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Guinea Pig Eye Problems: Causes and Treatment

guinea pig

Guinea pigs are adorable, and those big, soft eyes on their small faces are a major reason why. While a guinea pig’s eyelids and eyelashes help protect their vision, the fact that their eyes are large and slightly protruding predisposes them to several guinea pig eye problems. 

In addition to being susceptible to trauma and infection due to their large size, guinea pigs’ eyes are connected to their nasal passages, throats and ears. Health problems in these other body parts can often present with symptoms that may appear to be eye related while the source of the issue really lies elsewhere. That’s why veterinary consultations are so valuable. 

Another challenge for pet parents is that, as prey species, guinea pigs instinctively hide signs of injury or disease to help protect themselves from predators. When pet parents know the symptoms and causes of common guinea pig eye problems  it’s easier for them to determine when it’s time to take a trip to the veterinarian. For more information about how to properly care for your guinea pig, take a look at our guides, How to Take Care of a Guinea Pig and The Importance of Exercise for Guinea Pigs

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Corneal wounds

Since their eyes are located on the sides of their faces—and because guinea pigs often sleep with their eyes open to scan for predators—your pet is susceptible to eye damage even when they are asleep. Guinea pigs also don’t reflexively close their eyes when they sense something coming their way. Therefore, objects like chew sticks, hay, debris and even other guinea pigs can cause accidental pokes and eye problems in guinea pigs. 

One type of problem that a guinea pig can develop after being poked in the eye is a corneal wound or scratch. In addition to a direct poke, corneal wounds can be caused by irritation from food debris or an eyelash growing in the wrong direction. The fact that these pets also tend to keep their eyes open to scan for predators and can’t rub their eyes with their front legs also makes it harder for them to clear irritants from their eyes.

With some guinea pig eye problems, a cloudy coloring or a film over the eye may be noticeable. To make a definitive diagnosis, your vet will likely put a few drops of painless yellow-green dye in your pet’s eye, then flush it out with saline solution. If a corneal wound is present, the dye will adhere to the wound and highlight it. This type of wound is commonly treated with topical antibiotics and pain relievers, but severe corneal wounds that don’t heal with antibiotics may require surgery. If the cause of the wound is something as simple as debris, however, your veterinarian may just flush out your pet’s eye, give them some topical antibiotics and anti-inflammatory drops, and monitor their recovery.  

Conjunctivitis

Because guinea pigs typically blink less frequently than humans or dogs—and because they completely close their eyes even less—conjunctivitis is one of the most common guinea pig eye diseases. Conjunctivitis means inflammation of the conjunctiva (the membrane that lines the eyelids), and in guinea pigs, it is typically caused by a bacterial infection. However, there are several other potential underlying causes of conjunctivitis in guinea pigs, including viral infections, dental problems and exposure to airborne irritants like dusty bedding,  bedding made from cedar that contains irritating aromatic oils, and ammonia from a urine-soaked habitat. While there are a whole host of causes, the best way to try to prevent conjunctivitis in your guinea pig is to keep their habitat clean of waste products and to use bedding made from paper or aspen that is free of aromatic oils.

Another common cause of  guinea pig eye problems is a type of chlamydia bacteria that is specific to this rodent species. This is not the same type of chlamydia that causes venereal disease in other species. If there is conjunctivitis in your guinea pig’s eyes, white discharge is likely to be present. The discharge may also be yellow to green or crusty-looking. You may also notice that the blood vessels in the white part of your rodent’s eyes (called the sclera) are enlarged and appear red to pink. If you think your guinea pig’s eyes are bulging more than usual, see your vet right away. This is typically not a sign ofconjunctivitis and may indicate a more significant problem such as an abscess, tumor or infected tooth root behind the eye.   

Like in humans, guinea pigs with conjunctivitis are usually initially treated with antibiotic eye drops. If your vet suspects a guinea pig eye problem is due to a chlamydial infection, they may prescribe the antibiotics doxycycline or enrofloxacin, both of which are effective in eliminating chlamydia. While many guinea pigs recover fully after treatment with antibiotics, keeping your guinea pig’s habitat clean and isolating them from other guinea pigs who may have contagious conjunctivitis are key to preventing re-infection.

What is pea eye in a guinea pig?

Also commonly referred to as fatty eye by vets, pea eye is a guinea pig swollen eye problem involving the lower conjunctiva. The conjunctiva is the pale pink membrane that lines the insides of the upper and lower eyelids and covers and protects the eyeball. It is normally smooth and flat, but with pea eye, the lower conjunctiva contains a harmless pea-sized deposit of fat that causes the lower eyelid to look droopy or puffy. 

