Aeromonas infections

Common Names: Aeromonas infections
Aeromonas salmonicida
Hemorrhagic septacaemia
Red Mouth Disease
Red sore disease
Red Leg Disease (amphibian)
Aeromonas hydrophila
Aeromonas punctata
Salinity: Freshwater
Description: This is a common saprophytic infection that causes serious disease in a range of aquarium, paludarium, and terrarium subjects. It is freely transmittable between all of the major piscine, amphibian and reptilian groups and persistant infections are one of the reasons many such communities fail without proper quarantine, and prevention. This condition consumes bodily sugers and minerals and while a general gastrointestinal complaint it is most lethal when attacking the kidney in fish. At the height of its lethality it can effectively dissolve tissue and may cause pieces of flesh to die, and circulation to be completely lost in extremities. These boils or lesions that typically burst to leave exposed flesh are known as furuncles, from which this complex of diseases gets its old common name, furunculosis.

In fish, visible symptoms may include, raised veins and redness especially on fins, on the caudal peduncle, and ony other semi-opaque or transparent areas. Later infections may show bloody sores, bloating and dropsy from the kindney damage, and necrosis of both internal and external tissues.

In smaller fish , this infection commonly kills by necrosis of the gut, and there is often a characteristic swelling. The hydrogen sulphide gas may actually rupture the stomachs of small fish.

Aeromonas infections are global, although there is variability in the strains. It can be devastating to wild populations if intriduced into ecosystems where the occupants have as yet no acquired multigenerational immununity. In the early nineties, aeromonas strains thought to have been introduced by the pet trade were responsible for reducing native fish and frog numbers radically in the UK. Common frogs were hardest hit, and infections nearly halved the population.

Aeromonas are capable of destroying both fish and amphibian eggs as well as adults.
Symptoms: Spots
Treatment: This is a highly motile aeromonad, and as such water and fish must both be cleansed of infection. Average mortality rates of fish left untreated typically reach higher than 80%, so this infection must be taken seriously. Most fish have an immune system that prevent mild cases of infection, but if the parasite reaches high numbers in close confines, an entire population of fish may be wiped out.

Stressed single specimens will easily become affected and from there, the others too will become ill when constantly exposed. Treatments like furan and sulfamerazine are effective, and a really effective dosage will kill the bacteria in as little as three days, though to prevent chances of reinfection is usual to continue medication for a full week.

For recovery, fish must be given the highest quality diet, and the fatty and sugary treats usually given only occassionally can suddenly become a lifeline, helping the fish to combat the energy depletion caused by the nutrient draining abilities of this pathogen. Even mostly herbivorous species may appreciate a little frozen bloodworm, sugary fruit, or similar, to get those calories up after this infection, for at least a couple of weeks.

Notes for frog-keepers

Various dwarf frogs kept in the hobby should be treated seperately with medications and antibiotic treatment suited to their needs. It is often much harder to treat frogs with "red leg disease" than it is to cure fish, who can tolerate far more lethal medicines.The physical barries in frogs mean that medication usually needs to be administered directly rather than via water. Frogs seldom survive bad infections although the author has pulled a few through with attentive care dating in the months. Both fish and frogs should be immediately seperated for the entire duration of the illness.

This is a fast moving infection, and as such, treatment and diagnosis must be immediate for good survival rates to be maintained.When the later stages are occuring such as tissue loss and massive septacamia, its usually too late to save the fish. Thankfully the cures are fast acting on aeromonas infections in fish. Frogs have it much tougher, however and they rarely pull through. Even with the best treatment, keeping them alive is a labour of love, and many are permanently crippled by tissue loss. Many never regain the use of their limbs.
Comments: A fast growing fast spreading condition that requires a pragmatic approach to treatment. You treat it as quickly as possible, save as many specimens as you can, and move to eradicate any hint of its presence from the tank.

Surviving specimens often acquire an increased immunity quickly, and for the health of captive populations its important that survivors are bred from whenever possible as they will pass the immunity to their offspring.

A final note is to encourage safe disposal of bodies, and dispose of tankwater that may have been contaminated with bleach mixed in it for several hours before letting it go down the drain. This disease can have catastrophic consequences for species that have no legacy of constant contact with it.
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Submitted By: longhairedgit
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