Guinea pigs, like many other exotic pets, are prone to eye problems. There are a variety of diseases and issues that can affect the health of your guinea pig’s eyes but some of these problems are seen more commonly than others. By familiarizing yourself with some of the possibilities, you’ll be better prepared to deal with any eye problem that your guinea pig may have in the future.
Corneal Ulcers in Guinea Pigs
Sometimes eyes get scratched or irritated by something in your guinea pig's cage like hay or bedding or even after a struggle with another guinea pig.
These scratches or irritations can cause an injury called a corneal ulcer. A corneal ulcer is a defect in the layer of your guinea pig's eye known as the cornea and it is painful. You may be able to see a bit of cloudiness or redness to the eye but more often than not your cavy may paw at it, keep it closed, or even rub it on the ground to signal that they have a problem. The pain from the ulcer may cause your guinea pig to stop eating and then even develop ileus.
Corneal ulcers can be treated with special prescription eye ointments from your exotics vet. Some of these ointments are antibiotics and some are made specifically to heal ulcers. If the ulcer is really large or hasn't healed after the use of some medications, your vet may draw some of your guinea pig's blood, centrifuge it, and use the serum that is produced as eye drops to help the ulcer heal. If the ulcer still hasn't healed, a special procedure called a grid keratotomy may need to be performed on the eye to encourage healing.
This procedure is done under anesthesia by your exotics vet.
Guinea Pig Eye Infections
Irritation or exposure to excessive amounts of bacteria or fungal spores can cause your guinea pig’s eyes to become infected. These bacterial and fungal infections can affect one or both eyes and need to be treated with the appropriate antibacterial or antifungal medications.
Your cavy may have hair loss around the infected eye, redness called conjunctivitis, discharge, swelling, and even hold the infected eye shut.
Your exotics vet may choose to treat the eye without obtaining a sample to culture first but if the infection does not resolve, or if you want to do the best thing possible for your guinea pig, a bacterial and/or fungal culture should be obtained. The culture will tell your vet exactly what kind of bacteria or fungus is growing around the eye and will allow them to pick the correct treatment for your pet. If your guinea pig has a lot of discharge from the eye and it is crusting shut, you can use a warm, damp cloth to gently clean it until you can see your vet. Sometimes just cleaning out the eye makes a world of difference to your guinea pig.
Overgrown Guinea Pig Teeth
Guinea pigs have teeth similar to those of a rabbit called front teeth called incisors. The roots of these incisors can grow into a pathway between the nose and the eyes, called the nasal-lacrimal duct, and cause your guinea pig’s eyes to weep. An easy test to see if there is a blocked nasal-lacrimal duct is to use a fluorescein eye stain and wait to see if it leaks out of your guinea pig's nose.
Normal ducts flow through the nose and allow drainage from the eyes but if that duct is blocked or clogged, excessive drainage will occur from the eye.
Tumors in Guinea Pigs
Sometimes growths or tumors will unfortunately develop behind the eyes of guinea pigs. These tumors can cause an eye to bulge or swell as well as be very uncomfortable for your guinea pig. Sometimes X-rays will be used by your exotics vet to identify a tumor on the skull of your guinea pig. These X-rays may also need to be read by a radiologist before your vet can make a diagnosis. Unfortunately, not all abnormalities are visible on an X-ray so your vet may also recommend an MRI be performed on your guinea pig. This is not something many guinea pig owners pursue and it is also not something many veterinary hospitals can provide.
Plus, even if a diagnosis is made, there is typically no treatment for a tumor behind the eyes. Guinea pigs that are suspected to have tumors behind their eyes are often instead treated symptomatically and provided with hospice care.