Contributors: Dennis E Brooks, Peter Renwick, David L Williams

 Species: Feline   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading


  • Rare.
  • Cause: inherited (juvenile or later onset), or secondary to systemic disease or ocular abnormality (eg uveitis).
  • Signs: cloudy eye, blindness.
  • Diagnosis: signs, ophthalmology.
  • Treatment: surgical removal of lens.
  • Prognosis: good following surgical removal of lens (with or without intraocular lens implantation).
    Print off the owner factsheet Cataract Cataract to give to your client.

Breed Predisposition

Cost Considerations

  • If removal of the lens is indicated.




  • Uncommon - if occurs is usually congenital.
  • Posterior polar suture line opacity (Y suture area).
  • Nuclear cataract.


  • Very rare (much more so than dog).
  • Diabetes mellitus Diabetes mellitus (but cataract not seen at the same incidence as in diabetic dogs).
  • Hyperparathyroidism Primary hyperparathyroidism.
  • Secondary nutritional cataract Cataract: nutritional - Tiger cub .


Predisposing Factors



  • Diabetes mellitus   →   increased lens glucose   →   accumulation of insoluble sugars with osmotic potential   →  water influx  →   cataract but not seen in cat as frequently as dog.
  • Uveitis   →  inflammation  →   cataract.
  • Trauma   →   free radical formation (possibly)   →   cataract.
  • Generalized progressive retinal atrophy   →   complex mechanisms (lipid peroxidation biproducts giving cataract (but not in cat as in dog))   →   cataract.

Subsequent progress

  • Cataract development varies: cortical cataracts may progress, capsular lesions are usually stable.


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


Presenting Problems

  • Cloudy eye.

Client History

  • Grayness in the eye.

Diagnostic Investigation


Differential Diagnosis

  • Nuclear sclerosis - older animals, does not compromise vision, retina visible but concentric rings in cortex due to refractive index changes.


Initial Symptomatic Treatment

  • Phacoemulsification Phacoemulsification: - early operation when eye still has vision avoids secondary problems, eg lens -induced uveitis   →   higher success rate.
  • Should only be performed by veterinary ophthalmologist.
    Surgery not appropriate for inflammatory disease. May be successful for traumatic disease if performed early, eg within days of injury.



  • Good following surgery if underlying disease controlled.

Expected Response to Treatment

Reasons for Treatment Failure

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Remillard R L, Pickett J P, Thatcher C D et al (1993) Comparison of kittens fed queen's milk with those fed milk replacers. Am J Vet Res 54 (6), 901-907 PubMed.
  • Curtis R (1990) Lens luxation in the dog and cat. Vet Clin North Am Small Anim Pract 20 (3), 755-773 PubMed.
  • Quam D D, Morris J G, Rogers Q R et al (1987) Histidine requirement of kittens for growth, haematopoiesis and prevention of cataracts. Br J Nutr 58 (3), 521-532 PubMed.
  • Whitley R D, Moore C P (1984) Advances in feline ophthalmology. Vet Clin North Am Small Anim Pract 14 (6), 1271-1288 PubMed.

Other sources of information

  • Petersen-Jones S & Crispin S (2002) BSAVA Manual of Small Animal Ophthalmology .2nd edn. British Small Animal Veterinary Association. ISBN 0 905214 54 4

Other Sources of Information