Fifty per cent of all King Charles Cavalier spaniels are affected by an inherited heart murmur.

Experts say breeders should also consider health screening and family history

Breeding dogs on the basis of a single genetic test carries risks and may not improve the health of pedigree lines, warn experts at the University of Edinburgh's Roslin Institute.

The experts say that breeders should use a combination of DNA analysis, health screening and pedigree information to significantly reduce the frequency of inherited diseases.

They add that this approach would also improve genetic diversity, which helps to counteract the risk of disorders.

The recommendations were made following a review of the various approaches that are being carried out to lessen the potential defects in pedigree animals.

Pedigree dogs are created for desirable behavioural and physical characteristics, which often stem from breeding between closed familial lines over many years.

This approach means that inherited diseases can become more common in pedigree populations. For example, approximately fifty per cent of all King Charles Cavalier spaniels are affected by an inherited heart murmur that can be life-threatening.

Dr Lindsay Farrell from The Roslin Institute commented: “Although carrying a specific genetic variant may raise the likelihood that an animal will suffer from the associated disease, it is not guaranteed.

"When making breeding decisions, genetic testing needs to be considered alongside health screening and family history. That will help to keep as much genetic diversity as possible in our pedigree dogs and, at the same time, reduce the prevalence of inherited diseases.”
 
The article is published in the journal Canine Genetics and Epidemiology.

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