I think what Laura is trying to say, albeit a bit dramatically, is that if we narrow the population of studs used to the few typey heart-clear over 5 dogs in the CKCSCUSA that don't produce epilepsy, poor temperament, etc, is that we will begin to have greater homozygosity in our breed. The price for that homozygosity of genes is often a blow to the immune system. (with which I think cavaliers already have problems, to some degree) While our immune system problems at the moment are confined to conditions such as thrombocytopenia, rough coat, pyometra, thyroiditis, etc, we are fairly fortuntate in that we don't have a lot of cancers at young ages, like some of the other breeds. We need to be careful not to use this as an excuse to breed poor hearts, hips, etc, but at the same time watchful that we don't end up with a new disease or more frequent debilitating condition due to the "popular sire syndrome". For those interested in reading about the popular sire syndrome, just go to google.com and search for that term -- it will bring up several hits for dogs and horses. Related abstracts below.
Leanne ---- Vet Q 1992 Dec;14(4):137-40 The relationship between homozygosity and the occurrence of specific diseases in Bouvier Belge des Flandres dogs in The Netherlands. Ubbink GJ, Knol BW, Bouw J.Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands. Since purebred dog populations represent closed gene pools, a relatively high level of consanguinity between individuals, and hence of inbreeding, is common. This case control study was conducted to establish the possible connection between the actual level of homozygosity due to inbreeding and specific diseases (flea allergy, osteochondrosis, laryngeal paralysis, neoplasm, autoimmune disease, hypoplastic trachea, and food allergy) occurring in the Bouvier Belge des Flandres breed. One hundred and sixty-eight animals referred to the Utrecht University Clinic formed the patient group. Each of the seven diseases was chosen because of the demonstrability of the diagnosis. Each animal was chosen because one of the selected diseases was established in that individual, and because its pedigree was complete. All dogs of the patient group were born between 1 January 1980 and 31 December 1985. A control group (n = 123) was randomly chosen from the total population of registered Bouviers born in the Netherlands in the same period. pedigree data were obtained from the Dutch Kennel Club. The extent of inbreeding was determined for all animals using Wright's inbreeding coefficient. The distribution of inbreeding coefficients in each patient group was compared with the distribution in controls. Inbreeding coefficients in the control group ranged from 0.0 to 0.406. Animals in which osteochondrosis, food allergy, autoimmune disease, neoplasm, or hypoplastic trachea was diagnosed had higher inbreeding coefficients than controls. It was concluded that in the Bouvier Belge des Flandres dog population examined, the level of homozygosity was positively correlated with occurrence of these diseases. ------- J Natl Cancer Inst 1976 Sep;57(3):545-8 Inbreeding and canine mammary cancer: a retrospective study. Dorn CR, Schneider R. Using files of the Animal Neoplasm Registry (ANR) in Alameda and Contra Costa Counties, California, we conducted a retrospective study to compare the degree of inbreeding in the ancestry of purebred dogs with mammary and other cancers, and of those without tumors. Wright's coefficients of inbreeding, calculated for all animals in the three groups, ranged from 0.000 to 0.535. The median inbreeding coefficients of the mammary cancer and comparison groups (consisting of other cancers) were approximately twice that of the nonneoplastic group. ----- Leukemia. 1997 Apr;11 Suppl 3:187-8. Possible relationships between canine hematopoietic neoplasia, other malignancies and immune mediated diseases.Theilen G. School of Veterinary Medicine, University of California, Davis This report gives relationships between canine hematopoietic, other neoplasia and immune mediated diseases in two families of inbred dogs that possibly were also infected with a yet to be fully described retrovirus. ========================================================= "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 2002 by its original author.
