Guinea pigs are members of the rodent family, and are popular pets in the UK. If cared for correctly guinea pigs are reasonably robust animals; however, as with any pet, they can sometimes succumb to illness. Sore eyes are a common complaint and can be the result of a number of causes. Being a prey animal guinea pigs will hide discomfort and pain, and so it can be difficult to establish how serious the problem is. 

What symptoms might be seen in a guinea pig with a sore eye?

  • Cloudy appearance to the eye
  • Discharge from the eye (it could be yellow or green in colour)
  • Watering of the eye
  • Closing of the eye
  • Crusting around the eye
  • Sore skin around the eye or eyelid

What might be the cause of my guinea pigs’ sore eye?

There are many potential causes of eye problems in guinea pigs. The following are some of the most common causes, but by no means an exhaustive list;


The most common types of conjunctivitis are infectious or allergic conjunctivitis. Infections caused by bacteria or viruses can lead to conjunctivitis in guinea pigs. The symptoms seen can include a sore red-looking eye and ocular discharge (ranging from white to yellow/green). 

Allergic conjunctivitis may be caused by irritation from something encountered in the environment such as dust (for example from hay) or cleaning products used when cleaning the cage. 

Corneal ulcers 

These occur due to damage to the surface of the eye, most commonly because of trauma (for example from a sharp piece of hay or straw). Corneal ulcers occasionally occur when the eye is too dry (dry eye, see below). Signs can include a tightly closed painful eye, a cloudy appearance to the eye or discharge.

Dry eye (keratoconjunctivitis sicca) 

“KCS” is a condition where there is a significant decrease or absent tear production. This can lead to a sore eye with a sticky appearance, and sometimes secondary issues such as corneal ulceration.

Foreign bodies 

Materials such as small pieces of hay or straw can cause a painful eye which is held shut, this can lead to corneal ulceration. 

Dental disease 

It may sound strange, but tooth problems may at times lead to eye symptoms such as a cloudy discharge or watering of the eye. This is because disease or problems with the molars or premolars can impact the tear duct, the tear duct runs close to the roots of these teeth. Other symptoms of dental disease can include reduced grooming, weight loss and increased salivation.

Respiratory disease 

Commonly caused by bacterial infection, this can also manifest with ocular symptoms such as conjunctivitis or discharge from the eyes. Other symptoms are likely to be seen such as lethargy, inappetence, sneezing and discharge from the nose.

Skin infections or disease 

Anything affecting the eyelids or skin surrounding the eyes can give the appearance of a sore eye. 

Congenital issues 

Sometimes, a guinea pig is born with abnormal development of the eye or structures around the eye, which can lead to problems. An example of a common congenital defect is entropion, where there is a rolling in of the eyelid, leading to irritation and sometimes damage to the surface of the eye from hair or eyelashes. Issues such as entropion can cause secondary complications such as corneal ulcers. Congenital problems are likely to be noticed very early on in the animal’s life. 

What should I do if I notice my guinea pig has a sore eye?

Eyes are very delicate structures, and the problems affecting them can present with incredibly similar symptoms. It can be difficult to tell a simple infection from a more serious issue such as a corneal ulcer or dry eye. If you notice that your guinea pig has a sore eye it is best to book a check-up with your vet as soon as possible.

Problems with the eye can progress quickly, and it is important that timely treatment is sought. Treatment for the sore eye will very much depend on the cause of the problem. Your veterinary surgeon will discuss the treatment plan with you according to your guinea pig’s particular problem. 

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