Dogs frequently suffer irritating eye inflammation at this time of year. The eyelids suddenly appear red and swollen and the animal may rub them frequently or keep the affected eye half-closed. The eye waters profusely at first, but the discharge may become more purulent if secondary infection occurs.
My dog has something in his eye
Most of these eye conditions are simply a reaction to pollen and dust blown by the strong drying winds that are common at this time of year.
The lining of the eyelids, the conjunctiva, reacts by becoming inflamed, and tears are produced in an attempt to wash the irritant substance away.
Simple treatments are often effective. Move the animal out of the wind, dust, and strong sunlight. A solution that is compatible with the tissues of the eye is made by adding a teaspoonful of common salt to 600ml of boiled water.
Keep this solution in the refrigerator and bathe the eyes 3 or 4 times daily. If the inflammation does not subside within 24 hours consult your veterinary surgeon.
Some animals, like their owners, are more sensitive to certain pollens. If your dog suffers from an allergic condition, avoid exercising it in areas of uncut native grasses.
A suddenly developing acutely painful eye should arouse suspicions of a more serious eye injury.
Animals pushing their way through long grass may get a grass seed lodged in the eye. It usually reacts by keeping the eye tightly closed and resists any attempt to open the eyelids.
Even if the owner is successful in opening the eye, it is often difficult to see the foreign body as it can be lodged in the many folds of the conjunctiva or may have worked its way between the third eyelid and the eyeball.
My dog scratched his eye
Injuries to the surface of the eyeball, the cornea, cause similar reactions and acute pain.
Dog scratches or wounds from sharp branches are the most common causes of corneal injuries. A bloodstained watery discharge from a tightly closed eye should always be treated as a sign of serious eye injury and should be investigated by your vet.
When the cornea is injured its blood supply is stimulated. The tissues become swollen, the blood vessels surrounding the area become engorged and a bluish opacity replaces the normal crystal-clear appearance.
My dog has an eye infection
Dogs with very prominent eyes, such as pugs, Pekinese, and Cavalier King Charles spaniels, are prone to develop corneal ulceration — an erosion of the surface of the cornea as the result of a bacterial infection. This condition requires vigorous treatment to avoid permanent damage.
The cornea is the remarkable structure that coats the front of the eye and which is normally totally transparent. This extremely tough yet clastic tissue is composed of four layers.
The outer layer, an epithelium, undergoes constant change, its components being replaced every seven days. This property of rapid cell division enables it to respond rapidly to injury and, fortunately, it is capable of very rapid repair. Its outer surface is kept perfectly smooth by the lubricants secreted by the tear glands.
The cornea is normally in a state of dehydration. Injury results in a rapid response — the cells of the cornea take up water and swell markedly. Blood vessels surrounding the cornea are stimulated and pour in white cells and the whole structure loses its transparency and becomes thickened and cloudy.
Injuries to the cornea commonly occur as a result of fighting. Cat scratches and puncture wounds cause intense pain and reluctance to open the eye in bright light. The cornea quickly becomes clouded and it is often necessary to sedate the animal in order to discover the true extent of the injury. The veterinary surgeon commonly uses a harmless dye to stain the surface so that any imperfection can be easily seen.
Grass seeds commonly lodge in the animal’s eye as it pushes through dry grass. The seed can be difficult to see as it often makes its way behind the third eyelid or nestles in the folds of the conjunctiva. The surfaces of the cornea can also be irritated by misplaced hairs of the eyelids or inwardly folded lids.
Infections of the cornea can occur quite suddenly and can threaten the sight of the animal if not treated promptly. These may occur as an extension of an infection of the conjunctiva, or as a result of corneal damage.
Infections of the eye can occur alarmingly quickly. A slightly weeping red eye one day may turn into an intensely inflamed, acutely painful condition the next.
Some bacterial infections are capable of producing an enzyme which helps to break down the normal cellular structure of the cornea. The surface becomes eroded and, if the process is not checked by vigorous early treatment, there is a risk of rupture and the escape of fluids from the interior of the eye.
A common problem in old animals is associated with the failure of the tear-producing or lacrymal glands. The surface of the cornea becomes dry and loses its bright, transparent quality. It is also prone to chronic infection and the owner must irrigate the surface of the eye with a solution containing normal saline and synthetic compounds to simulate the lubricating and protective substances of normal tears.