Rat Squinting or Keeping One Eye Closed: Pain, Injury & Care

Quick Answer
  • A rat that is squinting or keeping one eye closed is often showing eye pain, not a minor habit.
  • Common causes include a scratch or corneal ulcer, bedding or dust irritation, conjunctivitis, trauma from cagemates, eyelid swelling, or excess porphyrin linked with stress or illness.
  • Same-day veterinary care is wise if the eye is red, swollen, cloudy, has discharge, or your rat is rubbing at it.
  • Do not use human eye drops unless your vet specifically tells you to. Some medications can worsen an ulcer or delay healing.
  • A basic exotic-pet exam with an eye check often falls around $80-$180 in the U.S., while staining, medication, and follow-up can bring total care into the low hundreds.
Estimated cost: $80–$350

Common Causes of Rat Squinting or Keeping One Eye Closed

Squinting, blinking more than usual, or holding one eye shut usually means the eye is irritated or painful. In rats, common causes include a corneal scratch or ulcer, a bit of bedding or hay dust trapped under the eyelid, conjunctivitis, and trauma from grooming, climbing, or a cagemate. Even a small surface injury can make a rat keep the eye tightly closed.

Rats can also develop reddish-brown staining around the eye from porphyrin, sometimes called "red tears." This is not the same as blood. A small amount can appear with stress, but heavier one-sided staining together with squinting suggests the eye itself may be irritated or painful. Respiratory illness and general stress can also increase porphyrin production, so eye signs sometimes overlap with broader illness.

Less common but important causes include eyelid infection, abscesses near the eye, deeper trauma, or a problem behind the eye that makes the eye bulge or become hard to open. If the eye looks cloudy, swollen, very red, or suddenly different from the other eye, your vet should examine it soon. Eye disease can progress fast in small mammals, and waiting can turn a treatable irritation into a more serious injury.

When to See the Vet vs. Monitor at Home

See your vet immediately if your rat has severe redness, marked swelling, cloudiness, bleeding, pus-like discharge, a visible cut, a bulging eye, or cannot open the eye at all. The same is true if your rat is pawing at the face, seems very painful, stops eating, becomes quiet, or has breathing changes along with eye discharge. Eye injuries and ulcers can worsen quickly, sometimes within a day.

A short period of monitoring may be reasonable only if the eye opened again after a brief irritation, your rat is acting normal, and there is no redness, swelling, cloudiness, or ongoing discharge. Even then, monitor closely for the next 12 to 24 hours. If squinting returns, porphyrin builds up again on one side, or the eye looks different from the other eye, book an appointment.

Do not try leftover pet medications or human eye products at home unless your vet has told you exactly what to use. Some eye drops, especially steroid-containing products, can be harmful if there is a corneal ulcer. Because rats are small and eye changes can be subtle, it is safer to have your vet confirm whether this is irritation, infection, or an injury.

What Your Vet Will Do

Your vet will start with a careful history and physical exam, then look closely at both eyes for redness, discharge, swelling, eyelid injury, foreign material, and differences between the two eyes. They may ask about bedding type, cage cleaning products, recent introductions, fighting, respiratory signs, and whether you have seen porphyrin around the eye or nose.

A basic eye workup often includes magnified examination and fluorescein stain, a dye test that helps show scratches or ulcers on the cornea. Your vet may also assess tear film, eyelid movement, and whether the eye is painful or protruding. In a very wiggly or painful rat, gentle restraint or light sedation may be needed for a safe, accurate exam.

Treatment depends on the cause. Your vet may prescribe lubricating drops or ointment, an antibiotic eye medication, pain control, or treatment for an underlying respiratory or skin issue. If there is an abscess, deeper injury, or a problem behind the eye, your vet may recommend imaging, sedation for flushing or cleaning, or referral for advanced care. Follow-up matters because a rat may look more comfortable before the eye is fully healed.

Treatment Options

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$80–$180
Best for: Mild squinting with a stable, otherwise bright rat when your vet suspects surface irritation, early conjunctivitis, or minor trauma.
  • Exotic-pet exam
  • Eye inspection and eyelid check
  • Fluorescein stain if available in general practice
  • Basic topical lubricant or antibiotic if indicated by your vet
  • Home-care instructions and short recheck plan
Expected outcome: Often good if the problem is superficial and treated early. Many mild irritations improve within a few days, but ulcers can worsen if not rechecked.
Consider: Lower upfront cost, but fewer diagnostics may miss a deeper ulcer, abscess, or problem behind the eye. You may need a follow-up visit if signs do not improve quickly.
Most Common

Recommended Standard Treatment

$180–$450
Best for: Most rats with persistent squinting, one eye held closed, redness, discharge, or suspected corneal injury.
  • Exotic-pet exam
  • Fluorescein stain and focused ophthalmic exam
  • Pain medication
  • Topical eye medication selected by your vet
  • Assessment for respiratory disease, trauma, or cagemate injury
  • Recheck visit in several days to confirm healing
Expected outcome: Good to fair, depending on the cause. Early treatment improves comfort and lowers the risk of corneal scarring or worsening infection.
Consider: More complete than conservative care and often the best fit for painful eyes, but total cost is higher and some rats still need sedation or referral if the exam is limited.

Advanced / Critical Care

$400–$1,200
Best for: Severe pain, cloudy eye, bulging eye, deep ulcer, facial swelling, suspected abscess, recurrent cases, or rats not improving with first-line treatment.
  • Sedated eye exam or flushing
  • Skull or dental imaging if a deeper cause is suspected
  • Culture or cytology in select cases
  • Abscess treatment or wound repair
  • Specialty ophthalmology or exotics referral when available
  • Hospitalization, injectable medications, or surgery for severe trauma
Expected outcome: Variable. Some rats recover well with intensive care, while severe trauma or deep infection can leave scarring or require long-term management.
Consider: Most thorough option, but it involves the highest cost range, more handling, and sometimes anesthesia or referral travel. It is usually reserved for complicated or urgent cases.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Rat Squinting or Keeping One Eye Closed

Bring these questions to your vet appointment to get the most out of your visit.

  1. Does this look more like a corneal scratch, infection, irritation, or trauma?
  2. Do you recommend a fluorescein stain or any other eye tests today?
  3. Is there any sign of an ulcer, foreign material, or damage behind the eye?
  4. What medications are safest for this eye, and are there any drops I should avoid?
  5. How should I give the eye medication to a rat safely at home?
  6. Should I separate my rat from cagemates while the eye heals?
  7. What changes would mean the eye is getting worse and needs an urgent recheck?
  8. What cost range should I expect if this does not improve and needs sedation, imaging, or referral?

Home Care & Comfort Measures

Until your rat is seen, keep the cage clean, low-dust, and calm. Remove sharp hay stems, dusty bedding, and anything that could poke the face. If cagemates are grooming too roughly or there has been fighting, temporary separation may help prevent more trauma. Make sure food and water are easy to reach, since a painful eye can make a rat less active.

You can gently wipe away discharge on the fur around the eye with clean gauze or a soft cloth dampened with warm water, but do not press on the eyeball. Do not try to pry the eyelids open. Avoid over-the-counter human redness-relief drops, leftover antibiotics, or steroid eye medications unless your vet specifically prescribed them for this rat and this eye problem.

Watch for worsening redness, swelling, cloudiness, more porphyrin on one side, reduced appetite, or rubbing at the face. If your vet prescribes eye medication, give it exactly as directed and finish the course unless your vet changes the plan. Rechecks are important because the eye may look less squinty before the surface is fully healed.

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