The eye produces thick discharge in response to the bacterial infection, which builds behind the closed eyelids. If left untreated, this bacteria-filled discharge can cause permanent damage to the eye, including scarring of the cornea and opacification of the eye. In extreme cases, the cornea may rupture completely, causing blindness. Ophthalmia neonatorum can happen in one or both eyes. There is potential for the infection to spread through the body, becoming systemic. This can be life-threatening, especially for kittens as they are very fragile in their first few weeks of life.

As a kitten passes through the birth canal, it is vulnerable to any bacteria present in the mother's vagina. Parts of the eyes, especially the conjunctiva (the tissue that lines the eyelids) and the cornea (the transparent, outermost part of the eyeball), are very susceptible to bacterial infections in very young kittens. These infections often become obvious in the first 10-14 days after birth. Either the kitten will be unable to open its eyes, or it will be able open them slightly, but with excessive discharge present. A bacterial infection of the eyes in a newborn cat is often referred to as ophthalmia neonatorum, however, it may also be called neonatal ophthalmia or neonatal conjunctivitis.

Often, the first indication of an eye infection will be the eyelids of a kitten failing to open. This condition can be quite painful. It may affect multiple kittens in a litter. The eyes will appear inflamed and be quite runny. All signs to looks for include:

Most cases of ophthalmia neonatorum are caused by the mother having some sort of bacterial infection of the vagina at the time of delivery. In some instances, an unclean environment can also lead to a kitten to develop an eye infection. The infection can range from mild to severe. Known causes include:

If you suspect your kitten or kittens are showing signs of serious eye infections shortly after birth, it is best to bring both the mother and the affected kittens to a veterinary clinic to be assessed. Once there, the cats will undergo a complete physical examination by a veterinarian. The kittens will also need to have an ophthalmic examination to determine how severe the infection has become. The veterinarian will have to differentiate between ophthalmia neonatorum and other eye issues such as deformities, septicemia, and congenital glaucoma. 

Full blood work should be run on both the mother and the kittens. This would include gathering a complete blood count and a biochemical profile. Urinalysis will also be necessary, especially on the mother cat. Bacterial cultures can be performed on both the vaginal discharge of the mother and the ocular discharge of the kittens to help identify the bacteria present. Fluorescein staining may be used to better see any ulcerations that have developed on the kitten’s cornea. All of the infected cats should be tested for feline herpesvirus.

Treatment should be administered promptly to minimize damage to the eyes. In general, treatment is more effective if given early in the development of an infection. The overall goal is to open the eyelids and reduce the existing infection.

To pry the eyelids open, often a warm, wet compress will be applied to the eyes repeatedly until the eyelids can be manually separated. At this point, the eyes will need to be washed with warm saline to remove all infected discharge from the area. 

Either a broad-spectrum or a bacteria-specific antibiotic will be prescribed to remove the harmful bacteria causing the infection. These antibiotics may come in the form of drops or eye washes in addition to oral medication. Prescriptions of antibiotics generally last from one to four weeks.

Upon bringing your kitten home, you may need to continue administering a warm compress to the eyes to soothe them while the infection heals. Give your cat the appropriate antibiotics and other medications consistently as prescribed. Monitor the affected kitten or kittens for any signs of systemic infection development. If any are seen, return the kittens to the veterinary clinic for further treatment.

Clean the kitten’s eye area on a daily basis to ensure no bacteria remains. The infection may be contagious with close contact, so separating affected kittens during the healing process may be necessary. If the treatment is successful, ophthalmia neonatorum should not occur again. Scarring to the corneas and damage to the tear ducts is most often permanent. If the cat is diagnosed with feline herpesvirus, this will stay with the cat throughout its life and may flare up during times of stress.