Eye testing
Everyone knows that genetic testing is important in breeding stock but what about all the pets? At this time, heritable cataracts is a common genetic disorder in the Havanese. This is a somewhat unusual cataract. It cannot be defined as a Juvenile cataract as it may appear as late as 7 years of age. The most common age of diagnosis is 4-6 years of age. Therein lies the problem, as by that time an affected dog may have been bred a number of times and perhaps even to a second and third generation. This is definitely not a senile cataract. In a long lived breed like the Havanese, a senile cataract is unlikely to develop before 9-10 years of age.
These heritable cataracts remain a risk for any Havanese. With such a small gene pool as we have in the Havanese, there are no clear lines. Eye testing remains the best means for us currently to identify this problem. Results of eye tests performed by Certified Veterinary Ophthalmologists can be registered with the Orthopedic FOundation for Animals (OFA). The Canine Eye Registration Foundation was the original eye registry and eye exams are commonly referred to as CERF exams. Unlike many other one-time genetic tests, eye test results are only valid for a period of one year after which time the dog must be re-examined. When purchasing a Havanese, its is wise to choose a breeder who has all their dogs eye-tested yearly and to get a puppy only from two adult dogs who have current clear eye exams. Eye exams are not only for breeding stock and for show dogs. Havanese owners are urged to eye test any and all Havanese on a yearly basis including pets and companion dogs. The earlier any eye problem is diagnosed, the better chance there is of being able to treat it before any eye damage occurs.
So what if one of your dogs fails? The more you know about this problem the better equipped you will be able to deal with it if it happens. Age of onset may matter as dogs afflicted at a younger age (under 3 years of age) seem to have faster more aggressive conditions. Location of the cataracts is also important. While some cataracts do progress rapidly and may lead to blindness, the majority of cataracts in Havanese progress slowly with minimal visual impairment. Surgical intervention may be an option for more severe conditions. The earlier you become aware of any problem the better you can take steps to monitor progression and prevent/treat other associated problems that may develop. The importance of eye testing for all Havanese cannot be over-stressed. Eye-test your Havanese annually or every other year. Every Havanese that is tested adds to the genetic data base and knowledge we have about this hereditary condition and leads us one step closer to finding a solution so we can eliminate it from the breed.
Do take the time to visit the OFA website for additional information on canine eye disorders. You can also look up verification on any dog who has been eye tested and OFA certified as you do your research into breedlines when considering adding a puppy to your family.
Yearly Eye Exams - Why Are They Important?
A common question about eye testing is "Why is certification valid only for one year"? There are myriad eye diseases, some of which can occur at different ages and progress at different rates. An eye examination on a young puppy may diagnose some unchanging eye diseases or may diagnose diseases having potential for getting worse or better or even disappearing with age. Other diseases may not be diagnosed until the dog is a young adult or older. Hereditary cataracts in Havanese rarely develop before 6 months, but may develop as late as 6-7 years. Because vision problems in Havanese don't tend to show up until later in life, it is possible for a Havanese to be clear at 12 weeks and again at 1 year, then not pass the exam at 2 years because cataracts have appeared since the last examination. Having the exam as close to breeding as possible decreases the possibility that a genetic disease has appeared and been missed before breeding again. While yearly examinations cannot guarantee a particular dog is not a carrier or affected of genetic eye disorders, they do show that within the last year, the dog was examined and no genetic eye disease diagnosed at that time. By breeding only eye-clear Havanese, genetic eye disease can be significantly decreased in each generation. It is recommended that all breeding Havanese be eye tested annually till at least 8 years of age. Havanese that are clear at their 9 year old eye exam are unlikely to develop any genetic eye disease after that time. Cataracts after 10 years of age in Havanese are usually considered senile or aging cataracts
The eye registry not only registers Havanese tested and certified free of heritable eye disease but also collects data on all Havanese and all dogs examined by qualified ophthalmologists. The eye registry database is used to research breed susceptibility and trends in eye disease and helps veterinarians, breeders and owners understand more about our breed. After an eye exam, the ophthalmologist sends in a statistical research copy; its information is entered into the database but the individual dog's identity remains confidential. In order to certify your dog, you must mail in the owner's copy of the exam form and pay a small registration fee. Certification is good for 12 months from the date of the exam; after that time the dog must be examined again and re-certified. Getting the eye exam done is the most important part. You don't have to send in your form if you choose not to, though all breeders are encouraged to do so. The advantages of certification are that the dog's exam is recorded in a permanent accessible database. It is easy to check certification on the OFA website which is invaluable for pedigree and breeding research and as a check of health testing.