           −  B-MODE ULTRASONOGRAPHY OF MAMMARY GLANDS IN GOATS DURING THE LACTATION PERIOD I. R. FASULKOV, P. I. GEORGIEV, A. L. ANTONOV & A. S. ATANASOV Department of Obstetrics, Reproduction and Reproductive Disorders, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria  Fasulkov, I. R., P. I. Georgiev, A. L. Antonov & A. S. Atanasov, 2010. B-mode ultra- sonography of mammary glands in goats during the lactation period    , , No 4, 245−251. The goal of the present study was to establish the ultrasonographic features of the mammary gland in goats during lactation. Twenty-four animals of a local breed within the first to fifth month of lactation, bred at the clinical facilities of the Faculty of Veterinary Medicine and private farms in the Yambol and Stara Zagora districts, were included in the study. During the B-mode ultrasonography of the different mammary structures, the 5 MHz ultrasound probe was placed in horizontal and vertical position related to the examined subject. Two methods of examination were used – direct (transcutaneous ultrasonography) and immersion of the examined organ in water (“water bath” method). The mammary papilla was best scanned in vertical position, whereas the mammary parenchyma – in horizontal probe position. The application of the “water bath” method was more effective when examining the mammary papilla, and the transcutaneous method – when examining the structures in the other areas of the mammary gland. There were differences in the visualizations of the separate structures of the udder, depending on the presence or not of the offspring. It is thus recommended to perform ultrasonography of lactating goat’s mammary gland at least 2 hours after the last milking or separation of the offspring from goats.  : goats, mammary gland, ultrasonography INTRODUCTION Mammary gland health is essential for goats’ productivity (Smith & Roguinsky, 1977; Bergonier  , 2003; Contreras  , 2007). Production of high-quality milk and dairy products bears high social significance in Bulgaria and is closely related to the udder’s condition (Zunev, 2003). Also, the preservation of the mammary gland’s physiological function is an important premise for the breeding of healthy and vital offspring. Ultrasonography is a non-invasive imaging technique, applied in the diag- nostics of various physiological and pathological conditions of reproductive organs in animals (Carrière  , 2002; Dimitrov  , 2002; Georgiev  , 2003; Kähn, 2004; Yotov  , 2008). B-mode, also known as real-time ultrasonography, is most widely used as the dynamics of the processes is shown in real time on the screen as a two- dimensional greyscale image (Dimitrov  , 2004; DesCôteaux  , 2010). The intensity of the reflected sound depends on the acoustic resistance (acoustic