Most aging dogs will experience a decrease in both their visual as well as hearing abilities. When this loss occurs slowly, the dog is actually able to adapt and increase his or her dependence on the other senses to balance out the loss of vision or hearing. In this way an elderly dog can easily live a very happy and relatively normal life even with complete hearing or vision loss. Of course there are some modifications that owners need to make, especially with regards to safety issues for these dogs, but there is no need to feel sorry for your dog or believe that they feel the loss of these senses the same way that humans would.
Many of the vision and hearing loss conditions in dogs are inherited and are more evident in particular breeds. Testing the hearing and vision of the breeding pair is recommended in breeds with known problems, however in cases where the condition does not develop until the dog is older he or she may have already been used in breeding programs. When this occurs a reputable breeder will contact all puppy owners and notify them of the presence of the condition. A reputable breeder will also immediately remove the affected dog from breeding programs as well as any siblings of the dog if the condition is hereditary.
Progressive Retinal Atrophy (PRA)
Progressive Retinal Atrophy is an inherited condition where the lenses of both eyes are affected equally. All dogs with PRA will eventually become fully blind, although how long this takes and how early the symptoms begin to develop varies from breed to breed. It is a recessive genetic condition, which means that both of the parents have to carry the gene for the condition in order for the puppies to develop the vision problem. All puppies born from these crossings will carry one half of the genes needed for their offspring to also inherit the condition, but not all the puppies will exhibit the symptoms. This is what makes recessive genetic problems so difficult to eliminate from the breeding lines. New DNA tests in some breeds can identify the genetic precursors to the condition and are used by breeders trying to breed this condition out of their lines.
PRA is non-painful to the dog and he or she typically starts to show difficulty in seeing at night, more commonly called night blindness. The dog's pupils may appear dilated much more than normal and the eyes may have a slight sheen to them, similar to the early stages of cataracts.
In some new tests antioxidant supplements have been shown to slow the progressive damage to the retina and allow the dog a slightly extended time of sight. Exactly how beneficial antioxidant supplements are across all breeds and dogs is unknown, but early research shows it is most beneficial when started at the first signs of PRA.
Cataracts can be found in one or both eyes and result in an opaque color to the eyes and loss of vision. Cataracts are actually a cloudiness of the lens, which over time prevents any functioning of the eye. Some cataracts may not require surgery, especially if they only affect a smaller area of the lens or are only in one eye.
Cataracts are often inherited and are more problematic in specific breeds of dogs. Some of the breeds most often associated with this vision problem include the:
American Cocker Spaniel
However any dog at any stage of life can develop this condition. Cataracts can be surgically removed and an artificial lens implanted, followed by drug therapy. There is no other cure for cataracts and since eye surgery is very delicate it is often not completed on very elderly dogs or those dogs with other vision problems such as PRA.
Conjunctivitis is not a vision impairment on its own, but the redness and irritation caused by the inflammation can result in scarring on the eye itself, leading to vision problems. It can include issues stemming from objects imbedded in the eye or the eye tissue, clogged tear ducts, malformations of the eye or eyelids or bacterial or viral infections of the eye. Common symptoms include excessive tearing, rubbing and scratching of the eye as well as a thick discharge and redness.
Treatment for conjunctivitis includes removing any and all foreign objects or debris from the eye, correcting any malformation of the eye or eyelids with surgery and antibiotic lotions and drops to help the eye repair and heal.
Perhaps the greatest cause of non-inherited hearing loss is chronic or untreated ear infections. Dogs with lots of hair in the inner and outer ears, excessive wax production, and dogs that have ears covered by the outer ear are at greater risk for infections. Any type of closed ear such as those seen on Labradors, Hounds, Setters, Pointers, Spaniels and Newfoundland and Great Pyrenees breeds are the most problematic.
Keeping the dog's ears dry after bathing or swimming, routinely checking the ear and cleaning the wax out of the outer ear is the best prevention. For ears that have infections flushing out the ear and applying drying and antibacterial solutions combined with oral antibiotics prescribed by your vet is usually all that is needed.
Chronic ear infections can lead to other problems however, so early treatment and good, routine ear care is essential to prevent any long term hearing loss or damage to the ear itself.
There are different types of hereditary deafness in dogs, some which are present at birth and others that develop later in life. Generally most inherited deaf conditions are noted in breeds such as Doberman Pinschers, Bull Terriers, Australian Shepherds, Dalmatians, Shetland Sheepdogs and Border Collies. Often the early detected varieties of hereditary deafness are most commonly found in white dogs, especially those that have white coats and blue eyes or parti-colored eyes. Other coat patterns that are associated with full or partial hearing loss include the merle coat variety and piebald or white and brown or black coats.
This type of condition is not painful to the dog and most dogs adjust very well to hearing loss. Teaching hand signals and visual commands as well as ensuring that the dog is always either in a fenced yard or on a lead for his or her own safety is important.