edition, !IilteBooks, London (1'973) 1'SB'N,.· .0-592~00072-9 (THis book iSH.owout of print but.can be f6tino irn:'.libraries. It is the,rfDosfus~ful 01>0" ,this group); <" I, . :,'

-Textbook' of Fish Dis~ases'D{'Erwin Aml~cheT, translateCl byD.A ..C:Qoroy & R.L. Herman,TFH PtJ.blications (1~70)IS BN-0~g7666~037 -5.

Parasites ~f FreshwaterFishes by Dr. G~L. Hoffman &Dr. F., P. Meyer, TFHpublications (1974).

Fi.sh Pathology byReichenback - Klinke,translated from German by.C ..Ahrens, TFH publications(1973). TFH also do a seri?s offive books'on Disease at.-Fishesby various authors - see t,heir'catalogue.. -

Waltham Sympo.sium No..,3"The Disease of Orri;'mientalFishes", can be obtai Fled fromPedigree Pettoods Animal ,Studies Cent~e, Freeb,y Lane,Waltham-on-the-Wolds, Leics.. at £3.50 post paid.

• Don't miss nextmonth's FREE booklet onfish health, compiled byDr. Ford and John Dawes,jAql.larian'sc ()wn.- experts

easltY treated with Aqua~ian Remedies 6, 8I'-!-- -

use your favourite commercialremedy such as the ten.Aquarlan Hernedies --.- thechemicals eIre ready mixed,dose levels ge§c~ibed-anddispensing r1;!ethod supplied, so.it's easy. . .

For bacterial problems(ulcers, rnqutf fungus, fin rotetc.) use anfibiotlcs. Becauseof the Medicines Act (1968)these treatments are avai tableonly onprescrtption. Therefore,get to know your localVet (seeYellow ~ages)/~ even if he isnet a fish ex.pert, he will know,who to contact for information(atthe nearest.vl Centre).

In my experience a goodgerieral purpose antibiotic isTerramycin. Pfizers' Animalgrade Terramycin contains 55grams of OxytetracycLin.ehydrochloride per kilogram, an.d.dosage is optimal at 13milligrams per litre ofaquari'Urnwater. '

One level teaspoon of thisgrade of Terramycin contains200 milligrams ofOxytetracycline hydrochloride.Therefore; since the average 24x 12 x 12" tank holds.50 litres,you need 13 x 50 which e'quals3t teaspoons. (Substitl,lte yourown size tanks into that basicequation).

Predissolve the Teramyci'l) byvigorously shaking \NitA some.water and pour into a bareaquarium, dispersing it we.lI.The water will redden. Add an'aerator to keep oxygen lel)elshigh and introduce the affectedfish. One week should proveeffective, but if the fish showsdistress, remove hirfi'. If thewater blackens, the Terramycinis breaking down <J,ndsince theby-products are poisonous, thesolution mus,tbe ed and

69