TL;DR: Yellow or green crust on a cat's eyes usually indicates a respiratory infection or conjunctivitis that requires veterinary attention within 24 to 48 hours to prevent permanent eye damage.
What causes yellow or green discharge and crusty eyes in my cat?
- Yellow crust is typically a sign of Feline Upper Respiratory Infection (URI) or conjunctivitis.
- These conditions are frequently caused by viruses like Feline Herpesvirus or Calicivirus, often complicated by secondary bacterial infections.
- The yellow crust is a buildup of dried pus and inflammatory cells produced by the body as it fights the infection.
Is my cat’s eye infection a veterinary emergency?
- The urgency level for crusty eyes is Medium; you should aim to have your cat seen by a veterinarian within 24 to 48 hours.
- If left untreated, severe eye infections can lead to corneal ulcers, permanent scarring, or even the loss of the eye.
- Seek immediate emergency care if the kitten is also refusing to eat, is extremely lethargic, or has labored breathing.
How does taking a photo of my cat’s eyes help with veterinary triage?
- A clear photo allows the veterinary team to see the color and consistency of the discharge before it is cleaned away.
- It helps professionals assess the degree of swelling in the eyelids and the condition of the surrounding skin.
- This visual information helps the clinic determine how quickly your pet needs to be seen.
- A photo ensures the staff is prepared for the specific type of infection your cat may be facing.
Clinical Context (Merck Veterinary Manual)
In kittens presenting with eyes glued shut and yellow crusts due to conjunctivitis, broad-spectrum antibiotics are indicated to combat secondary bacterial infections (e.g., amoxicillin with clavulanic acid, cephalosporins, trimethoprim-sulfa, fluoroquinolones, tetracyclines, chloramphenicol) as well as Chlamydia felis and Mycoplasma felis. Effective topical ophthalmic antibiotics include triple antibiotic, gentamicin, or a combination of oxytetracycline/polymyxin B ointment. Bland ophthalmic antibiotic ointments, especially those containing tetracyclines in cases of suspected C. felis, should be applied frequently (5-6 times daily) to prevent corneal irritation from dried secretions. Nasal and ocular discharges should be removed frequently.
Chapter: Infectious Disease, Ophthalmology
Source: The Merck Veterinary Manual, 11th Edition (Page 1482)