Dog’s eyes are similar to our eyes, and they can succumb to similar diseases and damage as ours too. One clear difference between dog’s eyes and our own is that dogs have an extra eyelid – an inner one. You’ll see this sometimes when your dog is asleep – a pale membrane which rises up from the inner lower corner of the eye. This is additional protection for the eye, and is rapid to deploy when in an emergency.
Dog Eye Anatomy
Eyelids in dogs
Your dog has two external eyelids of folding thin skin – one top and one bottom, the same as we do. The eyelids are for eye-protection, but also to spread lubricating and washing tears over the eyeball. Tears are comprised of oil, water and mucus, which are produced by glands around the eye and normally drain into the nose. The two eyelids blink as a protective reflex when the eye may be in danger of impact.
A dog’s third eyelid is called the nictitating membrane, palpebra tertia or ‘haw’, and is used to protect the eye when under threat from undergrowth or other objects. This can be partly or completely raised if the eye is irritated due to inflammation or a foreign object lodged in the eye; the inner eyelid is also shut when your dog is asleep or unconscious. The haw also deposits a significant quantity of tears directly onto the eyeball, which have an anti-bacterial and anti-fungal action; this also acts as a well-lubricated ‘windscreen wiper’ for debris on the eyeball.
People and primates in general are unusual in not having a third eyelid – most animals do have a third eyelid for extra eye lubrication and protection.
Eye problems in dogs
Eye discharges
Rheum, or ‘sleep’ that appears in eyes when rousing after a sleep is merely dried-up tears and debris from the time the eyes aren’t blinking. Blinking removes the tears and debris, but during sleep the discharge dries out and appears as a lump in the corner of our eyes.
If the ‘sleep’ seems dry and sandy then it is possible that a dry-eye problem exists. If the rheum is gunky or sticky then it could be that allergies are to blame. Any dog eye irritation or infection will result in more mucus production, and therefore more discharge from the eye. Excessive discharge leads to large quantities of visible rheum in the corners of your dog’s eyes; these can be gently removed by wiping with a warm damp cloth. Consult your vet if excessive discharge is persistent!
Yellow, green or white discharges, redness in the whites of the eyes (the sclera), reddened inner eyelid or swollen outer eyelids could all be problems needing immediate veterinary attention.
Conjunctivitis (‘Pink Eye’)
The conjunctiva is a protective membrane which covers the white of the eyes and continues over the coloured iris, right up to the cornea (the lens-covering membrane). It also covers the inner faces of the eyelids.
Conjunctivitis is inflammation or irritation of this membrane, and is fairly common in dogs. This is usually easy to treat with eye-drops, antibiotics or antihistamines; surgery on the dog is sometimes needed.
Conjunctivitis can be caused by allergies, bacterial infection, or foreign bodies stuck beneath an eyelid. It can also be a viral infection – both eyes are often affected simultaneously if this is the case. Injury, a blocked tear-duct, glaucoma, dry-eye (perhaps from diabetes) or parasites can also cause conjunctivitis. Keep your dog up-to-date with vaccinations to reduce the chances of them developing conjunctivitis.
Symptoms of conjunctivitis include redness of the eye, swelling of the eye-lids, eye-irritation and clear or green eye-discharge. Squinting, rubbing of the eye and unusually frequent blinking can also be symptoms. It can be difficult to spot, as sometimes they eye hardly looks pink at all!
Some breeds are more susceptible, such as Pugs, Pekinese, Poodles and Cocker Spaniels. Check-ups for conjunctivitis in these breeds are advised, even though no symptoms may be present.
Glaucoma
Glaucoma is caused by a deterioration of the optic nerve in the eye, caused by an increase of pressure inside your dog’s eyeball. The pressure increases when normal fluid outflow is impaired as a result of infection or physical damage to the eye.
This sometimes excruciating condition gets worse over time and is serious; it is an inherited weakness in some breeds and can lead to complete blindness in as little as a year. Regular check-ups at the vet’s may lead to early diagnosis; treatment to retain vision and to reduce pressure is needed, but there is no cure for the optic nerve damage caused by glaucoma. Treatment will also help prevent the condition continuing into the other eye.
