ABSTRACT
Companion animals are affected by multiple vascular diseases. Diseases of lymphatic vessels cause clinical signs that are similar to those induced by vasculitis or phlebitis. Vascular diseases often cause organ dysfunction and tissue injury secondary to loss of blood flow or ischemia. Arterial obstruction results in downstream tissue hypoxia with attendant loss of cell and organ function. Tissue edema is a common pathologic and clinical feature of vascular diseases. Profound hemorrhage can result from traumatic injury or spontaneous rupture of an artery, large vein, or an arteriovenous (A-V) communication, even in the absence of a coagulopathy. Lymphatic vessels also are integral to microcirculatory function. Impaired lymphatic drainage leads to formation of lymphedema or effusions within serous body cavities. Ultrasound imaging, complemented by color and spectral Doppler studies, is especially helpful for identifying abnormal vascular communications and flow patterns. Arteriosclerosis refers to a degenerative or hypertrophic arterial disease that causes vascular wall thickening and luminal narrowing of affected vessels.
