Introduction
- First reported in 1970.
- Cause : chronic dietary taurine deficiency.
- Signs : blindness; bilateral mydriasis and absent pupillary light reflexes.
- Diagnosis : signs, measurement of [plasma taurine].
- Treatment : supplementation of diet with taurine.
- Prognosis : depends on severity of lesions and on concurrent systemic (cardiac) disease.
Diagnosis
Clinical signs
- Reduced vision/blindness.
- Bilateral mydriasis.
- Pupillary light reflex reduced or absent in both eyes.
- Normal yellow tapetum becomes dark and granular then hyper-reflective focal lesion develops in the central area
. - In chronic cases generalized retinal atrophy occurs with loss of retinal vessels .
- Signs of dilated cardiomyopathy
(tachycardia, dyspnea, murmur).
Diagnosis
Differential diagnosis
Blindness- Retinal lesions especially those involving panretinal degeneration.
- Optic nerve lesion,
- Central nervous system lesion.
- Toxins.
- Glaucoma .
- Intraocular hemorrhage.
- Uveitis with clouded ocular media.
Sequelae
Prognosis
- Guarded, although supplementation will prevent progression of lesions and may reverse dilated cardiomyopathy, retinal damage is permanent.
Expected response to treatment
- Improvement in cardiac signs over 1-2 weeks.
- No further progression of retinal lesions.
Reasons for treatment failure
- Inadequate supplementation.
- Retinal lesions too advanced at diagnosis.
- Standard reasons for treatment failure .
Sources
Publications
Refereed papers
- Schmidt S Yet al(1976)Retinal degeneration in the taurine-deficient cat.Trans Am Acad Ophthal Otolaryngol81(4 pt 1), OP687-693.
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