Symptoms include signs of poor vision (in one or both eyes), redness of the blood vessels in the whites of eyes, smaller or large eyeball size or cloudy-looking eyes. If any one of these symptoms is noticed, please see your vet.
Entropion
Entropion is when your dog’s lower or both external eyelids turn inwards. This leaves the eyelashes rubbing the cornea and conjunctiva of the eye and is very uncomfortable. This problem can easily lead to eye damage and even blindness; make an appointment with your local vet! Surgery is usually needed to correct entropion, but eye-drops can succeed in correcting the problem at least for a while.
Cataracts
A cataract is opacity in the lens of the eye, causing blurry vision. These will develop in size and density with time, leading to increasing sight problems for your dog. Cataracts form because of disease, trauma or just old age; some breeds are predisposed to cataracts at any age. Breeds such as Smooth Fox Terriers, American Cocker Spaniels, Havanese, Bichon Frise, Silky Terriers, Miniature and Standard Poodles, Miniature Schnauzers, and Boston Terriers may more easily develop cataracts.
A high incidence of cataracts is caused by diabetes; about 80% of diabetic dogs will develop cataracts within a year or so of diagnosis. Glaucoma can result if a cataract detaches from the lens and blocks fluid drainage; if the cataract begins to dissolve this can lead to inflammation of the eye.
Treatment of cataracts is similar to that on people – surgical replacement of the lens with a plastic one. Old dogs can develop a cloudiness or grey colouring to their eyes called nuclear sclerosis; this is not as troublesome for your dog as cataracts; treatment is not usually recommended. Always see your vet if cloudiness is seen, however.
Hyphema (blood-filled eye)
This dramatic-looking problem can be caused by injury to the eye, retinal detachment, intraocular neoplasia (a benign tumor or a malignant tumor), high blood pressure or being shot in the eye or neck. Obviously you will be keen to see the vet, who should be able to find the cause.
‘Cherry Eye’ in young dogs
This is a colloquial term describing the prolapse of the third eyelid gland from its normal position; it normally appears only in dogs under 18 months old. We see the pink gland raised from its normally invisible placement behind the third eyelid at the lower part of the eye. The gland may be red and inflamed. This gland is very important for eye lubrication and protection as it produces up to half of tears for the eye. If it is out-of-place then tear production will reduce, which could then cause conjunctivitis or dry-eye.
Surgery can be carried out to re-position and re-attach the gland, although sometimes the problem corrects itself with antibiotics and steroids. The third eyelid can sometimes be relocated successfully using a diagonal-toward-snout closed-eye massage of the affected eye.
Scrolled cartilage or cartilage inversion of the third eyelid can look exactly like pink-eye, and can also be corrected by surgery.
Sudden acquired retinal degeneration syndrome (SARDS)
This tragic problem can cause blindness immediately, or over a period of days or weeks. Symptoms include dilated pupils, plus similar symptoms to Cushing’s disease; the dog may have increased water consumption and urination, weight gain, confusion, restlessness, behavioural changes and lethargy. Causes are unknown, and there is no effective treatment or cure.
Progressive retinal atrophy
This is an inherited (genetic) group of conditions which displays as progressive blindness; this is due to the retina losing function in the rods and cones that make it up. As the retina rods fail first, the first symptom may be night blindness. There is no cure or effective treatment.
Physical Injury to dog’s eyes
When running or sniffing through undergrowth, your dog may sustain a scratch or poke to their eye. The sclera (white) and cornea (lens cover) are the outer surfaces most likely to be injured in a light collision with a thorn or twig. Alternatively, fighting (or playing rough) with another dog may result in a tooth-scratch or claw-swipe to your dog’s eye.
Your dog will squint and rub their eye if they have an injury, and the eye may be inflamed, red and moist from tears. Take your dog to the vet; they will probably prescribe antibiotic eye drops or atropine ointments to help heal the injury and to prevent infection.
