The dog fancy has taken a similar approach to dealing with their flawed product. Two years ago, UC Davis published a study finding some genetic diseases common to all dogs apparently occur at the same rates in mutts and purebreds. AKC apologists rapidly seized on this finding, even though it didn't actually say what they thought it did. In fact, for 10 of the 27 diseases surveyed, purebred dogs had notably higher incidence rates than mutts. Yesterday, I encountered a similar study (original at PLOS One) with even brighter news for the KC (or so they would have you believe). Originating from a survey of English veterinary records and paid for by the RSPCA, the press release version claims "purebreds are no more likely than crossbreeds to suffer the most common disorders", i.e. the diseases they studied had equal incidence in both purebreds and mutts, based on reviews of veterinary practice data throughout that country. In fact,
- For three of the most common 20 diseases (otitis externa [ear infections], obesity, and skin masses), the incidence in purebreds was materially higher (p<0.05) than in "crossbred" dogs (in fact, dogs of unknown provenance).
- Four of the 20 "mid-level" diseases (musculoskeletal issues, aural, opthamological, and again obesity, though not sure why that latter is counted in this group again) again have materially higher incidences in purebreds than mutts; none were higher in mutts than the general population.
- For specific breeds, some problems were more frequent and some were less than the general population. This is to be expected.