Equine Internal Medicine Q&A 06

This question was provided by Manson Publishing as part of the OVAL Project. See more Equine Internal Medicine questions

You examine a four-month-old foal with bilateral swelling behind the ramus of the mandible. In the past few weeks a number of the young horses on this large farm have had bilateral purulent nasal discharge, fever and submandibular lymphadenopathy. Only this foal has the large swelling just caudal to the ramus of the mandible.

Question	Answer		Article
What is the likely diagnosis?	Guttural pouch empyema.		Link to Article
What is the aetiology of this condition?	Guttural pouch empyema is frequently seen following infection by Streptococcus equi subspecies equi. While many horses with strangles develop guttural pouch empyema, the condition is often self-limiting and rarely results in severe distension of the guttural pouches.		Link to Article
How would you treat this foal?	Guttural pouch empyema may respond to daily irrigation with physiological saline solutions. The purpose of topical infusions is to dislodge and remove debris from the guttural pouch. Infusions should be repeated once or twice daily until the infection has resolved. Topical antibiotics are rarely effective in guttural pouch empyema because they are unable to penetrate tissues or kill organisms within the brief contact time achieved, and many are inactivated by the products of inflammation. Systemic treatment of guttural pouch empyema is rarely indicated unless there is evidence that the infection is spreading and involving other tissues. If the response to irrigation is poor or if the purulent material becomes inspissated, surgical drainage of the guttural pouch should be considered. An hyovertebrotomy incision combined with ventral drainage through Viborg’s triangle or a modified Whitehouse incision are the approaches of choice.		Link to Article