Equis ISSN 2398-2977

Conjunctiva: hemorrhage - subconjunctival

Contributor(s): Keith Barnett, Dennis E Brooks, Graham Munroe

Introduction

  • Common in normal neonatal foals.
  • Cause: associated in foals and adults with blunt eye trauma (dystocia in foals) and a variety of diseases causing coagulopathies and blood vessel damage, also idiopathic.
  • Signs: vary in appearance depending on duration and cause of hemorrhage.
  • Treatment: rarely specifically require treatment as spontaneously resorb.
  • Prognosis: excellent.

Pathogenesis

Etiology

  • Trauma.
  • Disease processes affecting integrity of small blood vessels.
  • Disease processes affecting hemostatic mechanism (coagulophathies).

Specific

  • In neonates - process of vaginal birth especially if difficult, or prolonged.

Pathophysiology

  • In neonatal foals - both normal and in association with neonatal maladjustment syndrome (NMS) - thought to result from increased peripheral venous pressure and compressive blunt trauma to the globe during passage through the birth canal at parturition, leading to rupture of conjunctival vessels.
  • Blunt trauma to the eye in the adult may also lead to subconjunctival hemorrhages.
  • In foals and adults other causes include:
  • Coagulopathies.
  • Any disease leading to a vasculitis, anemia or thrombocytopenia.
  • Disseminated intra-vascular coagulation (DIC)   Disseminated intravascular coagulation 
.
  • A variety of systemic infections including:
  • See individual disease entities.
  • In neonatal foals peripheral venous pressures are raised substantially and this in association with blunt compressive trauma on the globe can lead to conjunctival blood vessel rupture and varying degrees of hemorrhage depending on vascular damage and amount of spread before back pressure build-up and clotting limit it.

Diagnosis

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Treatment

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Prevention

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Munroe G A (1999) Subconjunctival haemorrhages in the neonatal Thoroughbred foal. Vet Rec 144 (11), 279-282 PubMed.


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