Are mongrels healthier than pedigrees?

In the latest October issue we say in Jemima Harrison's article on whether you can prove mongrels are really healthier than pedigrees we would publish the references on this blog - so here they are:-

• B.N. Bonnett, A. Egenvall, P. Olson, A. Hedhammar, Mortality in Swedish dogs: rates and causes of death in various breeds, The Veterinary Record, 1997. ("Mongrels were consistently in the low-risk category.")

• P.D. McGreevy & W.F. Nicholas, Some Practical Solutions to Welfare Problems in Pedigree Dog Breeding, Animal Welfare, 1999. ("Hybrids have a far lower chance of exhibiting the disorders that are common with the parental breeds. Their genetic health will be substantially higher.")

• A. Egenvall, B.N. Bonnett, P. Olson, A. Hedhammar, Gender, age, breed and distribution of morbidity and mortality in insured dogs in Sweden during 1995 and 1996, The Veterinary Record, 2000. ("Mongrel dogs are less prone to many diseases then the average purebred dog.")

• A. R. Michell, Longevity of British breeds of dog and its relationship with sex, size, cardiovascular variables and disease, Veterinary Record, 1999. ("There was a significant correlation between body weight and longevity. Crossbreeds lived longer than average but several pure breeds lived longer than cross breeds, notably Jack Russell, miniature poodles and whippets”.)

• G.J. Patronek, D.J. Walters, L.T. Glickman, Comparative Longevity of Pet Dogs and Humans: Implications for Gerontology Research, Journal of Gerontology, Biological Sciences, 1997. ("The median age at death was 8.5 years for all mixed breed dogs and 6.7 years for all pure breed dogs. For each weight group, the age at death of pure breed dogs was significantly less than for mixed breed dogs.")

• H.F. Proschofsky et al, Mortality of purebred and mixed breed dogs in Denmark, Preventive Veterinary Medicine, 2003. (Higher average longevity of mixed breed dogs. Age at death when split into three age bands: mixed breeds 8,11,13, purebreds 6, 10, 12.)

• Marta Vascellar et al, Animal tumour registry of two provinces in northern Italy: incidence of spontaneous tumours in dogs and cats. BMC Veterinary Research 2009. (“In both dogs and cats, purebreds had an almost two-fold higher incidence of malignant tumours than mixed breeds.”)

• Agneta Egenvall et al, Mortality in over 350,000 Insured Swedish Dogs from 1995–2000; Breed-Specific Age and Survival Patterns and Relative Risk for Causes of Death. Acta Veterinaria Scandinavica, 2005. (No difference overall, but mongrels low-risk for locomotor problems and heart disease.)