Animal ID: 2 months old, female, Merino lamb.
Organ: Liver and brain samples fixed in formalin collected during the the necropsy.
Clinical findings: In the clinical examination, it was observed that the animal tilted its head to the side while standing, turned to the direction in which its head was tilted when it moved, and fell down, and the presence of incoordination. Sudden convulsion and ataxic seizures were observed in the lateral position. Grinding of teeth was also seen.
Macroscopic findings: In the external examination of the brain, the meninges had an opaque appearance. Fibrinopurulent exudate was seen in the brain gyrus (Fig. 1). Numerous Coenurus cysts with a diameter of approximately 0.5 cm were scattered throughout the brain (Fig. 2). Disseminated inflammatory foci with a diameter of approximately 1 mm were observed in the liver (Fig. 3).
Cytological Findings: The presence of a small number of bacteria, together with dense neutrophil leukocytes and eosinophils was noted in impression smears made from the meninges (Figure 4).
Histopathological Findings: In the meningeal and submeningeal areas, vascular hyperemias with severe neutrophil and to a lesser extent mononuclear cell infiltrations were observed (Fig. 5). In the microscopic appearance of Coenurus cysts, which were scattered in the brain; foci of parasites surrounded by a cyst capsule were observed (Fig. 6). Foreign body giant cells, neutrophils, eosinophils, and mononuclear cell infiltrations were noted around the parasitic foci (Fig. 7). Presence of necrotic tunnels suggesting local parasite migration and severe inflammation around these areas were observed (Fig. 8). Disseminated parenchymal and perivascular inflammatory cells were also observed in the areas other than those affected by parasites (Fig. 9). Occasionally, status spongiosis was seen in the white matter (Fig. 10). Severe mononuclear cell infiltrations were noted in the portal areas of the liver.
Microbiological analysis: Escherichia coli were isolated in the bacterial culture from brain and liver samples. Antibiogram test revealed sensitivity only for the Ceftiofur.
Diagnosis: Acute coenurosis, purulent meningoencephalitis, Escherichia coli septicemia
Differential diagnosis: Listeriosis, brain abscesses, tumors, otitis, louping ill, oestrus ovis, intoxication, copper deficiency, cerebrocortical necrosis, hydatidosis.
References:
Miller AD and Zachary JF. Nervous System In: James F. Zachary; Editor, Pathologic Basis of Veterinary Disease, 6th Edition, Elsevier Inc. 2017. pp.845-846.
Cantile C and Youssef S. Nervous System. In: M.Grant Maxie, Editor, Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals, 6th Edition, vol.1, Elsevier Inc. 2016, pp.389.
ASKJPC, JPC #2026219, https://www.askjpc.org/vspo/show_page.php?id=YjNYMHp6ZHAvRTlNbkI2d3Njd09QZz09
Archive Material: Burdur Mehmet Akif Ersoy University, Faculty of Veterinary Medicine, Department of Pathology, Burdur, Türkiye
Block ID: 225/22
Owner: Ali Cenk Kocabıyık, Yarıköy, Burdur, Türkiye.
Figure legends:
Macroscopy:
Figure 1. Macroscopic view of brain tissue, purulent exudate accumulation (arrows).
Figure 2. Circular cavitations (arrows) formed by the cystic area in the cerebral cortex.
Figure 3. Disseminated foci in the liver.
Cytopathology:
Figure 4: Neutrophil and eosinophil leukocytes (arrow) in impression smears made from meninges. Hemacolor. Bar: 20 µm.
Histopathology:
Figure 5. Thickening of the meningeal vessels with hyperemia and severe inflammatory cell infiltrates (arrows). H&E, Bar: 200 µm.
Figure 6. Parasitic cyst area, cyst capsule (arrows) and peripheral inflammatory infiltrates. H&E, Bar: 200 µm.
Figure 7. Mononuclear cell infiltrates, foreign body giant cells (arrows), necrotic debris and neutrophil infiltrates around the cystic area. H&E, Bar: 50 µm.
Figure 8. Severe neutrophilic infiltrates, necrotic debris, and dense mononuclear inflammatory cell infiltrates around the necrosis area (arrows). H&E, Bar: 200 µm.
Figure 9. Perivascularly located neutrophil, eosinophil (arrows) and lymphocyte infiltrates. H&E, Bar: 20 µm.
Figure 10. Scattered parenchymal and perivascular inflammatory infiltrates in the area of severe status spongiosis (arrows). H&E, Bar: 200 µm.