Ultrasonographic findings of mammary glandof goats naturally infected with caprine arthritis encephalitis virus

ABSTRACT

The caprine arthritis encephalitis is a virosis with worldwide distribution in livestock and in the mammary form chronic mastitis is prevalent, which can cause assimetric and hardening of the udder, known as indurative chronic mastitis leading to reduction in milk production. The ultrasound is a good method of assessing the mammary gland, because the technique is non-invasive, fast, and easy to apply. This study aimed to evaluate the ultrasonographic features (grayscale, echogenicity, and homogeneity) of mammary parenchyma of 20 seroreacting goats and 20 not seroreacting for caprine arthritis encephalitis virus. It was observed that the average diameter of retromammary lymph nodes of seroreacting animals (0.72cm) to caprine arthritis encephalitis virus was smaller (P= 0.02) than in non seroreacting animals (0.93cm). In analysis between the portions of the udder, the grayscale values of the distal third of the caudal portion of the mammary parenchyma was higher in seroreacting animals (P<0.0001, right side; P= 0.02, left side). Such data suggest that the increase in ultrasonographic grayscale of mammary parenchyma of goats can be correlated to chronic changes caused by caprine arthritis encephalitis, as indurative mastitis. In relation to the subjective aspects of echogenicity and homogeneity, the groups showed no difference between them (P>0.05), displaying mostly heterogeneous and hypoechoic standards. From the results, this study points to evidence that the caprine arthritis encephalitis can cause changes in grayscale measurable by ultrasound, and this can be used as an efficient and non-invasive helper method for monitoring and early detection of indurative mastitis.

Keywords:
caprine; image; retrovirosis; mammary gland; chronic disease