[Systematic classification of milk flow obstruction in cattle using endoscopic findings with special consideration of hidden teat injuries].

Evaluation of clinical and endoscopic findings in 224 dairy cows, suffering from milk flow hindrance (MFH), led to a systematic categorization. Dairy cows of different age and race, being patients in the Ambulatorische und Geburtshilfliche Veterinärklinik der Justus-Liebig-Universität, Giessen, and the Tierärztliche Klinik Babenhausen, were used as probands. Just a small amount of animals (8.93%) showed causes for MFH that were inborn or non-traumatic, such as inflammations or foreign bodies. In the majority of cases (91.07%) covered teat lesions (CTL) were diagnosed as causes for MFH. The inner orifice of the papillar duct and the papillar duct itself were found to be the by far most frequent locations of traumatic insult, which was diagnosed as avulsion of the mucosa in 86.16% of cases. Minimal invasive endoscopy proved to be a valuable imaging modality to investigate, document and categorize the diverse alterations of the inner teat cistern lining. Basing on clinical and endoscopic findings, MFH is categorized systematically, paying special attention to CTL as its major cause, and illustrated by comparing endoscopic pictures of typical alterations and physiological findings.