CLINICAL AND ULTRASONOGRAPHICAL EVALUATION OF MAMMARY GLAND DURING MASTITIS IN RUMINANTS

Abstract

Ultrasonography is an effective, non-invasive, non-ionizing and rapid method of detecting pathological changes in the mammary gland in ruminants. The study was designed to evaluate the clinical and ultrasonographical changes in mammary gland during mastitis in ruminants. The mammary glands of 40 lactating crossbred Jamnapari goats and 10 lactating crossbred Holstein Friesian cattle were examined clinically and ultrasonographically using a multi-frequency (5-10 MHz) linear transducer. Somatic cell count was performed on each collected milk sample from each quarter, and classified into three groups as normal, subclinical and clinical mastitis. In goats, 17 animals (42%) had normal, 13 animals (32%) had subclinical mastitis and 10 animals (25%) had clinical mastitis. In cattle, 2 animals (20%) had normal, 3 animals (30%) had subclinical mastitis and 5 animals (50%) had clinical mastitis. On clinical examination of udder in goats, both the subclinical and clinical mastitis were found more frequent in asymmetrical udders compared to symmetrical udders. Pendulous-shaped udders were more affected with both the subclinical and clinical mastitis than spherical-shaped udders. On the other hand, bottle-shaped and cylindrical-shaped teats were more prone to subclinical and clinical mastitis than funnel-shaped teats in goats. During the evaluation of udder and teats, visible abnormalities were observed in clinical mastitis such as swollen udder and teats, induration, pain on palpation, warm on touch and changes in color of the skin etc. Milk abnormalities including white clotted, bloody and watery milk were found in clinical mastitis in both species. The ultrasonographic measurement of teat structures revealed that teat canal length and teat canal diameter were significantly (p<0.05) shorter and narrower in normal animal than both the subclinical and clinical mastitis in goats. Ultrasonographically, clinical mastitis was characterized by a non-homogeneous and hypo to hyperechoic structures of the mammary parenchyma, and gland cisterns were found hypoechoic contents with lack of clear visualization of the lactiferous ducts. Irregularity of contour of the teat wall along with numerous hypo to hyperechoic structures were found in teat cisterns in both the goats and cattle affected with clinical mastitis. In addition, teat cisterns were found anechoic contents as well as somewhat irregularity of teat walls were revealed in normal animals as well as subclinical mastitis. The teat canal obstruction was found in clinical mastitis, where xvi the obstruction was more frequent in teats of cattle than in goats. The ultrasonographic length and width of the supramammary lymph nodes were significantly (p< 0.05) increased in both goats and cattle affected with clinical and subclinical mastitis compared to normal animals. During haematological examination of goats and cattle, hemoglobin, packed cell volume and total erythrocyte count were significantly different (p<0.05) among normal, subclinical and clinically affected animals. Total leukocyte count, the percentage of neutrophils and band cells were significantly (p<0.05) increased in clinical mastitis than the normal and subclinical mastitis in both goats and cattle. As the clinical and ultrasonographical evaluation are the true reflection of mastitis in ruminants, which may assist clinicians in predicting the prognosis of mastitis. Therefore, ultrasonography can be used as a fast complementary technique in field conditions for the proper diagnosis and treatment of mastitis in ruminants.