>We have to test every year in Goldens. It is my understanding that juvenile cataracts >are recessive and a dog can be clear yet still be a carrier. When bred to another >carrier it will then be phenotypically expressed. Juvenile cataracts can show up at a >later age. I have heard numerous tales of dogs that were clear for the first few years >of their life only then to have the cataracts show up at age 4 or 5.
Juvenile cataracts are a major concern in Australian Shepherds. The precise mode of inheritance is not known, but it appears to be recessive and possibly polygenetic. Clear dogs may indeed be carriers. If two carriers are bred together, their offspring can be affected, or be carriers, or be clear, depending on what they inherit from each parent. Age of onset ranges from 3 to 7 years. The term "juvenile" doesn't mean "puppy" but rather "not old-age" in reference to cataracts. Not all cataracts that occur prior to old age are juvenile cataracts, i.e., inherited cataracts -- cataracts can also be caused by trauma, illness, and other factors. In Aussies, a dog that clears until 7 or 8 is considered to be phenotypically free of juvenile cataracts. What is the age of onset of juvenile cataracts in Cavaliers? And Peggy, I believe you said they "used to be called" juvenile cataracts? What are they called now in Cavaliers? Sheila Boneham Perennial Australian Shepherds & One Cavalier! Bloomington, Indiana www.perennialaussies.com ========================================================= "Magic Commands": to stop receiving mail for awhile, click here and send the email: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL to start it up gain click here: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL E-mail [EMAIL PROTECTED] for assistance. Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html All e-mail sent through CKCS-L is Copyright 1999 by its original author.
