Most eye issues are emergent:
Eye(s) is swollen, cannot open, squinting, excessive blinking, bleeding, bulging, painful, popping out or prolapsed, sudden blindness of one or both eyes, Glaucoma-related concerns, pupils are different in size, lacerated eye, foreign object in the eye, excessive tearing.
Unless your pet has been examined and treated for a known eye issue (and even under a doctor's care when changes have occurred or your pet is painful), most concerns about your pet's eyes are emergent. There are a number of conditions that require a doctor's examination to determine the care and treatment needed for your pet. Here are a few eye issues that are seen in the veterinary emergency room:
Swelling/Inflammation of the eye(s):
Unlike inflammation that occurs throughout most of the body, inflammation in the eyeball becomes instantly serious. There is no room for expansion in the eyeball, and inflammation can quickly progress to blindness.
Retinal hemorrhage is defined as the abnormal bleeding of the blood vessels in the retina, the membrane in the back of the eye. Symptoms include inflammation, or a cloudy or red eye. The following problems can cause retinal hemorrhage:
- Coagulation problems (rat poisons)
- High blood pressure
- Immune-mediated diseases
- Fungal disease
The gradual onset of blindness is not an emergency unless you notice additional symptoms such as red, painful eyes, cloudy corneas, or swelling. Sudden blindness in dogs or cats, on the other hand, is an emergency. Among the conditions your veterinarian will consider as causes for sudden blindness are retinal detachment, brain tumor, trauma, poorly regulated diabetes, loss of blood flow to the brain, and high blood pressure. Cataracts can cause blindness, but they tend to develop slowly and cause a visible cloudiness of the lens.
Small dogs with large eyes and flat faces (brachycephalic dogs) are most likely to have eyeballs prolapse or pop out. With small dogs, the problem is often that the eyelids get caught behind the globe. With large dogs with normal-sized eyeballs, prolapse can also occur, and when it does, it is usually more severe because the optic nerve is generally stretched to the point of blindness. Prolapse can be caused by trauma or by any extreme increase in pressure within the head. Prolapse can lead to blindness or crossed eyes if muscles are stretched beyond their ability to contract back into position. Cover your pet's eye with a moist, cool, clean cloth and take him or her to the veterinary clinic immediately.
If tears suddenly begin spilling down your pet's face, there may be a foreign body in the eye that the tears will automatically flush out, or there may be a serious problem that requires veterinary care. For example, grass awns can get caught under eyelids where they act like foreign bodies causing pain and damaging the cornea. Tearing is also caused by grass awns, and other material, suddenly blocking the tear ducts so that tears which normally flow through the duct (nasolacrimal canal) and out the nose, now flow down your pet's cheeks. Corneal lacerations cause sudden tearing, perhaps because of the pain. Infections and cancers also cause tearing.
If one pupil is a different size than the other, the first thing your veterinarian will do is determine whether one is abnormally large or whether one is abnormally small. Then, your veterinarian will run laboratory tests and measure the eyeball pressure. Your veterinarian will look for problems caused by infection, cancer, trauma, old age, inflammation, or drugs. This is a medical emergency if it happened suddenly.