As owners and breeders of pedigree dogs, we have a responsibility towards the health and welfare of our hounds. There is no room for complacency in the current climate if we wish to retain the privilege of being able to breed selectively. We need to demonstrate our abilities regarding this or risk having regulation imposed upon us.
All pedigree dogs are genetically predisposed to disease as a consequence of restricted gene pools. It is vital to monitor disease as well as ensuring that the gene pool is as diverse as possible. Health initiatives can involve clinically based surveillance schemes such as ultrasound scanning for cardiac disease. More recently DNA based testing looking for particular abnormal, or mutant, genes has become available and is certain to be of increasing usefulness and importance.
The body make up is determined by genes that are contained on chromosomes within the cells of the body, half of which come from one parent, and half from the other. Some traits are determined by many genes working together whilst others by only one gene.
Factor VII deficiency (FVIID) in the deerhound is determined by one gene only. Each dog has 2 copies of this gene, one from each parent. A dog affected by FVIID will have 2 abnormal copies of the relevant gene. A carrier of FVIID will have one abnormal and one normal copy but cannot be FVII deficient because the normal gene is dominant. A carrier however can pass the abnormal gene to its offspring. The diagram below demonstrates the inheritance of FVIID.
Whilst widespread bleeding problems are not being seen in our deerhounds, it would be prudent that this is monitored by identifying the genotypes of our breeding stock.
Information on the status of an individual hound could be relevant in the case of injury or surgery when bleeding could be expected. Animal Diagnostics is now able to test DNA from cheek swabs to determine the genetic status with regards to FVIID and as the amount of testing increases so will the knowledge pool regarding FVIID and other canine disease. Their web site is here
For more information about FVIID please refer to the very informative article
“Inherited Factor VII Deficiency in the Deerhound” written by Sue Finnett and Hector Heathcote, which was published in the Summer 2006 Newsletter. Other relevant articles and correspondence appear in the Winter & Spring editions.2006/7
It is stressed that the object of DNA testing for FVIID is NOT to exclude hounds from the breeding population but rather to allow informed choice. Indeed with a breed like ours, that has a relatively small gene pool, it would be a great mistake to restrict breeding to hounds that test normal for FVIID.