Evaluation of Atherosclerosis Development by Vascular Duplex Ultrasonography in ApoE-deficient Dogs Fed with a High-fat Diet

Objective This study aimed to evaluate the development of atherosclerosis in ApoE-deficient dogs fed with a high-fat diet (HFD) using vascular duplex ultrasonography (VDU). Methods Thirty beagle dogs were enrolled, including 10 wild-type, 16 heterozygous (ApoE-/+), and four homozygous (ApoE-/-) mutant dogs. The dogs were categorized into either the normal diet (ND) or HFD group. Plasma lipids levles were tested at baseline and then after feeding the dog a different diet for 6 months. The carotid arteries, abdominal aorta (AO) and iliac arteries were examined using VDU. Artery sections of the ApoE-/- dogs were analyzed. Results After HFD, lipids especially triglycerides, total cholesterol and low-density lipoprotein (LDL) in the wild type and ApoE-/+ dogs were significantly increased. Both the intima-media thickness (IMT) of the common carotid artery (CCA) and AO in the wild type and ApoE-/+ dogs significantly increased. In the ApoE-/+ dogs, the mean percentages increases in CCA-IMT and AO-IMT after HFD were higher than those in the ND dogs. The mean values of CCA-IMT and AO-IMT in the ApoE-/-dogs increased to 2-2.5 folds after HFD. Histological analysis confirmed that the carotid and iliac arteries had advanced atherosclerotic lesions in the ApoE-/- dogs. Conclusions HFD may accelerate the development of atherosclerosis in ApoE-deficient dogs, which is an optimal large-animal model of atherosclerosis.