Ultrasonographic imaging of the tongue and larynx in normal dogs

ULTRASONOGRAPHY OF THE EQUINE LARYNX

Nasopharyngeal and laryngeal evaluation is important when examining horses with upper airway signs for poor performance. Currently endoscopy is the most common method to evaluate the equine upper airway. Ultrasonography of the equine larynx has not previously been described. Using six cadaveric specimens and four standing horses, the ultrasonographic appearance of the equine larynx was established. A scanning technique, including useful acoustic windows and the normal ultrasonographic appearance at each site, is described. Ultrasound allowed visualization of portions of the hyoid apparatus, laryngeal cartilages, associated soft tissues, and intrinsic and extrinsic laryngeal musculature, that are not seen using endoscopy. Additionally, real-time ultrasound allowed observation of the movement of the vocal folds and the arytenoid cartilages during respiration. In three horses with arytenoid chondritis, ultrasonography aided in the diagnosis and localization of arytenoid abcessation and perilaryngeal inflammation. The establishment of this technique will serve as the basis for future investigations in the evaluation of clinical patients with upper airway abnormalities.

Echolaryngography in cats

Twenty-five cats with clinical signs of upper respiratory tract disease and five cats without upper respiratory signs underwent echolaryngography. Direct inspection of the larynx under general anesthesia was undertaken in all cats and used as the 'gold standard' for the diagnosis of laryngeal diseases. The aims were to: (a) establish which anatomic structures of the larynx are visible ultrasonographically in cats without upper respiratory tract disease, (b) establish which laryngeal abnormalities can be detected and accurately localised using ultrasonography and (c) evaluate in which conditions the technique may provide complementary information or an alternative method of investigation. The ultrasound investigation accurately indicated the presence and location of cysts and masses. Abnormal laryngeal movements were also detected, although it was difficult to confirm whether these were unilateral or bilateral. Vocal cord thickening was seen but the underlying cause could not be established with this technique.

The role of ultrasound in the assessment of laryngeal paralysis in the dog

Forty dogs with clinical signs suggestive of upper respiratory tract disease underwent echolaryngography and laryngoscopy. Laryngoscopy was used as the definitive technique to diagnose laryngeal paralysis. The ultrasound investigation accurately indicated the presence of the paralysis and confirmed the uni- or bilateral nature of the disorder. Findings indicative of laryngeal paralysis included asymmetry or absence of motion of the cuneiform processes (30/30), abnormal arytenoid movement (16/30), paradoxical movement (9/30), caudal displacement of the larynx (2/30) and laryngeal collapse (1/30). Thirty dogs were found to be afflicted with laryngeal paralysis and ten had normal laryngeal motility.

Ultrasonographic imaging of the vagosympathetic trunk in the dog

The purpose of this study was to evaluate the applicability of ultrasonographic imaging of the vagosympathetic trunk in the dog. Cervical ultrasound was performed in 30 healthy dogs. In all 30 dogs the vagosympathetic trunk was detected as a hypoechoic structure in the carotid sheath, adhering the dorsomedial surface of the common carotid artery. The echotexture of the nerve was heterogeneous with anechoic areas separated by hypoechoic bands. A scanner equipped with a 5 to 8 MHz linear array probe was used for imaging and measurements. The diameter of the vagosympathetic trunk ranged from 0.59 to 2.48 mm varying in correlation to the body weight. In summary, ultrasonography is a helpful noninvasive method to image and evaluate the cervical vagosympathetic trunk in the dog.

Everted laryngeal saccules: ultrasonographic findings in a young Lakeland terrier

The ultrasonographic appearance of laryngeal eversion due to bilateral laryngeal paralysis is described in a young Lakeland terrier.

Ultrasonographic diagnosis of a laryngeal cyst in a cat

The ultrasonographic appearance, surgical treatment and pathological classification of a laryngeal cyst in a four-year-old cat is described. This is the first description of such a cyst diagnosed with the help of ultrasonography. The cat presented with dyspnoea and respiratory noise. An intraluminal fluid-filled cyst attached to the vocal cord was identified by ultrasonography and drained under ultrasound guidance. The cyst recurred three weeks later and ultrasonography showed an increase in size compared to the previous examination. There was no evidence of recurrence of the lesion 18 months after surgical removal.

Ultrasonography of laryngeal masses in six cats and one dog

Ultrasonography of laryngeal abnormalities in small animals allows the identification of laryngeal masses because of the resulting distortion of normal structural/anatomical relationships. It also allows fine-needle aspirates to be taken with minimal risk of causing hemorrhage or edema affecting the already narrowed laryngeal lumen. Findings in six cats and one dog with laryngeal abnormalities are described.