Cat's Eyes Discharging Pus: Possible Causes & Solutions

When a cat's eyes are oozing pus and they can't open them, it typically indicates a purulent eye inflammation. This condition requires prompt cleaning of the discharge and treatment with medication based on the underlying cause. Let's delve into the common reasons and management strategies for a cat's eyes to be so affected.

Understanding the Causes and Solutions

1. Eye Conditions

Conjunctivitis: This is one of the most common eye diseases in cats, often caused by bacterial or viral infections. Symptoms include conjunctival redness, vision impairment, swelling, pain, excessive discharge, and difficulty opening the eyes.

Corneal Ulcers: Cats with corneal ulcers may also have eyes that ooze pus and cannot be opened. This is usually accompanied by cloudy corneas, photophobia, pain, and eyelid spasms.

Eyelid Inflammation (Blepharitis): This condition is characterized by hair loss around the eyes, discharge, thickened eyelid edges, and conjunctival redness. Causes can range from bacterial or parasitic infections, allergies, or trauma.

How to Address These Issues:

For Conjunctivitis and Blepharitis: Begin by rinsing the eyes with sterile saline to remove discharge. Then, use Baytril (sulfamethoxazoletrimethoprim ophthalmic solution) to control infection, applying it 3 to 5 times daily. For severe eyelid inflammation or conjunctival swelling, you can also apply erythromycin ointment or Pfizer ointment.

For Corneal Ulcers: Use levofloxacin eye drops for treatment. If there's no improvement after 2 to 3 days, seek veterinary care promptly.

2. Upper Respiratory Infections

Feline Rhinotracheitis (Herpesvirus Infection): Young cats aged 3 to 6 months are highly susceptible to this infection, which can also affect unvaccinated adult cats. Symptoms include acute conjunctivitis, corneal ulcers, purulent discharge from the nose and eyes, sneezing, lethargy, sleepiness, and loss of appetite.

Feline Calicivirus: This affects young cats aged 3 to 6 months more frequently. Symptoms include stomatitis (oral ulcers, bad breath, drooling), sneezing, increased nasal and eye discharge, loss of appetite, and limping.

Mycoplasma: Cats can easily contract mycoplasma when exposed to environments carrying the pathogen or when in contact with sick cats, especially if their immune systems are weakened. Symptoms include conjunctivitis, increased nasal and eye discharge, sneezing, coughing, and rapid breathing.

Chlamydia: This microorganism, which is between bacteria and viruses, can cause cats to sneeze, have blepharitis, conjunctival edema, increased nasal and eye discharge, and even develop treelike projections in the corners of their eyes.

How to Address These Issues:

Diagnosis: Since symptoms of these infections are similar, it's challenging to differentiate based on clinical signs. A PCR test at a veterinary hospital is necessary for diagnosis.

Treatment: For chlamydia or mycoplasma, use tetracycline ointment. Young cats may need to take Clavamox (amoxicillinclavulanate potassium) orally, while adult cats can take Doxycycline (doxycycline hyclate tablets). For feline calicivirus, use Tobramycin eye drops, chloramphenicol eye drops, and oral doxycycline to control infection, along with interferon and antiviral medications. For herpesvirus infection, use antiviral eye drops containing acyclovir or ganciclovir, alternating with antibiotic eye drops, and oral antibiotics to control infection, followed by interferon and antiviral drugs to boost immunity.

3. Eye Injuries

If a cat's eye is struck or scratched by a foreign object, the local mucous membrane can become damaged, leading to inflammation. Symptoms include swelling, tearing, and the presence of pus or bloodstreaked discharge.

How to Address Eye Injuries:

Rinse the eye with saline and apply erythromycin ointment for inflammation. Follow the vet's advice for antibiotic and analgesic medications.

4. Foreign Body Irritation

When a cat's eyes are irritated by dust, hair, sand, insects, shampoo, or刺激性smoke, they may not be able to open their eyes, tear up, and may eventually develop local inflammation and increased discharge.

How to Address Foreign Body Irritation:

Clean the eye with sterile saline to remove the foreign object and prevent infection by applying 1 to 2 drops of antibiotic eye drops.

5. Allergic Reactions

Cats can be allergic to certain substances in the environment, such as pollen, dust mites, or disinfectants. When these airborne allergens come into contact with the eyes, they can cause excessive tearing and purulent discharge, making it difficult for the cat to open their eyes.

How to Address Allergic Reactions:

Use corticosteroid eye drops like prednisolone acetate or tobramycindexamethasone eye drops under veterinary guidance. Maintain a clean environment and avoid exposing the cat to allergens.