Causes, Symptoms, & Treatment Steps for Cat Conjunctivi

Causes of Feline Conjunctivitis

1. Upper respiratory infections. These infections often involve viruses, particularly feline herpesvirus and feline calicivirus, as well as bacterial and chlamydial pathogens. Symptoms of conjunctivitis typically affect both eyes, with other signs including sneezing, nasal congestion and discharge, lethargy, fever, and decreased appetite.

2. Herpesvirus. Once a cat is infected with the herpesvirus, the virus rarely clears from the body. Instead, it becomes latent and can cause recurrent conjunctivitis throughout the cat's life. These recurrent episodes may be triggered by stress, illness, certain medications, or other infections.

3. Exposure to environmental irritants or foreign substances. These irritants include cigarette smoke, household chemicals and cleaners, dust, pollen, plant materials, and sand.

4. Infections and inflammation of the eyelids and cornea. Since the conjunctiva is physically adjacent to the eyelids and cornea, any infection or inflammation in these tissues can lead to conjunctivitis. Examples include corneal ulcers, certain types of keratitis, blepharitis (eyelid inflammation), and skin diseases affecting the eyelids.

5. Allergies. Allergic conjunctivitis is not common in cats, but it is more prevalent in dogs.

6. Bacterial infections. These infections can cause conjunctivitis on top of certain preexisting eye conditions in cats. More commonly, bacteria take advantage of inflamed conjunctiva, then invade the inflamed tissue, leading to a secondary infection.

7. External trauma to the conjunctiva, eyelids, cornea, or eye.

8. Inflammation within the eye. Occasionally, inflammation can extend outward to the conjunctiva, causing conjunctivitis. In these cases, the internal eye inflammation is the primary concern to address.

Advanced Diagnosis of Feline Conjunctivitis

Diagnosis of conjunctivitis is based on the discovery of red and swollen conjunctiva during a physical examination, accompanied by symptoms such as tearing or other eye secretions. Determining the underlying cause to provide appropriate treatment can sometimes be challenging. Your veterinarian may perform the following tests:

1. A thorough eye examination to detect any foreign bodies, such as sand, plastic, or grass. It can also detect abnormal eyelid structures, abnormal eyelashes, eyelid inflammation, and corneal disorders.

2. An eye pressure test to detect glaucoma. This eye disease causes the blood vessels under the conjunctiva to enlarge, which can easily be mistaken for conjunctivitis.

3. A tear production test to determine if your cat's eyes can produce enough tears. Tear production deficiency can lead to dry eye syndrome, which can then cause conjunctivitis.

4. Fluorescein staining to determine if there are any corneal lesions. The test involves placing a drop of dye on the eye surface, then rinsing it off to examine the eye. If there are stains on the eye surface, it indicates that the cornea has been ruptured, which could be caused by abrasions, scratches, or ulcers.

In addition to these tests, your veterinarian may conduct additional tests on your cat, including:

1. Conjunctival scraping to take a sample of conjunctival cells for analysis, determining the type of inflammation.

2. Bacterial culture

3. Blood tests

Treatment of Feline Conjunctivitis

Since many cases of conjunctivitis are mild and respond to local antiinflammatory medications such as Lymdocet Sodium Neomycin Eye Drops, your veterinarian may choose to prescribe this medication before conducting additional diagnostics. If conjunctivitis does not resolve within 57 days or recurs immediately after stopping the medication, further testing may be necessary.

Once the specific cause is identified, appropriate treatment should be administered promptly.

Here are some related treatment options:

1. For cats with conjunctivitis associated with upper respiratory infections, supportive care is typically provided until the cat recovers. Tetracycline ointment or other antibiotics are often prescribed to treat the involved chlamydia and bacteria.

2. For cats with chronic recurrent conjunctivitis related to feline herpesvirus, a prescription for local antiviral drugs may be given, although they can be expensive. Some cats may also respond well to longterm oral supplementation with lysine tablets.

3. Irritants to the eyes, such as sand, plastic, or grass, can be rinsed out with large amounts of sterile eyewash solution. After removing the irritants, a short course of antibiotics or corticosteroid antibiotics may be prescribed to cure the conjunctivitis.

4. Conjunctivitis caused by environmental irritants can be difficult to treat unless the irritant is removed. Owners should avoid smoking around their cats, avoid using carpet cleaners and other agents that may linger in the environment. Furnace and air conditioner filters should be changed regularly, and air filters or humidifiers may be helpful in some cases.

5. Corneal ulcers are generally treated with local antibiotics, and sometimes with pupil dilators. Many corneal ulcers heal within three to five days.

6. For cats diagnosed with dry eye syndrome, local artificial tears and lubricants can be used to relieve conjunctivitis. Other possible medications include topical cyclosporine, which may increase tear production, as well as topical antibiotics and antiinflammatory drugs.

7. Local corticosteroids are used to treat allergic conjunctivitis. This can help reduce redness and inflammation. Removing your cat's allergens can also help eliminate the disease, although this is often not possible.

8. Inflammation of the eyelids and cornea must also be addressed promptly.