MSD Manual

Please confirm that you are a health care professional

honeypot link

Pharyngeal Lymphoid Hyperplasia (Pharyngitis) in Horses


Bonnie R. Rush

, DVM, MS, DACVIM, Equine Internal Medicine, College of Veterinary Medicine, Kansas State University

Last full review/revision May 2019 | Content last modified Jun 2019

Pharyngeal lymphoid hyperplasia is a condition that occurs in young horses (1 to 3 years old). Unlike humans, horses do not have masses of lymphoid tissue that make up tonsils. Instead, there are follicles of this tissue spread over the pharynx. The follicles blend with normal mucosal tissue as the horse ages, but they are prominent in younger horses. Overgrowth (hyperplasia) may occur. While it was previously thought that the overgrowth was a cause of poor performance in younger horses, it is now thought to be of little significance in most cases. Occasionally these follicles may appear inflamed and produce a discharge that contains mucus or pus; this is likely the result of a mild viral infection, and treatment is usually not needed. Rest and nonsteroidal anti-inflammatory drugs can be used for horses showing signs of pain such as reduced appetite and frequent swallowing.

For More Information

Others also read
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Test your knowledge
Neoplasia of the Eye and Associated Structures
Squamous cell carcinoma is a common neoplasm in several species. Ocular squamous cell carcinoma is most common in animals with light pigmentation around the eyes, because sun exposure is one of several predisposing factors. This tumor is common in each of the following species EXCEPT:
Become a Pro at using our website 

Also of Interest

Become a Pro at using our website