Ultrasound evaluation of mammary gland cistern in quarters affected by mastitis: new diagnostic grading

Mastitis, the inflammation of the mammary gland, represents one of the main pathologies in dairy cattle farm. It leads to se-vere economic losses and drug administration, representing a relevant problem for animals, farmers, and public health. Diag-nosis mainly consists in analysis on milk, such as microbial culture, PCR and somatic cell count. Considering the vitally importanceof a fast and reliable diagnosis, the aim of this research is to evaluate ultrasound mammary examination as an on-farm tool ableto timely detect and characterize quarters affected by mastitis. For this purpose, 39 primiparous and multiparous dairy cattle froma single farm in Veneto Region (Italy) have been enrolled. For each animal, clinical examination, ultrasound examination of themammary gland and milk sampling of single quarter have been performed. Animals have been divided into four groups basedon symptoms, microbial culture and somatic cell count. Specifically, CTR” (control, having no clinical signs, negative microbialculture and SCC< 200.000 cells/ml), “IMI” (Intramammary infection, having no clinical signs, positive microbial culture andSCC <200.000 cells/ml), “SUB” (subclinical, having no clinical signs, positive microbial culture and SCC ≥200.000 cells/ml) and“CL” (clinical, having clinical signs, positive microbial culture and SCC ≥200.000 cells/ml). An ultrasound classification of theechogenicity of the content of the mammary gland cistern has been proposed from 0 (completely anechoic cistern), to 3 (com-pletely echogenic cistern). Considering the non-homogenous distribution of data, Kruskal-Wallis rank sum test has been applied.Results show significant differences between groups of SCC (means ± standard deviation 18.39±3.21, 33.75±5.12, 608.71±148.50,1267.20±94.98 from group 0 to 3 respectively) and ultrasound score (means ± standard deviation 0.71±0.2, 0.84±0.11, 1.00±0.38,2.60±0.24 from group CTR to CL respectively. Moreover, SCC values were significantly different also considering US Score (means± standard deviation 32.52±7.25, 91.92±39.11, 109.08±57.78, 412.07±159.52 from score 0 to 3 respectively). Even though fur-ther studies are needed in order to validate and deepen this technique, these results suggest a possible application of ultrasoundexamination as a fast and immediate detection instrument of mastitis.