Health and Genetics Report, September 2003
MaryDee Sist, DVM
I feel very fortunate to have attended the AKC Canine Health Foundation Canine Health Conference Sept. 19-21, 2003 in St. Louis Missouri. The focus of the conference was caring for the health of your breed. Seminars ranged from cardiology, cancer and genetic testing updates to presentations on behavior and training, to alternative therapies. Due to the evaluations from last year's conference participants, there were more scientific presentations and less 'plugs' for Purina (who kindly sponsored the meeting) and the AKC, which made this an excellent and informative meeting. I also appreciated the opportunity to discuss various health issues with representatives from other breeds as well as the researchers.
Another member of the health committee, Linda Deutsch, attended the conference. Caroline Coile also attended as a press representative for Dog World Magazine. I am sure Caroline will write an excellent synopsis of the conference and publish it in the magazine or on a Saluki list. I will put a summary of the presentations on SHR's website. The conference proceedings will be available on the IVIS website (ivis@wanadoo.fr) as are the proceedings of the CHF 3rd Cancer Conference (IVIS Newsletter No. 5), which I attended a few weeks ago. Therefore, this report will address presented information that needs further discussion and input from SCOA members.
PURINA PARENT CLUB PARTNERSHIP PROGRAM (PPCP)
In this program, money is given to the sponsoring parent club for each qualifying feed bag weight circle that a Pro Club enrolled breeder sends in to Purina. 50% of the money from Purina goes into the breeds Donor Advisory Fund and 50% goes to the clubs treasury to help fund health or education programs. Purina's goal in establishing this program is to positively impact the general well-being of the breed.
Initially Purina required the parent club to furnish an address list of all club members. To qualify for the weight circle program, a member must have at least 5 dogs AND breed no less than three litters per year. I felt these requirements were excessive and excluded most SCOA members. However, Purina has become more lenient and no longer requests a membership list. Each owner now has to breed ONE litter per year to qualify for enrollment. Since Purina has modified the requirements more than 60 Parent Clubs have enrolled and it has been a good source of income for some.
Is the SCOA interested in promoting membership and participation in the Purina Pro Club? It would be a source of income for the SCOA. It would be up to each individual owner to make the choice to feed Purina and sign up for the program.
CANINE HEALTH INFORMATION CENTER (CHIC)
CHIC was established as a centralized canine health database jointly sponsored by the AKC/CHF and OFA to collect health information on individual dogs. The goal is to assist breeders in making more informed breeding decisions and for scientists conducting research. Because each breed has different health concerns, the parent club has input as to what screening tests for inherited diseases are required. With permanent identification of the dog a CHIC number and CHIC report are issued listing the tests and dates they were performed. This does not imply normal test results and the owner has to approve making the results publicly available. Quarterly reports consisting of both aggregate numbers and specific dogs that have been issued CHIC numbers are provided to each participating club. Currently 26 breeds are participating.
The concept of a health registry for each breed is certainly beneficial to the health of our dogs. While each parent club can customize the required testing, it currently incorporates OFA and CERF data bases. Should we consider enrolling Salukis who have OFA heart, thyroid, hip and elbow dysplasia and CERF certification? When the inherited nature of the diseases prevalent in our breed, like cancer and various heart conditions, is known and screening tests become available, then I think this would be an excellent program to participate in.
ESTABLISHING VERTICAL PEDIGREES
Of most interest to me in caring for the health of our breed, was information OFA made available, written by Rhonda Hovan, Collecting and utilizing phenotypic data to minimize disease: A breeder's practical guide, which was reprinted from the OFA website, www.offa.org
In summary, the article showed that vertical pedigrees can be much more informative when assessing health concerns than standard horizontal pedigrees which include only direct ancestors such as parents and grandparents. Each dog carries genes from its family and while parents and grandparents (horizontal) are certainly influential, the total health of the siblings, and Aunts and Uncles, etc. (vertical) are more influential. The principal is that full siblings are, on average, equally genetically similar to each other as they are to each of their parents. All of the littermates taken as a group represent various combinations of their parents' genes, and are good indicators of the RANGE OF POSSIBILITIES that are likely to be passed on from any one of them. Thus, dogs that do not even appear on traditional horizontal pedigrees, may be more significant genetically than are the more distant relatives that do.
Whenever multiple genes and/or other complex modes of inheritance are involved, a larger sampling will be more likely to contain enough individuals to indicate a pattern. She used the example of hip dysplasia and the selection of a sire who has fair hips versus one with good hips, both having parents certified free of hip dysplasia. It would seem that to reduce the incidence of hip dypslasia that a sire with better hips should be selected. But, when a vertical pedigree was complied, the dog with fair hips had normal siblings, while the dog with good hips had 3 dysplastic littermates. Compiling vertical pedigrees through the grandparents showed that the dog with fair hips had a genetic package favoring normal hips. But the dog with good hips was from a family with a high incidence of hip dysplasia and thus the dog would be more likely to transmit dysplasia.
She goes on to say that it is important to consider the frequency of the disease in the vertical pedigree as compared to the frequency of the disease in the breed populations and the location of the affected individuals on the pedigree.
Since even respectable and desirable pedigrees often contain an occasional affected dog, a realistic goal for breeders is to use those pedigrees which demonstrate a significantly lower rate of the disease as compared to the general population.
DNA tests, which offer genotypic information, are not available for the majority of common canine diseases. Most tests intended to offer breeders health information about a dog's suitability for breeding rely instead on an evaluation of the dog's physical status at the time of examination or are phenotypic tests such as OFA or CERF evaluations. Many harmful genes do not manifest as detectable diseases during the prime breeding age of the dog. Until science has evolved to allow carrier testing for pertinent health issues in our breed it behooves all of us to establish a vertical pedigree and use it in our breeding decisions to insure improved health for our special breed.