Genetics: Eye Problems

cataractsThe Havanese is generally a healthy long lived little dog. This does not mean he is perfect. Just like every other dog breed, the Havanese is prone to some genetic hereditary disorders. Like other breeds with a very small gene pool, some of these issues may be compounded and widespread. As the breed is still quite young in its rebuilding, some disorders are just now coming to light. If you take into account the other breeds that played a factor in the development of the Havanese, it stands to reason that the Havanese may have hereditary problems that are encountered in these and other similar breeds.

Of those we currently know about, Heritable Cataracts is the most significant hereditary disorder in the Havanese. Other heritable disorders that have been diagnosed in the Havanese include eye problems such as heritable cataract, cherry eye and excessive tearing; Mechanical, movement and structure related problems include Hip Dysplasia, Patella luxation, , Chondrodysplaysia , disk problems and Legg Perthes Disease. Problems of the major organs that have been identified are liver shunt and heart disease; Other heritable disorders are neurological disorders, thyroid deficiency, allergies, deafness and a short hair gene.

HERITABLE CATARACTS - At this time heritable cataracts is the most widespread of the genetic disorders in the Havanese. There is no clean line; all lines are affected. This is a somewhat unusual cataract. It cannot be defined as a Juvenile cataract though it may be early onset; it may also appear as late as 7 years of age. The most common age of diagnosis is 3 - 4 years of age. This cataract can show up in different forms. The most serious of these can show up as early as 10-15 months of age. While this type of cataract has the potential to progress to vision impairment or blindness; oftentimes, it has been noted in many Havanese, that these cataracts progress quickly and then may break up and improve somewhat.

A later onset cataract shows up between 4-7 years of age. This type tends to be slow growing, it can progress, though usually quite slowly but it also can break up in subsequent years. This type is much less likely to cause blindness and minimally impacts the vision. This heritable cataract appears to be a recessive gene where a dog must get the defective gene from both parents in order to become affected. At this time there is no test. Until a test becomes available, it is a wise precaution to get a puppy only from parents who have current certified eye exams. All Havanese owners are encouraged to annually eye test and certify their dogs whether they have companions or show dogs. The earlier the problem is diagnosed, the better chance there is of being able to treat it before blindness occurs. Senior cataracts occur in most breeds in old age. In a long lived, slow maturing breed like the Havanese, these are unlikely to show up before 9-10 years of age.

CHERRY EYE - is a swollen or prolapsed gland of the third eyelid. The gland protrudes and becomes irritated and inflamed. It is strongly suspected that Cherry Eye is due to a weakness of the connective tissue. Cherry eye itself is not heritable but the weakness that allows it to develop may be. If one eye develops cherry eye, then the other eye may also be predisposed. Sometimes the gland can simply be tucked back in but it may prolapse again. The most common treatment is to reposition the gland and surgically tack it into place.

EXCESSIVE TEARING AND STAINING - Also known as Poodle Eye. There are few things more unsightly than rusty tear stains marring the appearance of an otherwise beautifully groomed Havanese. This will of course be most noticeable on white and other light coloured Havanese. Stains are not the only problem, you should take note of tearing and/or eye discharge regardless of the colour of your Havanese. There are a number of reasons for eye discharge and excessive tearing and the unattractive stains that may result. Excessive tearing, blocked tear ducts, acidity or pH of the tears, bacterial or yeast infections, genetics, teething, irritation, allergies, hair in the eyes, environment (smoke & other pollutants) , shampoo and chemicals, diet, food allergy/intolerance are all potential culprits. Camouflaging the stains is a popular option, but in truth, understanding the causes, prevention, and controlling the tear staining are more important than simply covering up.

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hfc