TL;DR: Blood inside a cat's eye is a critical medical emergency that requires immediate veterinary evaluation to prevent permanent blindness and diagnose potentially life-threatening underlying conditions.
What does it mean when there is blood inside my cat's eye?
Blood inside the eye, medically known as hyphema, occurs when blood collects in the anterior chamber of the eye—the space between the clear cornea and the colored iris. You may see a small pool of red at the bottom of the eye, or in severe cases, the entire eye may appear dark red or cloudy. This is not a disease itself, but a sign of a significant underlying health problem or injury.
Is blood in my cat's eye considered a medical emergency?
- Hyphema is a high-priority medical emergency because it is often painful and can lead to permanent blindness or secondary glaucoma if not treated immediately.
- It is frequently a secondary symptom of life-threatening conditions such as severe high blood pressure, internal trauma, or clotting disorders.
- You should contact an emergency veterinarian right away to ensure the best possible outcome for your cat.
How can taking a photo of my cat's eye help with veterinary triage?
- A clear, well-lit photograph allows the triage team to assess the volume of blood and the condition of surrounding structures before you arrive.
- A photo provides a vital baseline to monitor whether the bleeding is worsening during your commute to the animal hospital.
- Visual documentation helps the doctor prioritize your cat's care based on the severity of the visible symptoms.
Clinical Context (Merck Veterinary Manual)
Causes of hyphema in cats include uveitis, trauma, intraocular neoplasia, retinal detachments and retinal tears, systemic hypertension, coagulation factor abnormalities, platelet disorders, hyperviscosity, and congenital ocular anomalies. Hyphema can manifest as small, focal blood clots suspended within the anterior chamber, diffuse hemorrhage occluding deeper examination, or multiple layers of hemorrhage with older clots appearing purple or black and recent hemorrhage appearing bright red. Systemic diseases common in cats, such as feline infectious peritonitis, toxoplasmosis, feline immunodeficiency virus, and feline leukemia virus, can present as anterior and posterior uveitis, retinal detachment, and secondary glaucoma, which may involve intraocular hemorrhage.
Chapter: Ophthalmology
Source: The Merck Veterinary Manual, 11th Edition (Page 497)