ISSN 2398-2977      

Conjunctivitis: bacterial

pequis

Introduction

  • Incidence: a common cause of conjunctivitis.
  • Cause: usually a secondary infection of commensals or pathogens following primary damage to conjunctiva;Moraxella equican cause a primary infection.
  • Signs: typical clinical signs of conjunctivitis   Conjunctivitis: overview  ; increased mucopurulent/purulent ocular discharge.
  • Diagnosis: bacterial culture and sensitivity testing are essential - particularly if the infection fails to respond to broad spectrum antibiotics in 5-7 days.
  • Treatment: removal of primary cause +/- treatment; topical antibiotics; fly control measures are important inMoraxellainfections.
  • Prognosis: good - most respond to treatment within 5-7 days.

Pathogenesis

Etiology

Primary infections
  • Moraxella equi.

Systemic infections

Secondary invaders

Pathophysiology

  • Bacteria are present in the conjunctival sac of most horses (commensals) - their presence alone does not indicate an infectious process   Eye: microbiology - overview  .
  • The microbial population of the conjunctival sac of horses with ocular surface disease does differ from that of the normal animal   Eye: microbiology - overview  . Gram positive bacteria are found in normal horses and gram negative bacteria in diseased horses.
  • Most bacteria act as secondary opportunists following primary damage to the conjunctiva - pathogens or commensals.
  • Specific primary infections includeMoraxella equi.
  • A few systemic bacterial infections can   →   eye infections involving the conjunctiva.
  • Most common form of bacterial conjunctivitis: primary insult   →   secondary invasion of pathogenic or opportunitic commensal bacteria   →   greater proportion of Gram negative organisms isolated than from normal eyes.
  • Moraxella equiis only pathogenic for horses - has been isolated as a cause of primary bacterial conjunctivitis particularly in USA.
  • Strangles (Streptococcus equi  Streptococcus spp  ) is recorded as causing a bilateral serous   →   purulent conjunctivitis sometimes in association with uveitis   Uveitis: anterior - overview  .
  • Other severe systemic infections may   →   loss of weight, dehydration and enophthalmos   →   conjunctival irritation and inflammation.

Diagnosis

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code