Caring for your blind dog
If your dog becomes blind or partially-sighted, then there are measures we should take to make life easier for them. Sight is only one of a dog’s senses; it is an important one but your dog can still thrive and be happy without seeing. Smell, hearing and touch will become more sensitive to your dog, and this will help them negotiate their environment.
In the home
To help your dog negotiate your house and garden, keep everything the same. They will soon become aware of where the furniture and doorways are by memory, smell or the texture of your flooring – as well as touch (!). Sometimes it is difficult to tell that a dog is blind from their movements around the house; they get to know the layout so very well. Carpets are part of the scenery, so don’t move rugs around or put new ones down without acclimatising them to it; your dog will feel the difference and become confused, at least for a while.
A radio or television, a ticking clock, a ‘fridge or a fish-tank can be audible landmarks for your dog – leave them on if that makes it easier for your dog. A radio quietly on by their bed may make a safe dozing place easier to locate for them! Any changes you need to make to your dog’s home should be introduced gradually; lead them around the new items a few times to spot the differences without suffering collisions. Try a strongly-textured mat on either side of a step or kerb so that your dog will recognise the hazard ahead. Doors that are usually left open should not be closed; need I say more!
Furniture and food bowls
These should be kept in a fixed place, perhaps helped to remain in place by using a bowl-stand or anti-slip bowls. Sharp edges to tables, glass shelves and other furniture can be softened with padding; make sure your dog can’t wander into a wood-burner or fireplace and tidy away any trailing cables and any other scattered objects.
Outside at home
Outside, trim back hedges and trees to avoid dog injury, and fill any holes they may accidentally slip into; barriers around a fish pond or swimming pool are a must!
When walking your dog, it’s probably safest to always use a lead and to make your position obvious to them. A jangly key-ring or something that is attached to you will let them locate you more easily. It may be a great idea to take your dog out in a stroller or carrier (if they are light enough) from time to time; that way, you can easily travel to new areas with exciting new smells and sounds. Trips by car, train and bus are not out-of-bounds as long as your dog’s lack of sight is allowed for. We have a range of strollers – click here to see a few.
Ramps instead of steps might be better for negotiating changes in level, as long as your dog can’t fall off the side; in special cases (e.g. car ramps) you can guide them up or down the dog ramp. For a blind dog, jumping is literally a leap into the unknown, and extremely hazardous.
Your routine
Your dog knows your routine, and they will feel most reassured if you keep it consistent. Times for going out for a walk or food time will be anticipated, and your dog will prepare for it in plenty of time. Being around at known times means that they can sleep soundly knowing you will be back in a while and your dog won’t be alarmed by someone entering the house at odd times; they may not realise that it’s you if it’s an unusual time to return.
Other ideas for your blind dog
In the home
A second dog in the house could be a boon to your disabled dog; your sighted dog may adopt the role of protector for your blind dog. With a guide to help avoid hazards and offer reassurance, your sighted dog may be a great boost for the blind dog. The People’s Dispensary for Sick Animals (pdsa) published a great story of a blind dog and it’s sighted father coping in this way; click here to read it.
A safe and cosy bed area will reassure your dog that they are secure when after all, they can’t see that they are. Knowing that you are around the house involves making some noise so that your dog doesn’t feel deserted; talking to your dog regularly is good, as is wearing noisy shoes or slippers. Family (pack) and home (their den) are paramount to any dog; anything you can do to maintain that structure will be reassuring for your dog. Food and water are crucial too; a water-fountain is a great idea to help your pet find a drink easily by sound!
Out and about
A harness or dog-shirt with ‘Blind Dog’ printed on it may help when meeting other people on walks; your dog can’t know when someone is reaching out to stroke them – a surprise hand-on-head may end up with a nip. Julius makes a dog harness where the sides have removable velcro-attached labels, which can be custom-printed. A label like ‘Do Not Pet’ or ‘Blind Dog’ may help. Click here for Julius K9 harnesses; custom labels are available from there too.
Your partially-sighted dog may be called disabled, but they can still enjoy a full and happy life with us. Some imagination will go a long way to adapt your home to your blind dog, and many years of enjoyment can be gained from it.
