RESUMO
Miniature Schnauzers are the first canine breed, in the United States, reported to suffer from primary hyperlipidemia, but this has yet to be documented in other regions. Using over 900 canine plasma samples collected from over seven different veterinary clinics across Japan, the aim of this study was to compare plasma triglyceride (TG) and cholesterol concentrations between Miniature Schnauzers and other purebreeds in Japan. In addition, we investigated the influence of aging and sex on changes to hyperlipidemia incidence in purebred dogs. Our results indicated that both Miniature Schnauzers and Shetland sheepdogs in Japan exhibited remarkably high concentrations of plasma TG and total cholesterol, which are considered to be signs of hyperlipidemia, as compared to other purebred and mixed (Mongrel) canine breeds. Interestingly, the cause and conditions of primary hyperlipidemia in Miniature Schnauzers and Shetland sheepdogs might be different, with hypertriglyceridemia predominantly occurring with Miniature Schnauzers and hypercholesterolemia occurring in Shetland sheepdogs. However, with the influence of aging, the hyperlipidemia evolves into both hypercholesterolemia and hypertriglyceridemia in both groups indicating that the severity of hyperlipidemia positively correlates with aging. Gender differences were also observed with regards to severity. In fact, a higher severity was prevalent with female Miniature Schnauzers than their male counterparts whereas it was more balanced between genders for Shetland sheepdogs.