Actually, the reason they use Malinois is because they have a greater prey drive, and therefore are easier to train to attack. They are not as reliable as German Shepherds when working around people, and most of the ones used by the services are bred especially. The 'show bred' ones are less feisty. If you notice at the police dog championships they showed, there are very few Malinois who take part.
From Wikipedia:
"The average lifespan of the Belgian Malinois is 10-12 years,[6] and there are a number of health problems and disorders that are associated with the breed, though the breed's health is generally considered better than that of the German Shepherd Dog. Notable health problems prevalent to the Malionois includes cataracts,[7] epilepsy,[8][7] thyroid problems, progressive retinal atrophy (PRA), hip dysplasia,[6][7] and pannus, although these problems have been minimized through selective breeding."
Threecats, hip displasia is not life threatening, so whether or not they had been hip scored this would not have caused their early demise.