Conjunctivitis

What is conjunctivitis?   

Conjunctivitis is an inflammation of the white lining of the inner eyelids and surface of the eyeball.  The white of the eyes becomes red and swollen, and a thick mucous discharge comes from the eye.

What causes canine (dog) and equine (horse) conjunctivitis?   

Conjunctivitis in dogs and horses is usually from allergies but also can be from dry eye, infection or surface irritants.

What causes feline (cat) conjunctivitis?

Conjunctivitis in cats is from surface infection by feline herpesvirus-1 or bacteria (Chlamydia, Mycoplasma).  Feline herpesvirus is spread directly from cat to cat by bodily fluids like nasal discharge.  Herpesvirus affects about 80% of cats and can lie latent in the nervous system or corneal surface.  During periods of cortisol or stress hormone release from the body, feline herpesvirus-1 will come out of hiding and can cause conjunctivitis, corneal ulcers and dry eye.  Chronic, recurrent or severe viral disease can lead to eyelid problems that required surgery or severe scarring to the surface of the eye that can affect vision.  

How is conjunctivitis treated?

In dogs and horses, conjunctivitis is treated by addressing the underlying allergies and anti-inflammatories.

In cats, conjunctivitis is treated with anti-viral and antibiotic medications to address the infection that causes the disease.