Although it is natural for most Yorkshire terriers to have a bit of tearing from their eyes, if it is extreme, the result is not only unattractive but also uncomfortable for the dog. There are ways to minimize tear stains making the Yorkie look and feel better. When your Yorkshire terrier's eyes tear too much, the resulting damp hair under its eyes becomes a prime breeding ground for yeast and bacterial growth. This dampness results in reddish-brown stains. [...]
Cataracts are one of the most common eye problems in dogs, and they show up in canines of all breeds and in animals both young and old. As with humans, the only successful treatment is surgery.
The word "cataract" literally is Latin for "break down," and refers to a problem that develops with the fibers in the lens of the eye. The disruption of these fibers causes the lens to become cloudy, reducing vision. There are several types of cataracts, which have different causes. All, however, result when the biochemistry of the eye (66 percent water and 33 percent protein), becomes out of balance. The end result is that too much water remains in the lens of the eye, while the percentage of insoluble proteins increases. The combination causes the cloudy white coating, loss of transparency and loss of vision characteristic of cataracts. [...]
Few eye problems cause more discomfort in dogs than the hereditary condition known as entropion. This is a problem that causes the eyelids to roll inward, pressing the eyelashes against the sensitive eye surface, and leading to pain, tearing and vision loss.
The lower lid is affected more often than the upper eyelid, although the condition can affect both. Entropion normally appears when the dog is young, before 1 year of age. Owners will notice their pet squinting, tearing excessively, avoiding bright lights and strong winds, and possibly pawing at its eyes or rubbing its face against the ground. The eyes also may appear red and irritated. As you can imagine, the pain of the lashes pressing against the sensitive cornea of the eye is significant. Over time, if the condition is not repaired, the cornea will be ulcerated and scarred, producing not only pain, but also reducing or destroying the dog's vision. Nerve damage also may occur within the eyelids and structures around the eye. [...]
Say the word "glaucoma," and people are more likely to think of their grandmother than their Great Dane. However, glaucoma also affects animals of all types, including dogs.
Glaucoma occurs as a result of increased pressure within the eye. Cells inside the eye produce a clear fluid, known as the aqueous humor, which feeds the tissues inside the eye, as well as keeping the eye in its proper shape. Normal eye pressure is maintained through a balance of fluid created by the eye and drainage provided by ducts within the eyeball and surrounding structures With glaucoma these drains become blocked, yet the eye continues to produce fluid, increasing the internal pressure. Over time, this can cause the eye to stretch and enlarge, causing pain and damaging vision. [...]
Microphthalmia is a disabling genetic condition that occurs when a dog's eyeballs are smaller than normal, severely restricting its vision. With this condition, the internal structures of the eye are abnormal as well, resulting in a prominent third eyelid and small eyes that appear to be recessed into the dog's eye sockets.
Microphthalmia is inherited in many dog breeds through recessive genes. It also can appear in puppies whose mothers received certain types of medication during pregnancy. Owners of affected dogs will notice that their eyeballs appear smaller than normal for the animal's breed, and there may also be noticeable signs of visual impairment. In fact, most dogs with the problem are either born blind, or else eventually become blind or severely visually handicapped. [...]
Among the many eye conditions that can affect dogs is one that isn't painful, but is nonetheless heartbreaking. Progressive Retinal Atrophy, or PRA, is a genetically inherited condition in which the eyes are basically "programmed" to go blind.
PRA can appear in any breed of dog, and is equally prevalent in purebred and mixed-breed animals. It's usually transmitted through a recessive gene, meaning two carriers of the gene must mate in order to produce an affected pup. The exceptions to this rule occur in Bull Mastiffs and Old English Mastiffs, where the PRA gene is dominant, so only one parent need have the gene in order to produce pups with PRA. Also, the gene is linked to gender in the Samoyed and Siberian Husky breeds. In these breeds, the disorder appears more often in males than females. [...]
Retinal dysplasia, or RD, is an inherited disorder in which the retina of the eye is malformed. To understand retinal dysplasia it's first necessary to understand the basics of the eye's anatomy. The retina itself is the nerve-containing structure in the back of the eye that takes in light and converts it into electrical signals. These signals are then transmitted to the brain via the optic nerve, and interpreted by the brain as vision. Formation of the eye in utero is a complex, multi-stage process that is closely tied to development of the entire nervous system.
