Day Blindness Update                         

Author Heather Bryan
http://standardpartipoodle.com

As many of you know, in the summer of 2007, we had a litter of Standard Poodles of which two females, about six weeks of age, began showing signs of vision difficulty in bright light. Our initial diagnosis was confirmed in October when Dr. Kristina Narfstrom of the University of Missouri Columbia flew to Phoenix to perform ERG’s (Electroretinagram) on the affected puppies, as well as two unaffected Poodles, which allowed her to confirm the diagnosis. Nearly six months later, Dr. Narfstrom returned to Phoenix to perform follow-up ERG‘s and document any changes. Unfortunately, there was noted deterioration in the vision of both affected puppies.

Both affected puppies have remained here in the Phoenix area and have wonderful homes! They are doing so well that, although they are now nearly blind, they don‘t let that stop them! They both live with great families who adore them. Hopefully, sometime in 2009, Dr Narfstrom will return to Phoenix for another follow-up ERG.

This past summer, I was contacted by a breeder who had a litter of Standard Poodles that had several puppies who showed signs of being day blind. At the time, she had no idea of the cause and was advised to euthanize the affected puppies, which she did. It was only after she read the articles posted about Day Blindness in Standard Poodles that she realized there was likely a connection. Notably, she indicated that the pedigree of her litter had quite a few common ancestors whom we now believe to be the strong link as a probable source of the disease.

This past February, I was contacted by a couple who had purchased a Standard Poodle puppy six weeks earlier. They had noticed he had odd behavior when he was outside in bright sunlight. After consulting their veterinarian and doing hours of research online, the woman came across an article I had written about my experiences with day blindness in Standard Poodles. The symptoms described were eerily similar to her dog’s, so she contacted me for any information that I might be able to provide. Immediately, I gave her Dr Narfstrom’s contact information, and advised her to contact an eye specialist so that they could get a medical diagnosis of her puppy.

Since the initial contact was made with me, the puppy has been returned to the breeder. On April 10th, 2009, Dr. Narfstrom flew out to the office of the breeder’s veterinarian and performed ERG’s on the three remaining puppies in the litter. Of the puppies tested, two were confirmed to have inherited Hemeralopia from their parents.

There was a notable vision difference between the two puppies in this litter and my own litter. My girls showed more advanced vision loss at the time of their initial ERG, while the puppies from this litter had more visual capabilities. I wrote to Dr. Narfstrom about this, and here is a bit of her response to the issue:

“As I explained earlier I found that two of the three puppies that were examined with ERGs were affected by cone rod dystrophy causing mainly day blindness at this point in time. It appears that it is the same kind of disease I see in these puppies as the disease we saw in Heather's dogs. The main difference is that the disease in Heather's dogs was more advanced, even at the first time of examination (done when the dogs were four-six months old).

“This is not an uncommon finding when it comes to cone rod problems. In the Dachshund, for example, with the cord1 mutation, there is a great heterogeneity that has been described for the disease. This means that some dogs get it very early on and go blind early while some get it later in life and don't seem to lose vision completely. But all of this needs to be studied in the Standard Poodle more thoroughly, and I hope to go back to do follow-up ERGs in about four months.

“I suspect that the gene defect (the mutation) is the same in both (litters). Therefore we should continue to work with finding more affected dogs so that blood can be collected, as well as pedigrees, in order to find the specific mutation and provide a test for this disorder.”

On a side note, I should let you know that this current litter of puppies was raised in a state that has severe winters, and that the litter spent no time outside prior to going to new homes in January. I feel as though this may have played a part -- or at least have been a contributing factor – in the degree of actual vision loss to date. The girls from my litter, on the other hand, have spent their lives in very sunny Arizona.

The breeder of the litter with the Day Blind puppies wrote this note to me after I had completed the article: Last night, when I finally had some time to think about the above statement in your article,
it isn't necessarily true. Gustafe spent approximately 2 months in sunny Florida where he was outside most of the daylight hours according to the schedule his owners sent home with him. His testing showed much better reception than the little girl who spent her time indoors. Gustafes' rods were normal, the cones were bad.

Pedigrees of the grandparents to the new Day Blind puppies;
Dam: DHP's Mocha Latte Sweetheart # PP66459902
Sire: Hooligan, My Heart's Desire #PP63087001

Dam: Kit-Sue's Skylar HighDollar #PP660784/01
Sire: Smith's Tuxedo Jacque #PR032756/03

Not long after I was contacted by the puppy owner with the affected puppy, I spoke with Dr. Narfstrom about the on-going research. One of the most fascinating things I left the conversation with is that, with the technology the University of Missouri Columbia has available today, they will probably be able to find the DNA marker for this disease with blood work from as few as six to ten confirmed affected Standard Poodles. They now have blood work from four affected dogs, as well as at least a dozen closely related Poodles. They could possibly have a DNA marker within the next two years.

The Genetics Research lab at the University of Missouri Columbia is always in need of blood samples from dogs who may have a strong relation to the known affected Poodles. To view the pedigree’s of the parents of my litter, I’ve posted the following links.

http://www.poodlepedigree.com/pedigree.asp?ID=332323
http://www.poodlepedigree.com/pedigree.asp?ID=333864

If you have a Standard Poodle who has common ancestors in the above pedigrees, we strongly encourage you to donate blood samples to the University of Missouri’s Genetics Research Lab. The following link is the form that should be filled out when submitting the blood samples.

Note: There is no fee involved in donating blood as this is a research project. When filling out the form CROSS OUT “Test Being Requested” and write “Requested blood sample for Standard Poodle Dayblind Research.”

http://www.caninegeneticdiseases.net/DNAtests/TESTSnow.htm

You can also contact the office directly for more information. Liz Hansen is extremely helpful with information. Her email address is:

hansenl@missouri.edu and the office phone # is (573) 884-3712

The International Parti Poodle Club is also working on ongoing fundraising for the University of Missouri Columbia’s research of this disease. For more information please visit:

http://dayblind.org/