Red-leg Syndrome

Also Known As: Red-leg Disease

Introduction

Red-leg syndrome is a serious condition in amphibians that is caused by septicaemia. The most common causative organism is Aeromonas hydrophila, but infection with other Aeromonas spp. and Gram-negative organisms such as Pseudomonas and Proteus spp. can also result in the disease. Infection normally occurs secondary to poor husbandry and sanitation, or the feeding of contaminated foodstuffs.

Clinical Signs

The clinical signs associated with the septicaemia are erythema and full-thickness ulceration of the skin - particularly on the limbs. Systemic signs such as anorexia and lethargy are seen prior to death. Mortality rates are high.

Diagnosis

The clinical signs are very suggestive of the condition, but specific microbiological culture is necessary to confirm diagnosis. A thioglycholate broth that is incubated at 30°C at a reduced oxygen atmosphere is used to grow the bacterium.

Treatment

Any affected or in-contact frogs should be placed in isolation, in tanks with a low stocking density. High levels of hygiene should be maintained until healing has occurred.

There are two options for medical treatment:

• Administration of an effective bacteriocidal antibiotic (based on culture and sensitivity) orally or intramuscularly to individual frogs.
• Administration of enrofloxacin to the tank water of the affected frogs.

Control

Husbandry measures such as strict quarantine, high hygiene standards and dietary control can prevent outbreaks.

Prognosis

As Gram-negative organisms are normally very virulent in amphibians, the prognosis is guarded to poor.

Red-leg Syndrome Learning Resources
Flashcards Test your knowledge using flashcard type questions	Reptiles and Amphibians Q&A 08

References

Frye, FL & Williams, DL (1995) Self-Assessment Colour Review - Reptiles & Amphibians Manson

Maclean, B (2006) Common dermatoses of ornamental fish and amphibians In Practice 2006 28: 604-613