Feline Eye Disease
"Feline eye disease where redness (also called conjunctivitis) is present is usually caused by some type of infection. Other causes include a reduction in the production of tears, an object in the eye and allergies."
Feline herpesvirus 1 (FHV-1) - Most Common Cause of Feline Eye Disease
This virus is the most common cause of "pink eye" in cats. It transmitted from one cat to another. One or both eyes may be affected. The virus impacts the nasal cavity and the covering of the eye (conjunctiva). surface epithelium necrosis and inflammation.
Symptoms of the virus include lethargic behavior, fever, sneezing, discharge from the nose and eye discharge. In some cases ulcers form on the eye.
The virus could cause tear production to decline. This symptom is temporary in most cats.
The virus usually lasts for 2 to 3 weeks. Many veterinarian prescribe antibiotics if they believe your cat's weakened immune system will result in bacterial infection.
You might observe conjunctivitis (pink eye) and keratitis (inflammation of the covering of the eye) that lasts several weeks. If left untreated then the vision could be impaired.
Feline Herpes virus is usually diagnosed if their are no other symptoms. A lab test can determine if your cat has the disease (PCR test). If it is accompanied by an upper respiratory infection then your cat is suffering from some other type of infection such as Chlamydia or calicivirus infections.
Chlamydia Feline Eye Disease
Chlamydiosis is a bacterial infection which is the second most common cause of eye problems in cats. It is often seen in households that have more than one cat. The infection usually starts in one eye and then spreads to the other. Symptoms include conjunctivitis or redness, irritation in the nose and discharge from the eye. Discharge starts out as being watery and then as the disease progresses it turns into a thicker puss.
Unlike Feline Herpesvirus, this condition does not impact the cornea.
Diagnosis is done by a lab test. Treatment is effective and uses Tetracycline. A vaccine to prevent the condition is available.
Feline Eye Disease Associated with Vision Loss
IF Feline Herpesvirus has been ruled, out, and your veterinarian suspects vision loss then the condition affecting the eye has to be something other than conjunctivitis.
Possible disease include keratitis (inflammation of the covering over the cornea), episcleritis (nflammation of the episcleral tissue), uveitis inflammation of the uveal tract) and glaucoma (damange to the optic nerve due to high blood pressure in the eye).
Feline Keratitis (keratoconjunctivitis sicca - KCS)
This condition is known as the feline eye disease dry eye syndrome. It is diagnosed by determining the amount of tears your cat produces which in this condition means that their is less than normal tear production. If your cat is not producing enough tears it can lead to chronic conjunctivitis and keratitis. Another symptom associated with this condition is mucus discharge.
It is not know what causes this condition.
Treatment includes increasing tear production and to prevent any bacterial infections that might form. The feline herpes virus mentioned earlier could cause this condition. Once medication is started it needs to be sustained since your cat will be dependent on the medication for tears.
Keratitis can also result form a foreign object in the eye causing irritation and rubbing.
Uveitis is diagnosed when your veterinarian sees inflammation of the anterior uvea (the middle of the 3 coats that surround the eye).
Symptoms of this condition include pain, sensitivity to light (photophobia), eyes that tear too much (epiphora), deep blood vessel excessive blood flow in the eye (hyperemia), an unusually small pupil, changes in the iris(swollen) corneal edema (too much fluid), lower blood pressure in the eye, impaired vision or blindness.
Uveitis is usually seen with other conditions such as a problem with the lymph nodes, disease caused by a parasite such as a protozoa, viruses such as feline herpesvirus, fungal infections, feline infectious peritonitis (FIP), feline immunodeficiency virus (FIV), feline leukemia virus (FeLV), toxoplasmosis (from a protozoa which is a one celled organism).
Treatment includes NSAIDs to eliminate any pain your cat might be in and topical treatments and steroids to help the eye.
Your cat will be diagnosed with glaucoma is your veterinarian finds unusually high eye blood pressure. The condition could have started in the eye or could be the result of a condition somewhere else in the body (called a secondary cause).
If the feline glaucoma starts in the eye then it is due to problems with the drainage in the eye. If it was caused by another condition it is probably from uveitis (described above).
Treatment of feline glaucoma includes surgery to correct the cause of the drainage problem and the pressure issue.
Feline Eye Disease - Natural Remedies
Several herbs have a history of having a positive impact on the eye. Ingredients such as Arctium lappa (Burdock) helps to remove toxins from the body while helping the functioning of the immune system. Rosmarinus officinalis (Rosemary) helps to sooth the eyes while Chelidonium majus supports the immune system and supports good vision. An option to research is Pet Alive Eye-Heal which is made specifically for this purpose.
Ellen Bjerk's, DVM, PhD, DECVO
Norwegian School of Veterinary Science
The Red Eye Presentation
Simon M Petersen-Jones DVetMed PhD DVOphthal DipECVO MRCVS
Department of Small Animal Clinical Sciences
College of Veterinary Medicine
Michigan State University