Ultrasonography to Diagnose Equine Lung Problems
By Stacey Oke, DVM, MSc • Apr 11, 2013 • Article #31676
Ultrasound is a noninvasive tool veterinarians can use to diagnose myriad medical maladies, including those affecting either the lungs or the space around the lungs. Although practitioners perform thoracic ultrasound exams in referral settings routinely, they can also conduct these efficiently and effectively in an ambulatory setting, explained Virginia B. Reef, DVM, of the Department of Clinical Studies at the University of Pennsylvania’s New Bolton Center
During a presentation at the 2012 American Association of Equine Practitioners’ (AAEP) Convention, held Dec. 1-5 in Anaheim, Calif., Reef described the steps involved in conducting a complete ultrasound examination of the lungs and the ultrasonographic appearance of both normal structures and of abnormalities that can affect the equine chest.
“An ultrasound examination of the horse’s chest (thorax) can yield a great deal of information, such as the precise location of the diseased lung, the type of fluid in the chest cavity if it is present, whether the diaphragm separating the abdomen from the thorax is intact or not, and even the area between the two sides of the lung, which houses the heart and important lymph nodes,” said Reef.
Reef described the following abnormalities:
- Pleural effusion: Fluid that accumulates between the lung and the body wall, diaphragm, and heart;
- Pneumothorax: Air that accumulates between the lung and the body wall. Can occur either uni-or bilaterally, and can occur in concert with pleural effusion;
- Atelectasis: A collapsed lung (or portion of) due to fluid or air or to abdominal organs in the case of a diaphragmatic hernia;
- Pulmonary thromboembolism: Debris in the bloodstream lodges in the lung’s small-diameter blood vessels, causing respiratory distress and an elevated heart rate;
- Abscesses involving the lung and/or chest cavity;
- Neoplasia (tumors), granulomas (chronic inflammatory lesions), or fungal disease; and
- Diaphragmatic hernias.
Reef said, “The sonographic pattern of pleural effusions includes anechoic complex nonseptated and complex septated fluid,” referring to how some fluids appear “dark,” either with or without debris floating within them. Reef went on to describe how veterinarians can distinguish between those types of effusions, and how the ultrasonographic appearance of certain types of fluid can help veterinarians determine the fluid’s cause/source.
Reef also reminded veterinarians about the importance of properly preparing the patient for the ultrasound procedure, and briefly touched on patient management.
In conclusion Reef said veterinarians can use ultrasound to help form a more accurate prognosis for survival, select appropriate diagnostics and treatments, and help determine when treatment can be discontinued. Further, ultrasound is a robust and portable tool that allows horses to be examined at home, without a stressful trailer ride to a clinic.