Radiographic appearance of the thorax of clinically normal alpaca crias

Utilizing smartphone-based electrocardiography and thoracic radiography to evaluate cardiac function and morphology in geriatric Sika deer (Cervus nippon)

OBJECTIVE

To describe qualitative and quantitative cardiothoracic values in geriatric Sika deer (Cervus nippon) using digital radiography, 6-lead ECG (sECG), and smartphone-based ECG (aECG).

ANIMALS

10 healthy geriatric Sika deer (9 females and 1 male).

PROCEDURES

Deer were chemically immobilized, thoracic radiographs were obtained, and inhalant anesthesia was initiated. An sECG and aECG were simultaneously recorded for each animal using the same ECG specifications. Results were compared between devices.

RESULTS

Radiographically, no deer had any cardiopulmonary abnormalities. Median (range) values for the most important cardiac measurements were 170 (153-193) mm for cardiac height, 135 (122-146) mm for cardiac width, 9 (8-9) for vertebral heart score, and 99 (69-124) mm for cardiosternal contact. All deer had a normal sinus rhythm with no pathological arrhythmias noted. A significant difference between sECG and aECG was identified for minimum heart rate (49 vs 51 beats/min, respectively), P wave duration (0.05 vs 0.03 seconds), P wave amplitude (0.28 vs 0.10 mV), PR interval (0.15 vs 0.12 seconds), and QT interval (0.39 vs 0.30 seconds).

CLINICAL RELEVANCE

Thoracic radiographs were suitable to evaluate basic cardiothoracic morphology in Sika deer. The aECG was useful for assessing heart rate and rhythm but, compared with sECG, proved no substitute for evaluating duration and amplitude of ECG waveforms.

Ventricular septal defect and double-chambered right ventricle in an alpaca

A 20-month-old male alpaca was referred for evaluation of a cardiac murmur evident since birth. Echocardiography identified a ventricular septal defect (VSD) and a fibro-muscular band causing a stenosis of the right ventricular outflow tract. Right ventricular catheterization and selective angiography confirmed the diagnosis of VSD and double-chambered right ventricle with bidirectional shunting.

Computed tomographic characterization of the pulmonary system in clinically normal alpacas

OBJECTIVE

To characterize and quantitatively assess the typical pulmonary anatomy of healthy adult alpacas with multidetector row CT.

ANIMALS

10 clinically normal adult female alpacas.

PROCEDURES

CT examination of the thorax was performed before and after IV administration of iodinated contrast medium in sedated alpacas in sternal recumbency. Measurements of the trachea, bronchi and related blood vessels, and selected vertebrae as well as the extent and density of lung parenchyma were performed with a Digital Imaging and Communications in Medicine (DICOM) viewer. Morphometric and quantitative data were summarized.

RESULTS

Separation of individual lung lobes could not be identified, except for the accessory lung lobe. In all alpacas, both lungs extended farther caudally at the medial aspect than at the lateral aspect. The right lung extended farther in both cranial and caudal directions than did the left lung. The branching pattern of the bronchial tree varied only slightly among alpacas and consisted of 1 cranial bronchus and 3 caudal bronchi bilaterally, with a right accessory bronchus. Luminal diameters of first-generation bronchi ranged from 3 to 9 mm. Mean ± SD parenchymal lung density was -869 ± 40 Hounsfield units (HU) before contrast injection and -825 ± 51 HU after contrast injection. Mean difference in diameter between bronchi and associated arteries or veins was 0.8 ± 0.9 mm.

CONCLUSIONS AND CLINICAL RELEVANCE

Knowledge of the typical anatomy of the lungs and bronchial tree in healthy alpacas as determined via CT will aid veterinarians in clinical assessment and bronchoscopic evaluation of alpacas.