Development and application of a focused ultrasound protocol in neonatal foals.

Overview

• This study developed and tested a standardized ultrasound protocol for assessing the thoracic and abdominal areas of neonatal foals to aid in diagnosing health conditions.
• Two protocols were created and evaluated: a detailed Focused Ultrasound (FUS) protocol and a simplified, quicker Foal Oriented Compressed US (FOCUS) protocol designed for emergency situations.

Research Objectives

• Develop a standardized ultrasound protocol using selected thoracic and abdominal acoustic windows for neonatal foals.
• Assess the feasibility and applicability of this protocol in healthy foals.
• Evaluate its utility in detecting common thoracic and abdominal diseases in sick foals.

Protocols Developed

• Focused Ultrasound (FUS) Protocol:
  • Included 12 thoraco-abdominal windows: 4 on the right side, 3 ventral, and 5 on the left side.
  • Performed using a curved-array ultrasound probe.
• Foal Oriented Compressed US (FOCUS) Protocol:
  • A shortened version with 7 thoraco-abdominal windows: 4 right-side, 3 ventral.
  • Designed to be performed from a single right recumbency position to reduce examination time and complexity.

Study Population and Operators

• FUS protocol applied to 17 healthy and 23 sick neonatal foals.
• FOCUS protocol tested on 3 healthy and 3 sick foals.
• Operators included veterinary clinicians with varying levels of ultrasound experience, including those with limited prior experience.

Feasibility and Applicability of FUS

• Good feasibility demonstrated, showing clear visualization of target abdominal and thoracic structures in most cases.
• Applicable for both healthy and sick foals despite the varying clinical conditions.
• Challenges encountered included:
  • Need for changing foal recumbency multiple times during the exam.
  • Large number of ultrasound windows increasing procedure complexity.
  • Requirement for additional staff to restrain the foals safely.
  • Potential conflicts with prioritizing other diagnostic or therapeutic interventions in sick foals.

Diagnostic Usefulness of FUS

• Highly effective in detecting gastrointestinal diseases.
• Accurate identification of peritoneal effusions (fluid in the abdominal cavity).
• Demonstrated value in assessing common thoracic and abdominal pathologies in neonates.

Advantages of FOCUS Protocol

• Significantly reduced examination time compared to FUS—median time of 7 minutes (range 3-10 minutes).
• Performed from a single position, minimizing the need for moving or repositioning the foal.
• Easier to perform in emergency settings where time and resources are limited.
• Successfully conducted by three clinicians with different levels of ultrasound expertise, indicating ease of learning and use.

Limitations Noted in the Study

• FUS protocol requires a single operator to manage image acquisition, which may limit simultaneous management of critically ill foals.
• Small sample size, especially for sick foals assessed with the FOCUS protocol, restricting broad generalization of results.
• Limited evaluation and validation of the FOCUS protocol compared to the more extensively tested FUS protocol.

Conclusions and Clinical Implications

• Focused Ultrasound (FUS) can be effectively performed by veterinarians without extensive ultrasound experience, making it accessible in clinical practice.
• In emergency or time-sensitive situations, the abbreviated FOCUS protocol offers a practical alternative to quickly assess foals with suspected thoracic or abdominal disease.
• Further studies are needed to validate the FOCUS protocol in larger and more diverse populations of sick foals.
• The protocols provide structured tools to enhance imaging diagnostics in neonatal equine medicine and support timely clinical decision-making.