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Inherited Disorders

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Cardiomyopathy

Dilated cardiomyopathy (DCM) is one of the most common acquired heart diseases in dogs. DCM is a disease of the heart muscle ("cardio" – heart; "myo' – muscle; "pathy" – disease) in which the muscle (myocardium) of the lower pumping chambers (ventricles) loses its ability contract normally. DCM most commonly affects the left side of the heart (the side that receives blood from the lungs and pumps it to the body) – specifically, the left ventricle. Since the myocardium cannot pump blood out of the left heart effectively, blood begins to "back up" within the left side of the heart and within the pulmonary veins that feed into the left heart. This leads to an enlargement of the heart in an attempt to compensate for the ineffective pumping.


As blood "backs up," left-sided congestive heart failure (CHF) or pulmonary edema (fluid within the lungs) develops. This is not a feature exclusive to DCM, but is a common feature of many types of left-heart disease.

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Cherry Eye

Prolapse of the Tear Gland of the Third Eyelid

The normal canine eye receives its tear film from two lacrimal (tear-producing) glands. One gland is located above the eye, and the other is found within the animal's third eyelid. The gland of the third eyelid contributes a significant portion of secretion to the tear film.

In the smaller breeds -- especially Boston terriers, Cocker spaniels, bulldogs and beagles -- the gland of the third eyelid is not strongly held in place. The gland prolapses (slips out) to where the owner notices it as a reddened mass. Out of its normal position, the gland does not circulate blood properly and may swell.

Treatment - Removal of the Gland

Historically, the prolapsed gland was treated like a small tumor and was simply removed. That was before the full significance of the gland was realized.

If the third eyelid's tear gland is removed, it cannot be put back in place. If the other tear gland (the one above the eye) cannot supply adequate tears, which is not an uncommon phenomenon in older small breed dogs, then the eye becomes dry and uncomfortable. A thick yellow discharge results and the eye develops a blinding pigment covering for protection. This condition is called simply dry eye, or more scientifically keratoconjunctivitis sicca, and daily medical treatment is required to keep the eye both comfortable and visual. Not only is dry eye uncomfortable for the pet, its treatment is often frustrating and time-consuming and there is expense involved. We would like the dog to maintain the greatest amount of tear producing tissue possible, thus removing the gland for cosmetic reasons is not an acceptable treatment method.

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Entropion

Entropion is an uncomfortable or painful condition in which the animal's eyelids roll inward, allowing the eyelashes (or other hair) to rub against the cornea and irritate it. The upper and/or lower eyelids can be involved, and the condition can occur in either one eye or both.

Signs

An animal with entropion will squint and have an excessive amount of tears coming from the affected eye. Some animals will be sensitive to light and will rub at their eyes, particularly when they're outside. Some animals will produce a mucous-like discharge from the eyes. Flat-faced dog/cat breeds, with entropion that involves the inside corner of the eyes, may not show any discomfort -- simply because of their facial structure.

In some animals, entropion is never more than a minor annoyance, but in others it can cause painful ulcers and erosions that cause scarring and affect vision. That level of entropion needs surgical correction.

Causes

While any dog can have entropion, there is often a genetic factor. When caused by genetics, entropion can be seen well before a dog's first birthday. Predisposed dog breeds include the Boxer, Bull Mastiff, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Chow Chow, Cocker Spaniel, English bulldog, Golden Retriever, Great Dane, Irish Setter, Irish Setter, Labrador Retriever, Poodle, Pug, Shar Pei, Springer Spaniel, and St. Bernard. Selective breeding for specific traits (e.g., skull formation, skin folds on the face, and prominent eyes) are thought to be contributing factors to genetic causes, but are most likely not the only genetic base. Selective breeding may have simply exaggerated entropion in breeds that were already prone to it.

Entropion can also occur as a secondary condition resulting from scarring of the eyelid, infection, corneal spasms and pain, trauma, or nerve damage. Sometimes it happens after the eyelids lose their normal neurologic function.

Treatment

Medical treatment with antibiotic ointments can decrease damage to the cornea, but it can not resolve the entropion itself. To fix the eyelid, surgery is needed.