There are three forms of retinal dysplasia. The first and least serious occurs when the two primary layers of the retina do not form together properly, creating folds in the inner retinal layer. In geographic RD there are larger areas where the retina is malformed in addition to the inner retinal layer. In the most severe form of the disease, the two retinal layers do not meet at all, resulting in retinal detachment, or separation, from the rest of the eye. [...]
If you notice your dog squinting and pawing at its eyes, or if the eyes are red, inflamed and watering heavily, a trip to the veterinarian is in order. It's possible in this case that your dog may have distichiasis, a condition that occurs when the eyelashes grow abnormally, placing them in direct contact with sensitive eyeball tissue. The hairs are often long and stiff and grow out of oil glands within the eyelids. In most cases there are multiple improperly grown hairs, and both eyes are affected. Also, even though dogs usually have no lower eyelashes, in cases of distichiasis both lower and upper eyelids can be affected. [...]
One of the more miraculous parts of the mammalian body is the retina, a structure that fits snugly and smoothly against the inside back wall of the eyeball. The retina is responsible for sending visual images to the brain via the optic nerve. Or, in other words, it acts as the "film" in the camera that is vision. When the retina becomes separated from the support tissue underneath (the choroid, which supplies the retina with blood and oxygen) it can no longer function and is termed "detached." If not treated promptly and properly, the affected animal will become blind, sometimes within a matter of days. [...]
We all know how painful it can be to have a single eyelash stuck in our eye. Imagine, then, the unending torment of an entire eyelid full of eyelashes turned inside out, with all of those lashes continually pressed against sensitive eye tissue.
This problem occurs in many breeds of dogs, and is known as eyelid entropion, or a rolling in of the eyelid. The condition is not only painful, but it also can cause ulcers or erosion on the cornea of the eye, resulting in scarring and reduced vision. [...]
In a normal eye the lens is clear and translucent, the better to perform its job of transmitting and focusing light onto the retina in the back of the eye. When disease, aging, or injury clouds and/or damages this lens, a variety of vision-related problems can occur.
One commonly recognized form of lens opacity is a cataract, which causes a cloudy film to gradually grow over the lens, obscuring vision. Most cataracts in dogs are genetically related. How old the dog is when cataracts appear and how severe they become depends largely on what type of breed is affected. [...]
Among the many hereditary eye disorders that can appear in your canine is an unusual condition known as an ocular coloboma. Colobomas are a congenital anomaly in which some of the structures of the eye are missing. This occurs when tissues fail to fuse and/or form completely while the puppy is still in the mother's womb. In ocular colobomas, for example, there is a visible black hole or cleft in the ocular nerve.
Colobomas also can be found in other structures within the eye, including the iris, choroid, ciliary body, eyelid, lens, and retina, where they again are present as a hole, split or cleft in the affected structure. [...]
One of the multiple eye disorders that can affect your dog is an inherited condition known as iris coloboma. With this condition, and for unknown reasons, development of eye tissues is incomplete in the womb. This causes the puppy to be born with a hole, split, or cleft in certain structures within the affected eye. In this case it's the iris, which is the colored portion in the front of the eye. Dogs with this condition will have a dark hole and/or an irregularly shaped iris, but their vision is usually not impaired. However, they may squint and be uncomfortable in bright light, since the coloboma prevents the iris from contracting normally upon exposure to light. [...]
Cataracts are one of the most well-known forms of eye disease, appearing as a cloudy or opaque spot that changes the lens of the eye and causes it to lose its translucence. Cataracts may be limited to a small section of the lens, or they may grow to affect the entire eye. Cataracts also can strike one or both eyes, depending upon the cause. If left untreated, cataracts inevitably end up costing the dog its sight.
Many breeds are prone to inherited cataracts, which can be passed along through both dominant and recessive genes. Inherited forms result in what are known as primary cataracts. [...]
Have you ever had an eyelash in your eye that caused that horrible scratching, itchy, and irritated sensation? Well how about having a whole eyelid full of eyelashes turned inward against your eye, it wouldn't be pleasant, would it?
That is exactly what dogs that have entropion are dealing with. This condition can be hereditary as well as caused by injury or disease. Entropion is common in many breeds of dogs, both purebred and mixed breed, and is one of the leading eye problems that puppies and dogs experience. Although it is most commonly noted on the lower eyelid it can also be present on the upper eyelid as well. In puppies the condition is usually noted very shortly after the puppy opens his or her eye and can be corrected at this time with a simple surgical procedure that pulls the eyelid down and stitches it to keep the eyelid in the correct, outward facing position. [...]