Introduction

• Cause: bacterial disease, Aeromonas, Pseudomonas, Chlamydophila, foreign bodies, chemical agents, pesticides, vitamin A deficiency.
• Signs: blepharospasm, blepharedema, blepharitis with eyelid swelling/chemosis and mucoid discharge, caseous plaques on corneal surface or within conjunctival fornix, subspectacular abscess in snakes.
• Diagnosis: clinical signs, bacteriology.
• Treatment: topical and systemic antibiotics, cleaning/flushing of affected areas.
• Prognosis: favorable in most cases with appropriate treatment and addressing underlying husbandry issues.

Pathogenesis

Etiology

• Adnexal lesions with infectious origins more likely to be seen in captive pet reptiles are those associated with bacterial disease and can be important signs that septicemia is occurring, although they may be localized to the eye alone.
• In one study:
  • Periocular Aeromonas infections for example, were noted to cause conjunctivitis and blepharitis in a colony of lacertid lizards, while Pseudomonas was isolated from a group of anoles with conjunctivitis and blepharitis.
  • The lacertid lizards first developed a clear fluid discharge, difficult to detect initially, which eventually led to the lids sealing closed with associated visual impairment and anorexia Anorexia. Death occurred within a week of the lids sealing closed.
  • Histopathology revealed a mucopurulent ocular discharge and a prevalent growth of Aeromonas liquifaciens.
  • Treatment in the first group with oral oxytetracycline and topical ocular bathing was successful while the anoles responded well to topical gentamicin Gentamicin.
  • Vivarium hygiene was improved and ventilation increased with some effect.
  • The mealworms comprising the majority of the diet were thought to be a potential source of infection, but changing their source had no effect on the infection.
• Chlamydia is generally considered a conjunctival pathogen in birds more than in reptiles, but exudative conjunctivitis has been reported associated with Chlamydia in hatchling and juvenile crocodiles in a farm in New Guinea:
  • While this may be thought to have little relevance to pet reptiles, the problem in this situation was one introduced by the un-quarantined introduction of wild-caught animals into the farm.
  • Such a report confirms the importance of ensuring strict biosecurity when introducing new individuals into any group of captive animals.
• Other causes of conjunctivitis can include irritation from physical causes, such as small pieces of vermiculite used as a substrate, through to chemical agents, such as organochlorine pesticides reported to be associated with conjunctivitis, blepharitis and ocular discharge in eastern box turtles; such agencies are less likely to be the cause than systemic infection.
• Vitamin A deficiency:
  • Most commonly seen in tortoises and turtles.
  • Epithelial metaplasia in the form of conjunctival epithelium displaced by desquamated cells.
  • Resulting pseudoabscessation and multiple retention cyst formation can lead to accumulation of caseous material in the conjunctival sac.
  • Systemic effects of hypovitamiosis A can result in respiratory infections, renal failure, hepatic disease and egg retention.
• Can be seen in tortoises with rhinitis emerging from hibernation (post-hibernation conjunctivitis).

Predisposing factors

General

• Poor husbandry and hygiene Chelonia husbandry Lizard husbandry Snake husbandry.

Specific

• Introduction of infections from poor quarantine procedures Quarantine.

Pathophysiology

• Bacterial infections in susceptible captive reptiles dependant on health status of indivicuals and their husbandry.

Timecourse

• Several weeks for infections to resolve with appropriate therapy.

Diagnosis

Treatment

Prevention

Outcomes