A 27-mo-old, spayed female mixed-breed dog was presented with left forelimb pain, which progressed to full thickness necrosis of the soft tissues of multiple limbs. Clinical imaging and postmortem examination suggested multiple large arterial thromboemboli. Histologic examination of vascular lesions revealed markedly thickened tunica intima with polypoid intraluminal projections, which partially to entirely occluded the arterial lumen. The expanded tunica intima was comprised of intimal accumulation of Alcian blue–positive matrix with scattered spindle-to-satellite cells. These cells were positive for von Willebrand factor and vimentin but negative for α–smooth muscle actin, suggesting endothelial origin. Deposition of the intimal mucoid matrix was observed in the elastic and muscular arteries associated with regional ischemic changes. Mucoid emboli, likely from fragmentation of proliferative intimal tissue, were identified in smaller vessels supplied by affected arteries. Based on these findings, we diagnosed systemic mucoid degeneration of the arterial tunica intima. Such systemic arterial degeneration characterized by deposition of mucoid matrix in the tunica intima has not been reported previously in dogs, to our knowledge, and should be distinguished from thromboembolism and other degenerative vascular diseases.

一只 27 个月大的绝育雌性混种犬出现左前肢疼痛，并进展为多条肢体软组织全层坏死。临床影像学和尸检提示多发大动脉血栓栓塞。血管病变的组织学检查显示内膜显着增厚，腔内有息肉状突起，部分或完全阻塞动脉管腔。扩张的内膜由内膜积聚的阿尔新蓝阳性基质和散在的梭形到卫星细胞组成。这些细胞对血管性血友病因子和波形蛋白呈阳性，但对 α-平滑肌肌动蛋白呈阴性，表明内皮起源。在与局部缺血变化相关的弹性和肌肉动脉中观察到内膜粘液基质的沉积。在受影响动脉供应的较小血管中发现了可能来自增殖性内膜组织碎裂的粘液栓子。基于这些发现，我们诊断出动脉内膜系统性粘液样变性。据我们所知，这种以内膜中粘液样基质沉积为特征的全身性动脉变性以前在狗中没有报道过，应与血栓栓塞和其他退行性血管疾病区分开来。