Ехографски проучвания на физиологични и патологични състояния на млечната жлеза при козата
Ultrasonography studies of caprine mammary gland physiology and pathology
кози; млечни жлези; ехографска диагностика
The main goal of the present research was to investigate the potential of ultrasonography for detection and diagnosis of changes occurring in some physiological and pathological states of mammary gland in goats. A total of 232 goats were investigated between 2009 and 2013. The experimental animals were 2- to 8-years old, weighing 40 to 62 kg. Goats were between their 1st and 7th lactation, and studies were conducted between the 1st and 8th lactation months. The comparison of our goat ultrasonography data to those reported by other authors in different species (cows, sheep, buffaloes) showed some common traits based on the similar udder anatomy in ruminants. The analysis of results showed that the “water bath” technique was better for investigation of the teat, whereas the transcutaneous method – for investigation of the other udder structures. Our goat udder ultrasound data obtained using different approaches demonstrated that the “direct contact” and “standoff” techniques could be successfully used for visualisation of proximal teat structures (teat cistern and the transition between teat and glandular cisterns) in the goat. A high-quality ultrasound image could be attained through high-frequency (10.0 MHz) linear probe. All teat structures in the goat could be observed by means of the “water bath” technique using a linear probe with frequency of 5.0 MHz or higher. Ultrasonography is a rapid and accurate method for determination of dimensions of caprine udder structures. The data obtained during the different stages of lactation showed a clear tendency towards reduction of teat canal length, teat canal diameter, the diameter in the region of the Furstenberg’s rosette and the largest teat cistern diameter. The ultrasound imaging allows for detection of stenoses and obstructions in all parts of the teat (proximal, middle and distal) in goats. In acute mammary gland inflammations, ultrasonography could be used for diagnostics of occurring changes and for evaluation of the extent of udder lesions. In goats with acute Staphylococcus aureus mastitis, ultrasound mammary gland changes are clearly depicted. Significantly less deviations could be observed in animals with streptococcal mastitis. The ultrasound image of the mammary gland in goats affected by staphylococcal mastitis is characterised by heterogeneous and hyperechoic structure of the parenchyma, blurred visualisation of the mammary canals and blood vessels, thickened and hyperechoic teat wall, and multiple hyperechoic structures in the teat cisterns (milk coagula). The analysis of data demonstrates that caprine mammary gland ultrasonography could be used as a diagnostic imaging method for detection of deep local pathological processes such as abscesses. In cases of udder indurations, ultrasonography could detect the extent of parenchymal lesions and the presence of areas with normal hypoechoic structure, if present. In experimental Staphylococcus aureus mastitis in goats, leukocyte counts, blood fibrinogen and haptoglobin were statistically significantly increased by the 8th hour of infection. The most evident ultrasound changes were observed 72 hours after the intracisternal inoculation of the pathogen. Depending on the changes in tissue echogenicity, the possibility for visualisation and udder structure measurements, ultrasonography could determine the extent of udder damage and to monitor the effect of therapy.