What is it?
Eye infections may also be referred to as conjunctivitis, as infections often affect the soft tissue around the eye (the conjunctiva). Eye infections are usually caused by bacteria or viruses, with different types of infections being more common in some rodents than others.
Rats for example are prone to eye infections which usually accompany upper respiratory tract infections with mycoplasma and Corona Virus (sialodacryoadenitis virus) being common causes. Eye infections in guinea pigs however are most often associated with a type of chlamydia.
What causes it?
Eye infections can be caused by bacteria or viruses (and occasionally fungi), which can be spread between individual animals, for example in a pet store or breeding colony, or picked up in the environment.
Crucially, though, small mammals may also get an infection because of a foreign item that has embedded into the soft tissue around the eye (like a sharp bit of straw), and this is one of the most common underlying causes.
Other conditions can cause similar symptoms to an infection. For example, an allergy to bedding or hay can cause some animals to have watery, irritated eyes. Underlying dental disease can also cause eye problems, with problematic tooth roots pressing on nearby tear ducts. So, it is always best to get your pet checked out by your vet.
What animals are at risk?
Any animal can suffer from an eye infection. Rats and mice however seem particularly prone, with respiratory issues being common in these animals due to infection spreading easily between individuals in a colony.
Animals that are also kept in poorly ventilated cages with dusty bedding and high levels of ammonia (usually from their waste if it isn’t cleaned out regularly enough) are more prone to disease.
What are the clinical signs/symptoms?
Animals with an eye infection may show the following symptoms –
How is it diagnosed?
You should take your pet to the vet for an examination. Your vet will start by looking at your pet and may use an ophthalmoscope to study their eye in more detail. This tool helps to provide extra light and magnification. Examining the eyes of rodents can be tricky compared to cats or dogs though because they are much smaller and less likely to keep still!
Your vet may also apply some dye to the surface of your animal’s eye which can help to highlight any scratches or ulcers that could be causing their symptoms. Local anaesthetic eye drops can be useful if your vet suspects a foreign body in your rodent's eye and needs to remove it, like a piece of straw or eye.
In some cases, samples may need to be taken to send to the lab for analysis. Culture and sensitivity can confirm if a bacterial infection is present and what the most effective treatment might be, and the swabs may also be advised to check for viruses. Your vet will discuss the tests that they specifically recommend for your pet in more detail.
How can it be treated or managed?
Eye infections are usually treated with antibiotic eye drops or ointments, which will need to be administered regularly. Sometimes lubricants are also prescribed to keep your pet’s eye comfortable if there is a scratch or corneal ulcer present. Anti-inflammatories may also be prescribed as a type of pain relief if your pet is uncomfortable.
Can it be prevented?
Whilst there is no sure-fire way of stopping eye infections altogether the following measures can help to reduce the risk of both eye and respiratory problems –