Esophagitis and Pharyngitis Associated with Avian Infectious Laryngotracheitis in Backyard Chickens: Two Cases

Abstract

Infectious laryngotracheitis (ILT) is a contagious viral respiratory disease of great economic importance for the global poultry industry caused by Gallid herpesvirus 1 (GaHV-1). Lesions of the upper digestive tract caused by this virus have not been reported before. Two small flocks of backyard chickens experienced an outbreak of ILT, one in 2006 and the other in 2014. These birds had typical ILT lesions, characterized by a necrohemorrhagic laryngitis and tracheitis but were also affected by a severe erosive and necrotic esophagitis and pharyngitis. On microscopic examination of the esophagus and pharynx, numerous individual epithelial cells were degenerated or necrotic. Syncytial cells were present in the mucosa or sloughed in the overlying inflammatory crust, and some of these cells contained an amphophilic intranuclear viral inclusion. GaHV-1 was detected in tissues, from respiratory and digestive tracts, either by PCR, immunohistochemistry, or both diagnostic assays. This case stresses the importance for veterinarians, owners, and technicians to pay attention to different or atypical clinical manifestations of ILT given its highly contagious nature.

Infectious laryngotracheitis: Etiology, epidemiology, pathobiology, and advances in diagnosis and control – a comprehensive review

“…In concurrently infected cases, lesions such as muco-fibrino acute rhinitis and sinusitis, occlusion of paranasal sinuses by caseous exudate, facial swelling, and muco-fibrino tracheitis have been observed (Couto et al 2015). Recently, a solitary case of severe erosive esophagitis and pharyngitis accompanied with epithelial degeneration, necrosis, and syncytia formation with intranuclear inclusion bodies has been reported as an atypical ILT (Sary et al 2017).…”

“…The infected epithelial cells undergo hyperplastic changes followed by lymphocytic and histiocytic infiltrations in the mucosa and submucosa as the disease advances (Russell 1983). Subsequently, the tracheal epithelial cells undergo necrosis with diffuse denudation that results in protrusion and rupture of blood vessels of lamina propria into tracheal lumen leading to severe laryngitis and tracheitis (Sary et al 2017). Intranuclear basophilic or eosinophilic inclusion bodies surrounded by a halo are usually seen during initial stages of infection (1-5 days) and disappear later due to necrosis and denudation of epithelial cells (Seifried 1931;Guy et al 1992;Vanderkop 1993).…”

Genotyping of Infectious Laryngotracheitis Virus (ILTV) Isolates from Western Canadian Provinces of Alberta and British Columbia Based on Partial Open Reading Frame (ORF) a and b

“…ILT is endemic in backyard flocks of Canada [16], and infrequent ILT outbreaks are recorded in commercial poultry operations in many parts of the country [13,[17][18][19], most recently, (2017-2019) an ILT outbreak in the provinces of Ontario and Québec involved commercial chickens [20,21].…”

Disease surveillance in England and Wales, September 2021

“…Histopathology is in progress but the findings were suggestive of ILT; oesophageal lesions have also occasionally been attributed to ILT. 3 These birds also had heavy infestations of red mite (Dermanyssus gallinae); this and other stress factors are likely to trigger clinical disease in birds already carrying the causative gallid herpesvirus type 1 and indicate the importance of controlling parasitic and other diseases as part of good flock management.…”

“…Necrotic foci were also visible in the oropharynx. Histopathology is in progress but the findings were suggestive of ILT; oesophageal lesions have also occasionally been attributed to ILT 3 …”