Megaesophagus in Friesian horses associated with muscular hypertrophy of the caudal esophagus.
Friesian horses have a perceived high rate of congenital or hereditary diseases, including megaesophagus, that may lead to choke and death. A retrospective study was performed to determine the prevalence and pathologic characteristics of esophageal disease in 852 horses, including 17 Friesians, that had been necropsied over a 6-year period at the Diagnostic Center for Population and Animal Health. Forty-two horses had grossly described esophageal lesions (25 muscular hypertrophy, 7 hemorrhage, 6 megaesophagus, 4 erosion/ulceration, 3 obstruction, 2 tears, 2 secondary neoplasms, 2 lymphoid patches, 1 thin wall, 1 esophagitis). Some of these lesions occurred concurrently in the same horse. Ten of these horses died or were euthanatized because of severe esophageal disease (6 megaesophagus causing tears in 2 horses, 3 esophageal obstruction with food bolus, and 1 esophagitis). All 6 horses with megaesophagus were Friesians. No cause for megaesophagus was noted in the necropsy reports; however, 5 of these 6 Friesians had marked caudal esophageal muscular hypertrophy (wall thickness: 1.9 ± 0.3 cm). Microscopic review of the esophagus of these Friesians confirmed smooth muscle hypertrophy, with no obvious fibrosis, degeneration, or loss of myenteric plexi. Unlike the Friesians, the 4 non-Friesian horses with severe esophageal disease had esophageal obstruction with an intraluminal food bolus or severe esophagitis. None had caudal esophageal muscular hypertrophy. It is concluded that in comparison to other horse breeds, Friesians have a higher prevalence of severe esophageal disease, specifically megaesophagus, that is commonly associated with marked caudal muscular hypertrophy.
Diagnostic Center for Population and Animal Health (DCPAH) and Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan.
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Komine
Diagnostic Center for Population and Animal Health (DCPAH) and Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana langohr@msu.edu.
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Langohr
Diagnostic Center for Population and Animal Health (DCPAH) and Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan.
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Kiupel
D000818:Animals; D001947:Breeding; D004931:Esophageal Achalasia / Q000473:pathology / Q000662:veterinary*; D004947:Esophagus / Q000473:pathology*; D005260:Female; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses; D006984:Hypertrophy / Q000662:veterinary; D008297:Male; D009130:Muscle, Smooth / Q000473:pathology; D015995:Prevalence; D012189:Retrospective Studies; D013045:Species Specificity
Friesian horse; esophagus; horse; megaesophagus; muscular hypertrophy; pathology; retrospective study; smooth muscle