[Encephalopathy and Alzheimer type II astrocytes in a post laparotomy recumbent horse].

The research discusses a case study of a 13-year-old horse that had severe abdominal pain due to a dislocated large colon and other complications, ultimately causing brain dysfunction (encephalopathy) and a distinct type of cellular changes in the brain called Alzheimer type II astrocytes, typically found in cases of liver disorders. However, this unique case did not show any primary liver disease, unlike other similar cases.

Case Presentation

• A 13-year-old Standardbred gelding was examined due to continuous abdominal pain.
• The rectal examination revealed a dislocated large colon, muscle fasciculations, and lethargy.
• The horse was sent to surgery due to persistent colic. On the way, the gelding displayed an unstable walk and a wide-based stance in the hindlimbs just before surgery.
• The laparotomy revealed a retroflexion of the large colon and a secondary mesenterial volvulus.
• Despite the surgical intervention, the horse remained recumbent, immobile, and eventually slipped into a comatose state.

Post-Mortem Examination and Findings

• The horse was euthanized after 15 hours of recumbency due to the comatose state and a dire prognosis.
• The post-mortem examination (necropsy) showed hyperaemic meninges (blood vessel enlargement in the brain’s protective covering causing increased blood flow), edema of gliacells, and submeningeal tissue with vacuolization (formation of vacuoles or cavities in the tissue).
• There was loss of several cerebellar Purkinje cells, essential for motor coordination, and occurrence of Alzheimer type II astrocyte groups within the gray matter of the brain. This type of astrocyte changes are seen in human Alzheimer’s disease and in cases of liver failure, but the horse did not have primary liver disease.
• Other findings included severe hepatolipidosis (fat accumulation in the liver), multiple gastric ulcers, small intestinal hyperaemia with mild mononuclear inflammation, tapeworm infestation of the cecum, and moderate chronic enteritis with eosinophilic component in the large intestine.

Significance of the Case

• This case was unique as it was the first case in a German-speaking country showing the presence of encephalopathy in a horse with colic symptoms but without any primary liver disease.
• The findings highlight the critical need for understanding the potential neurological components and complications in managing horses with persistent abdominal pain and other systemic complications.