🔍 What Is Chorioretinitis?

Chorioretinitis—also known as posterior uveitis—is an inflammation of the choroid (vascular retina layer) and retina. It often arises from systemic illness and can threaten vision through retinal swelling, hemorrhage, or detachment :contentReference[oaicite:3]{index=3}.

⚠️ Why It Happens: Common Causes

• Infectious agents: Toxoplasma gondii (ocular toxo), FIP, FeLV, FIV, fungal (Histoplasma, Cryptococcus) or bacterial sepsis :contentReference[oaicite:4]{index=4}.
• Hypertension: High blood pressure leading to vascular damage and retinal hemorrhage :contentReference[oaicite:5]{index=5}.
• Immune-mediated or systemic disease: Vasculitis, neoplasia, or idiopathic posterior uveitis :contentReference[oaicite:6]{index=6}.
• Trauma or toxins: Eye injury, severe infections, or toxins like antifreeze :contentReference[oaicite:7]{index=7}.

🚩 Signs & Symptoms

• Minimal or no pain unless anterior uveitis is present :contentReference[oaicite:8]{index=8}
• Cloudy or inflamed vitreous, “floaters,” bleeding or liquefaction :contentReference[oaicite:9]{index=9}
• Fundoscopic lesions: fluffy grey-white patches, hemorrhages, retinal detachment :contentReference[oaicite:10]{index=10}
• Vision loss, dilated pupils, anisocoria, or altered reflexes :contentReference[oaicite:11]{index=11}
• Occasional ocular pain, redness, tearing, squinting if anterior segment is involved :contentReference[oaicite:12]{index=12}

🔬 Diagnostic Steps

1. History & physical: Assess systemic illness, eye changes, breed, age :contentReference[oaicite:13]{index=13}.
2. Complete eye exam: Ophthalmoscopy with pupil dilation to visualize posterior inflammation :contentReference[oaicite:14]{index=14}.
3. Fundus photography: Documents lesions, hemorrhage, and retinal detachment progression :contentReference[oaicite:15]{index=15}.
4. Blood & urine labs: Rule out FeLV, FIV, toxoplasmosis, systemic hypertension, organ dysfunction :contentReference[oaicite:16]{index=16}.
5. Imaging: Thoracic/abdominal imaging for infection, neoplasia; ocular ultrasound for detachment or masses :contentReference[oaicite:17]{index=17}.
6. Ocular fluid sampling: Aqueous or vitreous tap + PCR/cytology in select infectious cases :contentReference[oaicite:18]{index=18}.

🛠️ Treatment Approaches

A. Treat Underlying Cause

• Antiparasitics: Clindamycin for toxoplasmosis 2–4 weeks :contentReference[oaicite:19]{index=19}.
• Antivirals/antifungals: Fluconazole or itraconazole for crypto/histoplasmosis :contentReference[oaicite:20]{index=20}.
• Antibiotics: Broad-spectrum (doxycycline, azithromycin) for bacterial causes :contentReference[oaicite:21]{index=21}.
• Antihypertensives: Amlodipine to control systemic hypertension :contentReference[oaicite:22]{index=22}.
• Immunosuppressives: Prednisone or azathioprine for immune-mediated disease :contentReference[oaicite:23]{index=23}.

B. Control Inflammation

• Systemic steroids: Prednisone until underlying infection ruled out or treated :contentReference[oaicite:24]{index=24}.
• Topical anti-inflammatories: Atropine to relieve pain & prednisolone acetate for anterior uveitis involvement :contentReference[oaicite:25]{index=25}.
• Glaucoma meds: If secondary elevated intraocular pressure is present due to uveal inflammation :contentReference[oaicite:26]{index=26}.

C. Supportive & Monitoring Care

• Regular eye exam and intraocular pressure checks throughout therapy :contentReference[oaicite:27]{index=27}.
• Continue systemic treatment until resolution of lesions and systemic disease.
• Protect eyes from trauma, UV light, and ensure comfortable environment.

📅 Aftercare & Prognosis

• Vision prognosis depends on severity and retinal involvement—retinal detachment carries guarded outlook :contentReference[oaicite:28]{index=28}.
• Persistent lesions may leave scarring; routine monitoring is essential.
• Lifelong antihypertensive drugs may be necessary for hypertensive cats.
• Recheck blood pressure, general health, ocular exams every 3–6 months.
• Secondary complications (cataracts, glaucoma) require timely ophthalmic treatment.

📝 Quick Reference Table