Note for Pet Owners:

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Edwardsiella  is a  zoonosis associated with gastrointestinal disease and wound infections in humans. It can infect fish, amphibians, reptiles and mammals.

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Edwardsiellosis is caused by a bacterium called Edwardsiella. In humans it has been associated with gastroenteritis and wound infections. It causes septicaemia in fish, eels and flounder (fish gangrene or red disease and emphysematous putrefactive disease of catfish) 

The cause is a small, motile,  flagellated, rod-shaped facultative anaerobic, gram negative bacterium that is a member of the Enterobacteriaceae family. Species include:

E. hoshinae,  animals and humans,

E. ictaluri, nonmotile species in catfish.

E. tarda, (Edwardsiella anguillimortifera) in aquatic animals and reptiles including snakes and seals.. Occasionally found in urine, blood, and faeces of humans. In India found in children with diarrhoea.

It has a worldwide distribution and transmission to humans is via contact with infected faeces,usually from marine animals. It has been found in fish, birds, reptiles and mammals.


Infected animals may be asymptomatic but the disease is potentially fatal if left untreated. In humans it has been associated with gastroenteritis, wound infections, peritonitis and meningitis and has been reported as a cause of diarrhoea in children in India. .

 It causes septicaemia in fish, eels and flounder (fish gangrene or red disease and emphysematous putrefactive disease of catfish) 

Fish that die are usually pale with widespread haemorrhages and abscesses. Other signs may include oedema, ascites, skin erosions, gill inflammation, behavioural changes, prolapse of the rectum, eye lesions and generalised organomegaly.

Potentially fatal

Diagnosis is based on the history, clinical signs, post-mortem findings. and identification of the organism by culture on specific growth mediums such as brain–heart infusion agar, indirect fluorescent antibody testing, ELISA and loop-mediated isothermal amplification (LAMP) 


Antibiotics are the treatment of choice for infected animals and all species are susceptible to tetracyclines, aminoglycosides, most β-lactams, quinolones, antifolates, chloramphenicol, nitrofurantoin, and fosfomycin. (Stock 2001)

There are vaccinations available to prevent the disease in fish. Other preventive measures include low stocking densities,good water quality and avoidance of stress such as changes in water temperature, pH or oxygen concentrations .

If untreated infections with Edwardsiella can prove fatal 


Stock I and Wiedermann B. (2001)  Natural antibiotic susceptibilities of Edwardsiella tarda, E.ictaluri and E.hoshinae Antimicrob Agents Chemother. Aug 2001; 45(8): 2245–2255.


Updated January 2016