If the entropion is significant enough to warrant treatment, the excess skin of the outer lids can be removed in a simple surgery called blepharoplasty. (Essentially, this is plastic surgery, so you can tell everyone your pet is having "his lids done."). Excess skin that causes skin folds is also removed, and the eyelids are tightened. Typically the entropion does not return after surgery, unless the case is quite severe. (Recurrence is more common in Shar Peis, due to the breed's excessive facial skin folds.) The sutures should be removed in about 10 to 14 days. Some dogs will need to wear an Elizabethan collar to prevent them from rubbing at their sutures. Young puppies generally only have a minor procedure called lid tacking, rather than the full blepharoplasty. Permanent surgery like the blepharoplasty isn't typically done in puppies who are less than 6 months old, because it's not possible to predict what the (adult) head conformation will be, and the full surgery may not be needed. In lid tacking, temporary sutures are used to roll out the eyelids, and keep the puppies' eyes healthy until these puppies mature and grow into their adult facial features. Entropion can be seen in Shar Peis as young as two or three weeks old, and these Shar Pei puppies do very well with the temporary eyelid tacking.

If the animal has corneal ulcers, those will need to be treated too. Untreated corneal ulcers may scar excessively, impairing vision. Treatment will reduce the incidence of scarring. Treatment usually involves the use of antibiotic ophthalmic ointment. (To administer ophthalmic ointment, place your thumb directly below the eyelid and very gently push, which will cause the lower eyelid to pull away from the eye. Put the ointment in the opened lower lid.)

The sutures should be removed in about 10 to 14 days. Some dogs need to wear an Elizabethan collar to prevent them from rubbing at their sutures.

Dogs with the inherited form of entropion should not be used for breeding.

Prognosis

Prognosis is excellent, if surgery is performed before the cornea is damaged. If the cornea is damaged, then the prognosis depends on the type and severity of damage.

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Progressive Retinal Atrophy

Progressive retinal atrophy, or PRA, is an encompassing term used to describe a group of canine retinal degenerative disorders that share similar clinical features, yet have a variety of different causes. The most common early clinical sign of PRA is loss of dim light (night) vision followed by deterioration of bright light (day) vision over a period of months to years. The age of onset and rate of progression of vision loss can be quite variable, although within given breeds, there is some degree of uniformity. In general, it appears that earlier onset vision loss is accompanied by a more rapid progression of vision loss.
What is the cause?

PRA is a genetic disorder. Several specific genetic defects have been described that account for the disorder in various breeds. PRA is most commonly diagnosed in purebred dogs, but the condition can also be seen in mixed breed animals.
Treatment/Management/Prevention:

Specific: None

Maintain a safe living environment for dogs with impaired vision. Quality of life can be enhanced by environmental modification and modifying activities to those based upon sound and smell rather than vision.

Preventive Measures: Avoid breeding affected dogs or parents of affected dogs.

DNA testing for PRA is available for an ever expanding number of breeds and can distinguish between affected, carrier and normal animals. This knowledge is of substantial benefit to breeding programs.

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Sub-Aortic Stenosis

Subvalvular aortic stenosis (SAS) is one of the most important congenital malformations of the canine heart and continues to frustrate breeders of many large breed dogs. The disease consists of a congenital defect within the left side of the heart that leads to outflow obstruction, increased systolic pressures and subsequently heart failure.
Clinically:

Congenital SAS is most common in North America among larger breeds, including the Newfoundland, Boxer, German Shepard, Golden Retriever and Bull terriers. Other large breeds, such as the Rottweiler, Somoyed and Great Dane, also may be overrepresented. Affected dogs are asymptomatic and have a soft murmur. Murmurs in dogs with mild cases of SAS are best detected after brief exercise. More severely affected dogs may have hind limb weakness, syncope (passing out) or left sided congestive heart failure. Sudden death without premonitory signs is very common.
Diagnosis:

SAS is diagnosed based on a thorough physical exam, history, radiographs and echocardiogram.
Treatment /Prognosis:

Treatment consists of surgical intervention, medical management and supportive care. The prognosis and management of dogs depends on severity of the disease.
 

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Von Willebrand's Disease

Most people are familiar with hemophilia A, an inherited blood clotting defect in human beings affecting only male children. Most people, however, are not as familiar with von Willebrand's disease and hear of it for the first time when they ask questions about breeding their dog. Von Willebrand's disease is also an inherited blood clotting defect and breeds at high risk should be screened before being allowed to breed.