Final answer:
The most likely diagnosis for a 7-year-old ewe presenting with abscessation of the supramammary lymph nodes is Corynebacterium pseudotuberculosis, which causes Caseous lymphadenitis in small ruminants like sheep and goats. CLA is a highly contagious disease that can lead to economic losses, but it can be prevented and controlled with strict biosecurity measures, management, and vaccination.
Step-by-step explanation:
The most likely diagnosis for a 7-year-old ewe presenting with abscessation of the supramammary lymph nodes is Corynebacterium pseudotuberculosis. This bacterium is the causative agent of a condition called Caseous lymphadenitis (CLA), which affects small ruminants like sheep and goats.
CLA is characterized by the formation of abscesses in lymph nodes, particularly in the mammary glands. The abscesses contain a thick, cheesy material, hence the name Caseous lymphadenitis.
CLA is a highly contagious disease, and it can lead to significant economic losses in livestock production. Strict biosecurity measures, proper management, and vaccination are key strategies to prevent and control the spread of CLA.