Equis ISSN 2398-2977

Pseudomonas spp

Contributor(s): Susan Dawson, Richard Walker




  • Family: Pseudomonaceae.
  • Genus:PseudomonasandBurkholderia.
  • 27 recognized species, the most important in horses are:B. aeruginosa,B. pseudomallei, andP. mallei.


  • Gk:pseudes- false;monas- a unit, alone.

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Clinical Effects



  • Environmental contamination; saprophytes.
  • Infected horses are the reservoir forB. mallei.


  • Endogenous or exogenous.

Pathological effects

  • Specific immune responses relatively unimportant.
  • Immunosuppression may predispose to infection.
  • Depends on species.
  • P. aeruginosa  Pseudomonas aeruginosa  is a secondary invader. Contaminates areas of the body where normal flora reduced or absent   →   liberates exotoxins   →   tissue destruction   →   keratitis   Keratitis: overview  , placentitis, septicemia, arthritis, pneumonia, endocarditis   Heart: endocarditis  and other infections.
  • P. pseudomalleiis associated with glanders   Glanders  . Invasion via intestinal wall   →   bacteremia   →   localization in respiratory tract and skin   →   miliary nodule formation.

Other Host Effects

  • Can colonize areas of the body with reduced numbers of normal flora or when tissue is injured or compromised.
  • B. pseudomalleiis associated with meliodosis.


Control via animal

  • Correct immune compromising condition.
  • Avoid contact with contaminated fomites.

Control via chemotherapies

Control via environment

  • Avoid contamination.


  • None available.


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Further Reading


Refereed papers

  • Recent references for PubMed and VetMedResource.
  • Sweeney C R & Irby N L (1996) Topical treatment of Pseudomonas spp-infected corneal ulcers in horses: 70 cases (1977-1994). JAVMA 209 (5), 954 PubMed.
  • Verma R D, Venkateswaran K S, Sharma J K & Agarwal G S (1994) Potency of partially purified malleo-proteins for mallein test in the diagnosis of glanders in equines. Vet Microbiol 41 (4), 391-397 PubMed.
  • Ensink J M, Vanklingeren B, Houwers D J et al (1993) In vitro susceptibility to antimicrobial drugs of bacterial isolates from horses in the Netherlands. Equine Vet J 25 (4), 309-313 PubMed.