Laryngeal contact ulcers in feedlot cattle

Area of Science:

• Veterinary Pathology
• Bovine Medicine
• Animal Science

Background:

• Contact ulcers are observed in the bovine larynx, specifically on the vocal processes and medial angles of the arytenoid cartilages.
• Previous observations indicate a higher incidence of these lesions during the fall feeding season.

Purpose of the Study:

• To investigate the prevalence and potential causes of contact ulcers in the larynges of feedlot cattle.
• To explore the hypothesis that infectious mucositis, combined with laryngeal closure mechanisms, contributes to ulcer formation.

Main Methods:

• Examination of 30,444 larynges from fattened cattle across three companies.
• Statistical analysis of lesion incidence based on feeding season.

Main Results:

• A total of 3,985 larynges (13.1%) exhibited contact ulcers or ulcer scars.
• The incidence of contact ulcers was significantly higher in cattle fed during the fall season compared to other seasons.

Conclusions:

• Feedlot cattle may develop acute mucositis due to mixed infections (Pasteurella, Haemophilus, Mycoplasma, viruses).
• Reflex coughing and swallowing may accelerate larynx closure, leading to erosion of the laryngeal mucosa over the vocal processes.
• This process is hypothesized to be the primary mechanism for the development of contact ulcers in the bovine larynx.