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What are Pseudomonas?

Pseudomonas (sp.) is a gram-negative bacteria which in large quantities can cause fin-rot in fish and red leg in amphibians.

This bacteria, like many others is usually present in small quantities in the tank but regular water changes and feeding good quality food to your animals will usually keep this bacteria under control.


Edges of fins start to rot away. If left untreated fungus like Saprolegnia will attack the decaying fins and eventually the fin will disappear and the fish will die.

In amphibians, the flesh turns white and rots, revealing the deep red layers underneath. This spreads throughout the body and very often causes eventual death in the animal.


  • Poor water quality, not enough water changes.
  • Overfeeding
  • Poor quality food or stress leading to a suppressed immune system in the animal.


Usually easy to treat if caught early enough. Any gram-negative anti-bacteria treatment will get rid of it.

  • Perform a 50% water change asap.
  • A treatment of potassium permanganate will reduce the level of organic material suspended in the water and will therefore help to reduce levels of this bacteria.
  • A 1% solution of salt will help destroy this bacteria.
  • In amphibians, they breath through their skin so this bacteria can quickly kill the animal as it finds it can't get enough oxygen.

Typical products

  • Oxytetracycline
  • Erythromycin (Neomycin)
  • Interpet No9 - Anti-internal bacteria
  • Waterlife - Myxazin - broad spectrum bactericide
  • Nifurpirinol - JBL Furanol
  • Enrofloxacin
  • Oxolinic acid
  • Nitrofurazone
  • Acriflavin


  • Do not over feed your animals.
  • Regular water changes.
  • Feed a range of good quality food so your animal has a healthy immune system to fight off infection.
  • Consider adding a piece of bogwood to your tank.