A study of residual lesions in horses that recovered from clinical signs of chronic equine dysautonomia

• Published in: Journal of veterinary internal medicine 2019-09, Vol.33 (5), p.2302-2311
• Main Authors: Milne, Elspeth M., Pirie, R. Scott, Hahn, Caroline N., del‐Pozo, Jorge, Drummond, Dawn, Moss, Sharon, McGorum, Bruce C.
• Format: Article
• Language: English
• Subjects: Amyloid beta-Protein Precursor - analysis; Amyloid precursor protein; Animals; Autonomic nervous system; BAPP; Biomarkers; Case-Control Studies; Colon; c‐kit; Depletion; Disease Progression; Dysautonomia; Dysphagia; Enteric nervous system; Enteric Nervous System - pathology; EQUID; Ethics; Euthanasia; Ganglia; grass sickness; horse; Horse Diseases - pathology; Horses; Hospitals; Hypertrophy; Ileum; Interstitial cells; Interstitial Cells of Cajal; intestinal motility; Intestine; Intestines - cytology; Intestines - innervation; Lesions; Motility; Mucosa; Muscles; Myenteric plexus; Nervous system; Neural networks; Neurodegeneration; Neurons - pathology; Pathology; PGP 9.5; Primary Dysautonomias - pathology; Primary Dysautonomias - veterinary; Prospective Studies; Proteins; Proteins - analysis; Proto-Oncogene Proteins c-kit - analysis; Small intestine; Spinal cord; Staining; Submucosal plexus; Ubiquitin; Ubiquitin - analysis
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/jvim.15567

Background Equine dysautonomia (ED) causes degeneration and loss of autonomic neurons. Approximately 50% of chronic cases recover, but it is unclear how they survive neuronal loss. Objectives To assess lesions, autonomic neuron numbers, interstitial cells of Cajal (ICC), and neurodegeneration in recovered cases. Animals Thirteen cases (group ED), euthanized 10.3 ± 5.2 (1–16) years from diagnosis and 6 age‐matched controls (group C). Methods Prospective, case control; routine post mortem examination, neuron counts in peripheral and enteric ganglia and immunohistochemical assessment of neural networks (Protein gene product [PGP] 9.5), ICC (c‐kit), and neurodegeneration (beta‐amyloid precursor protein and ubiquitin) in intestine. Results Postmortem findings in group ED were small intestinal dilation (4/12, 33%) and muscular hypertrophy (4/12, 33%), and gastric mucosal hypertrophy (3/11, 27%) and ulceration (4/11, 36%). Neuron density was lower in group ED (mean 39% lower for cranial cervical ganglion [P