Contributors: Dennis E Brooks, David L Williams
Species: Canine | Classification: Diseases
Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading
Introduction
- Inflammation of the uveal tract (iris, ciliary body and choroid).
- Cause: infection (eg viral, bacterial, parasitic, fungal), trauma, lens damage, immune-mediated.
- Signs: severe pain, hyphemia, miosis, cloudy cornea, conjunctival hyperemia.
- Treatment: medical - many approaches.
- Prognosis: serious consequences if disease is uncontrolled.
Presenting Signs
- Ocular pain.
- Red eye (episcleral congestion).
- Lacrimation.
- Corneal edema.
- Cloudy eye.
- Iris color change.
Geographic Incidence
- Common, although true incidence is unknown.
- Fungal and rickettsia diseases vary with location.
Cost Considerations
- If surgery or specialist referral required.
- Medical treatment only is usually sufficient.
Pathogenesis
Etiology
- Often undetermined.
- Reflex uveitis Reflex uveitis.
- Systemic viral disease, eg infectious canine hepatitis Canine adenovirus type 1 disease with corneal opacity, very common.
- Systemic bacterial disease, eg leptospirosis Leptospirosis , brucellosis Brucellosis , Lyme disease Arthritis: borrelial , tuberculosis Pulmonary tuberculosis.
- Local bacterial disease, eg pasteurellosis, staphyloccocal infection (toxins).
- Septic bacterial focus, eg pyometra Pyometra.
- Parasitic, eg toxoplasmosis Toxoplasmosis , leishmaniasis Canine leishmaniosis (imported animals?).
- Mycotic infection, eg cryptococcosis , blastomycosis, histoplasmosis. Rare in temperate climate/country.
- Neoplasia - primary or secondary. Lymphoma is most common.
- Trauma, eg blunt or sharp injury or foreign bodies.
- Primary lens damage to expose lens proteins to aqueous.
- Diabetes.
- Lens-induced uveitis from cataract formation.
- Systemic hypertension.
- Auto-immune, eg uveodermatological syndrome. VKH syndrome.
- Rickettsial diseases, eg Ehlichiosis Ehrlichiosis , Rocky Mountain spotted fever.
- Immune-mediated.
- Hypermature cataracts cause lens proteins to elicit inflammation.
Pathophysiology
- Inflammation of uveal tract may involve iris (iritis), ciliary body (cyclitis), or choroid (choroiditis).
- More commonly involves all 3 (panuveitis).
- Breakdown of the blood-aqueous barrier causes anterior uveal tissue destruction.
- Increased vascular permeability is mediated by histamine, serotonin, prostaglandins and leukotrines, and causes extravasation of plasma proteins, cells and fluid.
- Iridal congestion, aqueous flare, hypopyon, keratitic precipitates and corneal edema develop along with cellular infiltration.
- Inflammation causes muscular spasm giving miosis and pain.
Timecourse
- Anterior uveitis therapy should last at least 2 months as the blood-aqueous barrier remains disrupted for about 8 weeks after insult.
Diagnosis
Presenting Problems
- Red eye.
- Ocular pain.
Client History
- Ocular pain.
- Red eye.
- Lacrimation.
- Miosis.
- Signs related to systemic disease.
- Ocular opacity.
- Iris color change.
Clinical Signs
- Episcleral congestion.
- Ocular pain - blepharospasm, photophobia.
- Miosis.
- Swollen, dull iris with loss of fine detail.
- Iris color change.
- Conjunctival hyperemia.
Diagnostic Investigation
Other
- Ophthalmoscopy:
- Illumination anterior chamber from lateral to medial - for shallow anterior chamber due to swollen iris.
- Retinal signs of systemic disease, chorioretinitis.
- Tonometry.
- Gonioscopy.
- For canine viral hepatitis, toxoplasmosis Toxoplasma antibody titer , Lyme disease, leptospirosis, mycoses.
- For neoplasia.
- To rule out systemic infectious focus, eg pyometra.
- See also Biochemistry Blood biochemistry: overview.
Gross Autopsy Findings
- The eye is inflamed with conjunctival hyperemia, episcleral congestion, corneal edema, aqueous flare and variable vision.
Histopathology Findings
- Iris and ciliary body infiltrated with a mixture of inflammatory or neoplastic cell types, depending on the cause and chronicity of the disease.
Differential Diagnosis
- Glaucoma Glaucoma.
- Reflex uveitis Reflex uveitis.
- Other causes of red eye.
- Severe retinal dysplasia Retinal dysplasia.
- Collie eye anomaly Collie eye anomaly.
- Persistent hyperplastic primary vitreous.
- Glaucoma Glaucoma.
- Diabetic retinopathy Diabetic retinopathy.
- Other causes of hyphema.
- Systemic hypertension Hypertension.
Treatment
Initial Symptomatic Treatment
- Removal of foreign body.
- Repair corneal tears.
Consider referral to specialist if foreign body present.
- Topical corticosteroids:
EitherPrednisolone acetate Prednisolone 1% - has best intraocular penetration.
OrBetamethasone sodium phosphate Betamethasone 0.1%.
OrDexamethasone Dexamethasone 0.1%. - Topical mydriatics, eg atropine sulfate Atropine 1% - to decrease ciliary spasm → decreased pain: moderate pupil dilation → decreased synechiae formation.
- Ensure that pupil is opening during the first consultation.
Treat for up to 10 days after resolution of uveitis
Use mydratics with care if secondary glaucoma
OrSystemic non-steroidal anti-inflammatory drug (NSAID), eg carprofen Carprofen.
- Systemic antibiotics and antifungals Therapeutics: antimicrobial drug.
- Systemic cytotoxic drugs, eg cyclophosphamide Cyclophosphamide , azathioprine Azathioprine if severe.
Seek specialist advice before using.
Standard Treatment
- Treat any underlying disease.
Monitoring
- Patients with severe anterior uveitis should be hospitalized for intial diagnostic workup and medical management.
Subsequent Management
Monitoring
- Tonometry for elevated IOPor to assess improvement, ie reduced IOP in uveitis.
Concurrent use of systemic corticosteroids and NSAIDs → risk of gastrointestinal side-effects.
Outcomes
Prognosis
- Variable depending on etiology.
- Early, aggresive medical therapy and a thorough diagnostic workup are required.
Expected Response to Treatment
- Decreased ocular pain.
- Easily dilated pupil.
- Reduced flare and corneal edema.
Reasons for Treatment Failure
- Complications, eg blindness, synechiae, hypopyon, hyphema, retinal detachment, secondary glaucoma, corneal edema, lens luxation, cataract formation, permanent vitreal opacities, iris bombe, optic neuritis/atrophy.
Further Reading
Publications
Refereed papers
- Recent references from PubMed and VetMedResource.
- Michau T M, Breitschwerdt E B, Gilger B C et al (2003) Bartonella vinsonii subspecies berkhoffi as a possible cause of anterior uveitis and choroiditis in a dog. Vet Ophthalmol 6 (4), 299-304 PubMed.
- Sansom J (2000) Diseases involving the anterior chamber of the dog and cat. In Practice 22 (2), 58-70 VetMedResource.
- Huss B T, Collier L L, Collins B K et al (1994) Polyarthropathy and chonoretinitis with retinal detachment in a dog with systemic histoplasmosis. JAAHA 30 (3), 217-224 VetMedResource.
- Håkanson N & Forrester S D (1990) Uveitis in the dog and cat. Vet Clin North Am Small Anim Pract 20 (3), 715-35 PubMed.
- Crispin S M (1988) Uveitis in the dog and cat. JSAP 29 (7), 429-447 PubMed.