A 9-year-old Nubian wether goat was presented for neurologic decline. The owner found the patient down in the field. Upon examination the goat was noted to have a head tilt and opisthotonus, and was still recumbent. Over the following days he continued to decline, so the owners elected euthanasia and submission to the Frederick Animal Health Laboratory. On necropsy, the distal ileum was thickened with a rugose mucosa. The antimesenteric border had multifocal to coalescing pinkish white flat to round foci to nodules with an umbilicated to necrotic center through the entire intestine. The ileocecocolic lymph node was markedly enlarged with multiple small white foci and necrotic tissue. In the thorax, a large mediastinal mass extended cranially from the thoracic inlet up the right side of the neck, compressing the trachea and larynx. There were numerous white fibrous adhesions in between the mass and the parietal pleura. On cut surface, the mass had many small white, gritty foci and multiple necrotic regions. The primary differentials on gross necropsy were two separate diseases, thymoma and Johne's disease (Mycobacterium avium ss. paratuberculosis). The histopathologic exam of the intestinal wall thickening and enlarged mesenteric lymph nodes showed irregular borders infiltrating adipose and connective tissue with medium sized lymphocytes with scant cytoplasm, small, round, heterochromic nuclei and small nuclei as well. A high number of mitotic figures were seen. The same neoplastic lymphocytic cells were seen in the mediastinal mass, mesenteric lymph nodes, and intestinal wall. The goat was diagnosed with multicentric lymphosarcoma with vascular invasion on histopathology.