Contributors: Paul Gerding

 Species: Canine   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading


  • Important cause of visual disability.
  • Cause: inherited (juvenile or later onset), or secondary to systemic disease, eg diabetes, or ocular abnormality, eg uveitis or progressive retinal atrophy.
  • Signs: ocular opacity.
  • Treatment: surgery.
  • Prognosis: good following surgical removal of lens (with or without intra-ocular lens implantation).
    Print off the owner factsheet on Cataract to give to your client.

Presenting Signs

  • Cloudy eye.
  • Deteriorating vision.

Breed Predisposition



  • Posterior subcapsular (triangular), eg Labrador, Golden Retriever.
  • Nuclear cataract, eg Miniature Schnauzer Nuclear cataract Miniature Schnauzer 6 months old.
  • Equatorial/posterior cortex, eg Afghan Hound.
  • Posterior/anterior cortex, eg American Cocker Spaniel.
  • Posterior sutures/nuclear, eg Boston Terrier.
  • Nuclear cortex, eg Chesapeake Bay Retriever.
  • Equatorial cortex, eg Standard Poodle.
  • Nuclear/posterior cortex, eg Welsh Springer Spaniel.
  • Posterior sutures, eg West Highland White Terrier.


  • Diabetes mellitus → increased lens glucose → accumulation of insoluble sugars with osmotic potential →water influx→ cataract.
  • Uveitis →inflammation→ cataract.
  • Trauma → free radical formation (possibly) → cataract.
  • Generalized progressive retinal atrophy → complex mechanisms (not fully understood) → cataract.
  • Lens luxation.
Subsequent progress
  • Cataract development varies: cortical cataracts generally progress more quickly than capsular lesions.


  • Very variable: diabetic cataracts progress rapidly; post-trauma cataracts develop at very varying rates.


Presenting Problems

  • Cloudy eye.

Client History

  • Grayness in the eye. Care to differentiate cataract from nuclear sclerosis also giving "grayness".
  • Reduced vision.
  • Signs related to underlying etiology.

Diagnostic Investigation

  • Ophthalmoscopy: retina obscured on ophthalmoscopy Cataract primary hereditary non-congenital - American Cocker Spaniel.

Differential Diagnosis

  • Corneal opacity:
    • Edema.
    • Lipid.
    • Scar.
  • Nuclear sclerosis - older animals, does not compromise vision, retina visible but concentric rings of cortex.


Initial Symptomatic Treatment

  • Phacoemulsification: - early operation when eye still has vision avoids secondary problems, eg lens induced uveitis → higher success rate.
  • Discission/aspiration: - removal of lens cortex material by irrigation and aspiration.
  • Extracapsular lens extraction.


Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Adkins E A & Hendrix D V H (2005) Outcomes of dogs presented for cataract evaluation: a retrospective study. JAAHA 41, 235-240 PubMed.
  • Denis H M, Brooks D E, Alleman A R, Andrew S E & Plummer C (2003) Detection of anti-lens crystallin antibody in dogs with and without cataracts. Vet Ophthalmol (4), 321-327 PubMed.
  • Williams D L, Boydell I P & Long R D (1996) Current concepts in the management of canine cataract: a survey of techniques used by surgeons in Britain, Europe and the USA and a review of recent literature.​ Vet Rec 138 (15), 347-353 PubMed.

Other sources of information

  • Nasisse M P & Davidson M B (1999)Surgery of the lens.In:Veterinary Ophthalmology.3rd edn. Lippincott, Williams & Wilkins. pp 827-856.

Other Sources of Information