Don’t forget about ultrasound! Usefulness of ultrasonography in evaluating the equine head and throat regions

Introduction
Ultrasonography is a non-invasive and affordable imaging modality used in equine practice. Its complementarity to radiography is widely demonstrated.

Objective
This presentation aims to illustrate the clinical application of ultrasonography in the imaging investigation of the equine head and throat through a retrospective review of clinical cases.

Material and Methods
Medical records of 46 horses having undergone head and/or throat ultrasonography were retrospectively reviewed. Horses having undergone ocular ultrasonography and horses affected by strangles were excluded.

Results
In all horses, ultrasonography was used as a complement to radiography. Nineteen horses underwent ultrasonography to explore suspected bone and/or soft tissue infections. In these cases, ultrasonography was useful to confirm or demonstrate bone involvement, the presence of a bone sequestrum and/or areas of bone lysis. In preoperative assessment it also aimed to assess the morphology of fistulous tracts and/or abscesses. Power Doppler was useful to support the hypothesis of infection. Thirteen horses were examined for suspected neoplasia. In these cases, ultrasonography was used to assess tumor extent and vascularization, presence and extent of bone lysis and lymph nodes involvement, as well as to guide fine needle aspirations. In the remaining cases, ultrasonography was used to investigate miscellaneous conditions including focal swellings, lymph nodes, temporo-mandibular joints and laryngeal morphology.

Discussion and conclusion
This retrospective review indicates the usefulness of ultrasonography as an adjunct to radiographic examination to complete the initial imaging investigation of the equine head and throat regions. Because of its low-invasiveness and wide availability, its use for head and throat investigation should be promoted in equine practice.