The word cataract, while simple in definition, is wide ranging in terms of significance. Whenever there is a breakdown of the lens fibers in the lens capsule, the condition is referred to as a cataract. The causes can be varied, some considered hereditary, some a result of trauma, disease, drugs, diet, or the normal process of aging. One of the problems with the way cataracts are reported by CERF (Canine Eye Registry Foundation) is that there is little differentiation between the various causes since they are simply reported as cataracts and the dog fails CERF, or it is reported as “significance unknown”. If the ophthalmologist doing the examination considers the eye condition as not genetic in nature then it may be reported in the “breeder option” category of the CERF public on-line database.
A blow to the eye that results in a temporary cataract that may eventually heal is reported on the OFA (Orthopedic Foundation for Animals) public database and CERF in the same way as a small punctate cataract, that may or may not grow into a mature cataract. At this time, punctates are not considered progenitors to cataracts in the Havanese according to the ophthalmologist that I use for my dogs. The only way to determine if the cataract labeled as “punctate cataract, significance unknown” is of any importance in terms of breeding is to ask the dog’s owner to see the comment section of the CERF sheet.
In searching for a way to breed away from eye disease the breeder is forced, once again, to proceed looking for a solution based mostly on data from the rumor mill. While the stud’s owner may be one hundred percent honest about the dogs under her care, what about the dogs behind her dogs. Where can we get one hundred percent accurate information on past generations? We cannot.
We all know that only a dog that passes CERF has the results shown on-line unless extra forms are signed, and immense effort is taken to have the dog’s negative results displayed. If a dog shows as no longer being recorded there is no way of knowing why. The dog may have died, been taken out of a breeding program for some benign reason, changed owners, or an infinite number of other reasons. The only way to find out for sure is by asking the individual dog’s owner. This is a rather time consuming, and in reality an impossible task when looking at an entire pedigree. So what do we do if we find a dog out of our own breeding program has produced a cataract and we need to take steps to try to breed to a line fairly clear of this? According to the CERF statistics report for 2007, over twenty percent of our Havanese had various forms of eye disease that caused them to fail CERF. The 2008 statistics are not available as yet but hopefully we will see a drop in this percentage.
Why do we put so much importance on submitting CERFs when we receive so little information from the database for our individual breeding programs? I assume it is in the hopes of having a researcher somewhere at some time discover the pattern or genetic nature of eye disease in Havanese. This goal is extremely worthwhile, but possibly years away from a solution for our breed. We don’t even have an established pattern of inheritance according to an email communication that the author had with the Animal Health Trust in England. Part of the reason for this may be due to the presence of multiple genes causing cataracts that behave differently. As an example, scientists at the Animal Health Trust have successfully identified the mutation that causes both hereditary cataract (HC) in Staffordshire Bull Terriers and French Bulldogs and early onset hereditary cataract (EHC) in Boston Terriers. They do not know the cause of cataracts that occur in the three or four year old Bull Terriers. As well, we may have something like that found in the Australian Shepherd where there is a particular mutation that indicates a risk factor for the development of cataracts. Dogs that carry this particular gene are 12 times more likely to develop cataracts in both eyes than those that don’t. The mutation is dominant, which means that dogs need only inherit a single copy of it, from either parent, to be at risk. If the dog has two copies of this gene, the risk factor increases.
Whatever the genetic cause, isn’t it time we as breeders and protectors of our Havanese decide to take matters into our own hands? Rather than sit back and wait for some researcher, somewhere, to discover the gene that causes cataracts in our breed why can’t we take a pro-active stand and do what is within our power to do? We could create our own database showing the CERF results for all our Havanese. Yes, it is important to continue to send the results into CERF as well, but “just imagine” what we could do if we had a complete database in existence right now.
Maybe it is time to come out from under the conspiracy of silence and ignore the convention that helped perpetuate the problem. There is no shame in producing a health issue of any kind; we are dealing with complicated biological systems, not mechanical widgets. The only shame is not taking steps to rid our Havanese of any health issue. Taking large numbers of dogs out of the gene pool has proven not to be the answer either. In fact, I suspect that if we removed every Havanese that was thought to be a possible carrier for cataracts we would have next to no dogs left. There are many hard working honest breeders who have taken drastic steps to avoid disease, but they need the help of all the breeders not just a few. The most logical solution has to be for all the breeders to work together.
In the article “Responsible Breeding Management of Genetic Disease” by Jerold Bell DVM, Department of Clinical Sciences, Tufts Cummings School of Veterinary Medicine, he states, “It is important that as breeders and veterinarians we encourage open reporting of health results. The days of stigmatizing conscientious, health-testing breeders who have produced dogs with hereditary disease are gone. No one wants to produce affected offspring from their matings, and no one should be blamed if this occurs (unless the breeder is not doing the recommended health testing). It should be everyone’s goal to produce healthy offspring, but this is not possible if the only available health information is about healthy dogs.”
I have heard several people say that they are breeding to European dogs because it is compulsory in certain countries in Europe for all breeders to report their health testing. Something is wrong with this picture. If it works for other countries, then why aren’t we doing it here in North American? We need an independent Havanese Eye Database, sanctioned by the Havanese clubs. If such existed, we could probably reduce the number of cataracts and eye problems significantly in just a few short years. Isn’t it time to keep the competition inside the ring and out of the medical arena? The solution to healthier Havanese is so simple. It is being done in other breeds such as the Scottish Terriers where long-time, experienced breeders know the value of cooperation for the sake of their beloved animals. We can do this; it is simply a matter of “Will we?”
Addendum:
The statistics from the 2008 CERF results are just in. In the year 2007, there were 2,231 dogs which were examined by a canine ophthalmologist. In the year 2008 there were 2,227. The percentage of affected dogs actually increased by several percentage points but what is also disturbing is that despite the increase in the number of Havanese being bred, there are actually fewer Havanese being CERFed. This could be explained in part, but not totally, by the switch by some breeders to another breed name, but that’s not the whole story. We seem to have a need to get our message about health testing and particularly eye exams to a much larger audience of new breeders.