AA amyloid-associated gastroenteropathy in a horse.

The research article is about a case study of a horse suffering from Systemic Amyloidosis, a rare disease that affected its digestive system, causing dramatic weight loss, excessive saliva, anemia, and malabsorption of nutrients.

Background

• Systemic Amyloidosis is a rare disorder where misfolded proteins, known as Amyloid, deposits in various organs in the body, impairing their function. This particular study is about a case of systemic amyloidosis involving the digestive tract in an 11-year-old Morgan stallion horse.

Clinical Symptoms and Signs

• The horse experienced several clinical signs like weight loss, excessive salivation (ptyalism), anaemia, high count of neutrophils, low albumin protein levels and elevated level of gamma globulins (hypergammaglobulinaemia). These signs demonstrated a sick animal with balance disturbance in blood components which affected its normal bodily functions.
• The D-xylose absorption test further indicated malabsorption problem in the horse. D-xylose is a type of sugar; if it is not absorbed properly, it indicates issues with the digestion and absorption of nutrients in the gut.

Post-mortem Investigation

• Detailed necropsy was performed which revealed damages to various parts of the digestive system like oral, oesophageal and gastric ulcers, and reddened segments of small bowel mucosa with slight to moderate bleeding. Amyloid deposits were identified in all parts of the digestive system except the outer covering known as the serosa.
• Amyloid was also detected in other organs as well, like the spleen, lymph nodes, liver, kidneys, lungs, pancreas and bone marrow, indicating a systemic spread of the disease.
• The deposits were found to be most prominent in the small bowel mucosa and arteries within the Submucosa, which is a fatty thick layer beneath the inner lining of the small intestine.
• All of these deposits reacted typically to AA amyloid with a specific staining procedure, further confirming the diagnosis of Amyloidosis. The type of amyloid was found to be ‘AA’, was identified to be the same as found in canine and bovine using peroxidase-antiperoxidase technique which is a immunohistochemical method.

Conclusion

• Even though the cause of the amyloidosis in this case could not be pinpointed, the hematological and serological data suggested that an underlying chronic inflammatory process could be at play. This chronic systemic inflammation can trigger the mechanisms to produce and deposit the amyloid proteins.