Sent in by Peggy McDill
Page 18. addison’s disease in our breed.
To all Standard Poodle owners and breeders:
dna samples are needed for a groundbreaking, well- funded, international study that has already made sig- nificant progress toward finding the genes that cause addison’s disease in Standard Poodles.
While in recent years protocol called for spaying and neutering producers and offspring of addisonians, re- searchers from both the Swedish study and the lark lab say this is not recommended. it is also best, dr. lark says, to breed high risk dogs to very unrelated dogs to improve the chances of breaking up the set of genes that cause the disease.
based in Sweden, this research is a collaboration be- tween dr. Kerstin lindblad-Toh of miT’s broad in- stitute - currently a guest professor at the university of uppsala, Sweden - dr. Åke hedhammar of the Swed- ish university of agricultural Science in uppsala, and dr. anita oberbauer of uC davis.
The scientists from both the Swedish team and the lark lab explicitly advise that breeders proceed on the assumption that this is a polygenic trait.earlier methods of assessing risk are therefore no longer ap- plicable.
Though not yet definitive, these researchers say their dna microarray data thus far suggests a complex trait with multiple loci, or gene regions,indicated for the disease. This is consistent in both Swedish and american Poodles. They believe that the data support a complexly inherited trait and that breeders should use that knowledge when making breeding decisions.
dr. lark says that breeders can do more damage to the gene pool by the wholesale removal of produc- ers or offspring of addisonians from that gene pool than they will by very selectively breeding them. as with any serious polygenic disease, however, it is ex- tremely important to breed with care and with as much knowledge of the lines as possible.
This means that the disease is almost certainly a polygenic trait (controlled by more than one gene) though they do not yet know how the genes interact. it is most likely not an autosomal recessive as previ- ously thought, although it is definitively an inherited disease. environmental contribution to the disease is as yet unknown, but the disease is not random; it is genetic.
additionally, there is ongoing research at the univer- sity of utah’s lark lab on addison’s in Portuguese Water dogs. dr. gordon lark and his colleagues found definitively that multiple genes are involved for addison’s in that breed. They have now been compar- ing the dna of nova Scotia duck Tolling retrievers and, most recently, the dna of Standard Poodles, to that of PWds to see if the suspect gene regions are similar.
dr. Kevin Chase of the lark lab analyzed exhaus- tive health and pedigree data from the Poodle health registry and other private sources. he reportedly found addison’s to be much less frequent in Standard Poodles than earlier studies have shown and far less frequent than in PWds. This means that with care- ful selection, it is possible to reduce the frequency of
dr. Jerold bell writes about polygenic disease in the following article, entitled *managing Polygenic dis- ease*, and he uses hip dysplasia as an example:
_http://www.vin.http://www.vin.http://www.vhttp:// www.vin.htt&Pid=5115&<Wbr>o= ge_ (http://www.vin.com/proceedings/Proceedings.plx?C id=TufTSbg2003&Pid=5115&o=generic)
applying dr bell’s breeding advice to addison’s dis- ease, breeders can follow the same strategy they em- ploy to avoid hip dysplasia and thereby improve their risks:
affected dogs should not be bred.
a dog with close and/or multiple addisonian rela-
tives should not be bred to another with similar risks.
only very high quality dogs with close addisonian
relatives should be bred.
high risk dogs should be bred sparingly and only to
those with very few addisonians in their lines.
Producers and offspring of addisonians should be
replaced with a lower risk offspring or parents of the same quality.
cont. on page 19