Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Blood in a cat’s eye, whether visible at the front of the eye (hyphema) or in the retina at the back, needs a vet visit the same day. In older cats, the most common cause is high blood pressure, often linked to kidney disease or hyperthyroidism, which can cause bleeding, retinal detachment, and sudden blindness. Other causes include injury, clotting problems such as rat poison, eye inflammation from infections, and cancer. Fast treatment gives the best chance of saving vision.
Signs
- Red or dark blood visible in the front of the eye
- A red or pink “cloud” in the eye
- Large, fixed, dilated pupils
- Sudden blindness: bumping into things, reluctance to jump, disorientation
- Squinting, tearing, or pawing at the eye
- A change in eye color
Causes
- High blood pressure (hypertension): the leading cause in cats over about 10, usually secondary to chronic kidney disease or hyperthyroidism.
- Trauma: falls, car accidents, or fights.
- Clotting problems: anticoagulant rat poison, low platelets, or other bleeding disorders.
- Uveitis (eye inflammation): from infections such as FIP, FeLV, FIV, or toxoplasmosis.
- Cancer, including lymphoma.
- Severe anemia or blood vessel diseases.
When to see a vet
This is urgent. See your vet the same day for any blood in the eye, sudden blindness, or dilated pupils. Go to an emergency clinic if your cat has also had an injury, has bleeding elsewhere (gums, nose, urine), may have eaten rodent bait, or is weak.
How vets diagnose it
- Blood pressure measurement
- Full eye exam, including the retina and eye pressure
- Bloodwork and urine tests for kidney disease and thyroid levels
- Clotting tests if rodent bait or a bleeding disorder is possible
- Tests for infectious diseases if uveitis is found
- Eye ultrasound if blood blocks the view
Treatment
- Blood pressure medication, most often amlodipine, started right away. Some detached retinas reattach and some vision returns when pressure is controlled quickly.
- Treating kidney disease or hyperthyroidism that caused the high blood pressure.
- Anti-inflammatory eye drops for uveitis, prescribed after the eye surface is checked.
- Vitamin K1 for anticoagulant rat poison.
- Treating infection or cancer if found.
- Glaucoma treatment if eye pressure rises.
Home care
- Keep your cat indoors and in a calm, familiar space.
- For a blind or low-vision cat: keep furniture, food, water, and litter in the same places, and block stairs and high perches at first.
- Give medications exactly as prescribed and keep blood pressure rechecks.
- Prevent rubbing with a soft cone if your vet advises.
What to avoid
- Human eye drops, including redness relievers.
- Leftover steroid eye drops, which can make some eye problems worse.
- Waiting to see if it clears. Retinal damage from high blood pressure can become permanent quickly.
Prevention
International guidelines recommend checking blood pressure regularly in cats over about 7–10 years old, and in cats with kidney disease or hyperthyroidism. Finding high blood pressure early can prevent eye damage altogether.
Frequently asked questions
Can a cat regain sight after bleeding in the eye?
Sometimes. Cats with retinal detachment from high blood pressure can regain some vision if treatment starts quickly. The longer the delay, the lower the chance.
Is blood in a cat’s eye an emergency?
Yes, treat it as urgent and see a vet the same day.
How do blind cats cope?
Very well in most cases. Cats rely on hearing, smell, and whiskers, and adapt to a stable home quickly.
Sources
- Taylor SS, et al. ISFM consensus guidelines on the diagnosis and management of hypertension in cats. J Feline Med Surg. 2017
- Acierno MJ, et al. ACVIM consensus statement: Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats. J Vet Intern Med. 2018
- Merck Veterinary Manual: Hyphema and retinal disorders in small animals
- Cornell Feline Health Center: Hypertension in cats
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.