Conjunctivitis in Guinea Pigs: Pink Eye, Discharge, and Treatment
- Conjunctivitis means inflammation of the tissues around the eye. In guinea pigs, it can cause redness, swelling, squinting, and clear, white, yellow, or crusty discharge.
- Common triggers include bacterial infection, hay or bedding irritation, a foreign body in the eye, and low vitamin C intake. Some guinea pigs also have eye discharge as part of a respiratory infection.
- See your vet promptly if your guinea pig is holding the eye closed, seems painful, stops eating, has cloudy eye changes, or has nasal discharge or noisy breathing along with eye symptoms.
- Treatment depends on the cause and may include eye flushing, prescribed ophthalmic antibiotics or lubricants, vitamin C support, and changes to bedding or hay quality. Human eye drops should not be used unless your vet says they are safe.
- Most uncomplicated cases improve within about 1 to 2 weeks with timely care, but deeper injury, corneal ulcers, or respiratory disease can take longer and may need more intensive treatment.
What Is Conjunctivitis in Guinea Pigs?
Conjunctivitis is inflammation of the conjunctiva, the thin pink tissue lining the eyelids and surrounding the eye. In guinea pigs, pet parents often notice it first as a red eye, sticky discharge, crusting, or a pig who keeps one eye partly closed. The problem may affect one eye or both.
This condition is not one single disease. It is a visible sign that something is irritating or infecting the eye. In guinea pigs, that can include bacterial infection, dusty hay or bedding, a piece of hay stuck under the eyelid, dry eye, or nutritional problems such as inadequate vitamin C intake.
Some cases stay mild and local to the eye. Others are part of a bigger illness, especially respiratory disease. Because guinea pigs can decline quickly when they are painful or stop eating, eye discharge and squinting deserve prompt attention from your vet.
Symptoms of Conjunctivitis in Guinea Pigs
- Red or pink tissue around the eye
- Clear, white, yellow, or crusty eye discharge
- Squinting or holding the eye closed
- Swollen eyelids or puffy conjunctiva
- Pawing at the face or rubbing the eye
- Cloudiness on the eye surface
- Reduced appetite, weight loss, or less activity
- Nasal discharge, sneezing, or noisy breathing along with eye signs
Mild redness and a little tearing can still need treatment, especially if it lasts more than a day. Guinea pigs often hide illness, so even subtle eye changes matter.
See your vet immediately if your guinea pig will not open the eye, has a cloudy or blue-looking cornea, seems very painful, stops eating, or has breathing changes with eye discharge. Those signs can point to a corneal ulcer, foreign body, or infection that is no longer limited to the eye.
What Causes Conjunctivitis in Guinea Pigs?
Several different problems can lead to conjunctivitis in guinea pigs. Infectious causes include bacteria linked to eye and respiratory disease, such as Chlamydia caviae and Bordetella bronchiseptica. In some guinea pigs, the eye problem is part of a broader upper respiratory infection rather than an isolated eye issue.
Noninfectious causes are also common. A stiff piece of hay, dusty bedding, poor ventilation, or debris trapped under the eyelid can irritate the conjunctiva and trigger redness and discharge. Corneal scratches and ulcers may start with what looks like simple pink eye, but they are more painful and need faster treatment.
Nutrition matters too. Guinea pigs must get vitamin C from their diet every day. Merck notes that guinea pigs require about 10 mg/kg/day for maintenance, and deficiency can contribute to eye problems along with other signs of scurvy. Old pellets, poor storage, and relying on vitamin C in water are common reasons intake falls short.
Less often, dry eye, dental disease affecting structures around the eye, or underlying systemic illness can contribute. That is why your vet will focus on finding the cause, not only treating the redness.
How Is Conjunctivitis in Guinea Pigs Diagnosed?
Your vet will start with a hands-on exam and a close look at the eye. They will check the eyelids, conjunctiva, cornea, and the type of discharge present. They may also ask about hay quality, bedding, ventilation, appetite, weight changes, and vitamin C intake, because those details can change the likely cause.
Common eye tests include fluorescein stain to look for a corneal ulcer or scratch and tear testing if dry eye is a concern. If your vet suspects infection, they may collect a conjunctival swab or scraping for cytology, culture, or PCR testing. Merck notes that PCR on conjunctival swabs can help confirm chlamydial conjunctivitis.
If there are sneezing, nasal discharge, weight loss, or reduced appetite, your vet may recommend a broader workup to look for respiratory disease or other illness. In some cases, diagnosis also includes checking the diet closely and correcting likely vitamin C gaps while the eye is treated.
Treatment Options for Conjunctivitis in Guinea Pigs
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Office exam with basic eye assessment
- Saline or sterile eye flush performed or recommended by your vet
- Removal of obvious surface debris if easily accessible
- Diet review with vitamin C correction plan
- Home nursing guidance: cleaner enclosure, lower-dust hay, soft paper bedding, monitoring appetite and droppings
Recommended Standard Treatment
- Exam with full ophthalmic evaluation
- Fluorescein stain and targeted eye testing as needed
- Prescription ophthalmic medication chosen by your vet, such as antibiotic drops or ointment, lubricant, or other eye medication based on findings
- Vitamin C supplementation plan if intake is inadequate
- Follow-up recheck to confirm the eye is healing
Advanced / Critical Care
- All standard care plus conjunctival cytology, culture, or PCR when infection type matters
- Assessment for concurrent respiratory disease or systemic illness
- Pain control and supportive feeding plan if appetite is reduced
- More intensive treatment for corneal ulcer, foreign body, severe swelling, or recurrent disease
- Referral to an exotics-focused vet or veterinary ophthalmologist when needed
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Conjunctivitis in Guinea Pigs
Bring these questions to your vet appointment to get the most out of your visit.
- Does this look like simple conjunctivitis, or is there a corneal ulcer or hay injury too?
- Do you think this eye problem could be part of a respiratory infection?
- Should my guinea pig have fluorescein stain, cytology, culture, or PCR testing?
- What eye medication are you prescribing, and how often should I give it?
- Is my guinea pig getting enough vitamin C, and what daily amount do you recommend?
- What bedding or hay changes would help reduce irritation while the eye heals?
- What signs mean the eye is getting worse and needs an urgent recheck?
- When should we schedule a follow-up exam to make sure the eye has healed?
How to Prevent Conjunctivitis in Guinea Pigs
Prevention starts with husbandry. Choose clean, good-quality hay with minimal dust, avoid musty or brittle hay, and use bedding that is soft and low in airborne particles. Good ventilation matters too. A damp, dirty, or poorly ventilated enclosure can irritate the eyes and increase infection risk.
Diet is another big piece. Guinea pigs need vitamin C every day because they cannot make it on their own. Fresh guinea pig pellets should be stored properly and replaced regularly, since vitamin C breaks down over time. Fresh vegetables high in vitamin C can help, but your vet can tell you whether your guinea pig also needs a supplement.
Do a quick eye check during daily handling. Look for redness, crusting, squinting, or discharge, and watch for appetite changes. Early care matters. Merck advises prompt veterinary attention for guinea pigs with eye or nasal discharge, because these pets can worsen quickly when illness or pain interferes with eating.
If one guinea pig develops eye discharge along with sneezing or other signs of illness, separate sick pets if your vet recommends it and wash your hands before and after handling. That helps reduce spread while your vet works out whether the cause is infectious, environmental, or both.