Whirling disease

Common Names: Whirling disease
Myxosoma cerebralis
Black tail disease
Salinity: Freshwater
Description: This bacteria is associated primarily with the salmonid species of fish, although as time passes it seems more species fish are susceptible than originally thought.This is an easily misidentified condition, and a much overused term associated with any flagellate protozoan infection capable of causing neurological difficulty in fish, but such protozoans will be covered in the appropriate profile. This is a specific ailment, a sporazoan by nature.This is an orally transmitted parasite, usually ingested with any number of contaminated foodstuff, but a major carrier in the aquarium hobby are in fact tubifex worms. For this reason the author does not recommend the use of live tubifex , unless the source of it can be verified as safe. Freezing does not kill the spores of this species, but freeze-drying will, as even the extremely tough spores cannot survive dessication.The parasite once ingested, matures in the intestines of the fish,and will in tern each produce a further fifty sporozoites. These spores are ultimately released and will most likely infect scavenger species first in community aquaria, but may in the course of normal feeding eventually spread to all susceptible fish. First symptoms usually emerge after 12 days, the fish now suffering from lesions in the sensitive cartilage cavity surrounding the nervous system and brain cavity. At this point some cartilage in the extremeties of the fish may be affected by lesions also, thus causing some tail blackening via pigmentation damage,and this explains why it is sometimes called "black tail disease". Depending on species the lesions may range from black, through to red, white and yellow solids sometimes seen on the caudal peduncle and tailfin. Some exhibit no external symptoms apart from the characteristic "whirling" motion of swimming , which may remind some observers of a stroke victim.In some cases this is a literal truth and the infection will have caused clotting in the brain.Fish at this stage may die from the complications of exhaustion and failure to feed. Infected fish showing these symptoms cannot be saved.
Symptoms: Spots
Treatment: There is no effective treatment for infected fish ( this incidentally is a major difference from those fish suffering from protozoan infections, who can with appropriate medications, usually be saved )and only preventative measures can be taken to prevent the fish infecting its tankmates. Infected fish should be immediately quarantined , and once diagnosis verified , euthanised. Aquaria where myxasoma have become firmly established will have to be broken down and steralised. Chlorine and bleaches will successfully kill spores remaining on aquaria and equipment. In the authors opinion , once a confirmed case of whirling disease has been identified the other fish can only be protected by complete avoidance of contact with said aquarium. The only exception to this being where aquarists are already using UV sterilizers, which effectively control the spread of spores.Unfortunately there are no truly effective medications for use in the aquarium that will not be sufficiently toxic to kill the fish.
Comments: A very serious condition that must be correctly identified before commencing euthanisation protocols. Those with a protozoan infection rather than true occurance whirling disease may inadvertantly kill a collection of fish that can be saved. It is suggested that the first fish to fall victim be handed to a vet for examination, so that others may be spared the same fate. Another approach could be to treat the fish with internal antiprotozoan meds such as metronidazole for neurologically active protozoa infections. If the fish fail to respond then further steps toward euthanisation can be taken. This is one of the ailments commonly mistaken for Neon Tetra Disease in the hobby.
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Submitted By: longhairedgit
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