Pea eye is typically an inherited condition that is nothing more than cosmetic, as the swelling usually isn’t painful and doesn’t interfere with vision. However, if you notice your guinea pig’s eyes half-closed consistently because the bulge has grown so big, it may interfere with your pet’s vision and may require veterinary attention. Your veterinarian should be able to laser away the pea-shaped fat bulge after briefly sedating your pet.  

Issues elsewhere in the body

As previously mentioned, a guinea pig’s nasal passages, eyes and throat are all connected, so sometimes respiratory tract or ear infections can affect the eyes. Unlike other rodents, guinea pigs are unable to manufacture vitamin C (a nutrient key to a healthy immune system) in their bodies and have to ingest it to stay healthy. Vitamin C deficiency can make a guinea pig’s eyes crusty.

Other medical issues that can cause guinea pig eye problems include:

Upper respiratory infections 

If your pet is coughing and sneezing and has crusty eyes, they may have an underlying upper respiratory tract infection. 

Pneumonia 

A lower respiratory infection (an infection of the lungs that is commonly referred to as pneumonia) is a serious condition requiring immediate treatment. In addition to coughing, sneezing and difficulty breathing, signs of pneumonia can include your guinea pig’s eyes watering. If your guinea pig is showing these signs, they should be examined by a veterinarian right away.

Swollen lymph nodes 

Like other mammals, guinea pigs have lymph nodes under their bottom jaws and along their necks that function as part of their immune system to fight infection. With bacterial infections of the eyes, ears or nose, these lymph nodes often become swollen as they help fight the infection. Sometimes, bacteria directly infect the lymph nodes and form abscesses (walled off pockets of pus) that appear as large swellings under the skin along one or both sides of the neck. So, along with  guinea pig swollen eye problems, your pet may have lumpy swellings on their jaw and neck. These swellings often require surgery, along with long-term antibiotics.

Tumors 

Masses, both behind the eyes and in the brain, can put pressure on the back of the eyes and cause them to protrude. If they protrude significantly, the eyelids cannot close over them to distribute lubricating tears, and as a result, the corneas can become dry, red and irritated. In severe cases where the optic nerve from the back of the eyeball to the brain is involved, you may see your guinea pig’s eyes twitching. If your guinea pig’s eyes are protruding, you should have them checked by a vet immediately.

Take a look at our guide to some of the most Common Diseases in Guinea Pigs to learn more about these health issues and more. 

How do I tell if my guinea pig is blind?

Some guinea pigs are born blind, often due to a genetic guinea pig eye issue known as microphthalmia, in which they have smaller-than-average-size eyes or no eyes at all. As this condition is generally very obvious, it is usually diagnosed at birth. 

Other guinea pigs may go blind due to an untreated eye infection that permanently damages the eyeball, while others may go blind due to changes in their lenses associated with old age. It can be difficult to tell if your pet is blind, as they often appear to be curious and playful when you casually observe them in their usual environments. If you put a delicious treat a few inches in front of them and they don’t seem to notice it—or if your guinea pig walks around with their head tilted, like they’re using their whiskers to navigate—take them to your veterinarian. Your vet will shine a light into your pet’s eyes and look for causes of blindness. 

How do I care for a blind guinea pig?

While blindness is one of the more serious guinea pig eye problems a pet parent might face, it doesn’t mean your cavy can’t lead a happy life. If your guinea pig is blind, they may have trouble finding their guinea pig food, so you may have to hand-feed them. Try to minimize their stress levels by avoiding putting them in enclosures where loud noises may frighten them and there are unfamiliar obstacles to maneuver around. 

 Try to keep their surroundings consistent and refrain from reorganizing your pet’s living space. Blind guinea pigs should still be able to find their way around using their whiskers and hearing. Changing their surroundings might confuse them. Check out our guide, Your Guinea Pig Habitat: A Cozy Set-Up, for ideas on how to create a nice living space for your pet. When attempting to hold or stroke your guinea pig, especially if they are blind, allow them to smell and sense you beforehand so that you don’t startle them. 

Can I use eye drops for humans on guinea pigs?

No. When treating eye problems in guinea pigs, use only the drops prescribed or recommended by your veterinarian. Guinea pigs are herbivores who depend on a healthy population of normal bacteria in their gastrointestinal (GI) tracts to digest their food. As a result, they cannot take some of the antibiotics commonly prescribed for humans, as these drugs can kill many healthy GI bacteria and cause serious illness. When treating your guinea pig’s eye problems, stick to only those drugs prescribed by your veterinarian to ensure they are safe for your cavy.

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Reviewed by Petco’s Animal Care, Education and Compliance (ACE) Team

Petco’s ACE team is a passionate group of experienced pet care experts dedicated to supporting the overall health & wellness of pets. The ACE team works to develop animal care operations and standards across the organization and promote proper animal care and education for Pet Care Center partners and pet parents, while also ensuring regulatory compliance.