Ultrasound Evaluation of Extracranial Cerebral Circulation (The Common, External and Internal Carotid Artery) in Different Breeds of Dogs

Noninvasive Doppler ultrasonography (US) examination is a standard method for the clinical evaluation of the carotid arteries. Extracranial cerebral circulation includes the common carotid artery (CCA), the external carotid artery (ECA), and the extracranial part of the internal carotid artery (ICA). The present study was conducted with the objective of assessing physiological normative values and describing the appearance of spectral waveforms of extracranial arteries in 104 healthy dogs of eight breeds divided into four groups according to weight. We also focused on searching for correlations for carotid blood velocities with the resistive index (RI), body weight and diameter, and differences between observers and the influence of sex in the calculations of Doppler parameters. In the evaluated breeds, significant differences were found in the velocity of peak systolic velocity (PSV) and end diastolic velocity (EDV). There was a strong correlation between body weight and peak systolic velocity, the RI index and CCA diameter. The intra-observer agreement for the PSV and EDV parameters in each vessel was considered excellent reliability, and overall interobserver agreement showed very good reliability. This study could improve the descriptions of physiological values and waveforms recorded in carotid arteries. Defining the physiological values of velocity and the resistive index (RI) helps in the easier identification of pathology and diagnosis of disease. Our results may be used for further studies of vascular diseases in veterinary medicine that correlate with the pathology of neurological disorders of ischemic origin, further in thromboembolism, oncologic disease and degenerative, proliferative and inflammatory diseases of the arteries that lead to stenosis.

Retrospective analysis of tracheal hypoplasia in brachycephalic and non-brachycephalic dogs: Inter- and intra-observer agreement of measurements

This retrospective study was undertaken on the records of intraluminal diameter of the trachea in 185 dogs, in which hypoplasia of the trachea had been suspected. The relative size of the trachea was measured using the tracheal diameter (TD), thoracic inlet distance (TI), thoracic tracheal diameter (TT) and the width of the third rib (3R), expressed as ratios TD:TI and TT:3R. Thirty-five dogs were diagnosed as having tracheal hypoplasia. Bulldogs and non-bulldog brachycephalic dogs had significantly smaller measured trachea diameters compared to the predicted values calculated on the basis of their body weight. Radiographs of each dog were investigated by four observers. Inter- and intra-observer reliability (ICCinter, ICCintra) was based on the measurements taken by four observers to evaluate the reproducibility of the protocol. There was a good ICCinter (0.8) and ICCintra (0.89) agreement. Craniocaudal tangential radiographs, centred on the cranial thoracic aperture, did not show a significant difference in tracheal diameter measurements compared to the right lateral radiographs. In conclusion, our findings indicate that bulldogs and non-bulldog brachycephalic dogs have smaller tracheal diameters than non-brachycephalic dogs.