Ultrasound evaluation of common carotid artery blood flow in the Labrador retriever

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.

Long-lasting canine cardiovascular alterations following bromocriptine induced-estrus

Bromocriptine (BRM), a dopamine 2 receptor agonist, is a common drug for inducing estrus in dogs. It is also used for the treatment of some endocrine abnormalities and has some cardiovascular consequences in the patients under treatment. The current study aimed to evaluate its effects on the cardiovascular function of dogs during administration and the subsequent induced estrus cycle. Eight non-pregnant female dogs were assigned into control and treatment groups. The control group (n = 3) were dogs that showed proestrus naturally. The treatment group (n = 5) received oral incremental (μg/kg) doses (100 on days 1 and 2, 200 on days 3, 4, and 400 on days 5 until the proestrus expression) of BRM tablets (2.5 mg; Iran-Hormone Co, Iran). The left ventricle function, carotid blood flow indices, and systolic (SAP) and diastolic (DAP) arterial pressure were recorded every two days. The phases of the cycle were determined using a vaginal smear. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI) had a sharp decline following the administration of BRM (P < 0.05). The carotid PSA, EDV, RI, and pulse index were lower during induced estrus compared to the control (p < 0.05). BRM-induced estrus showed a different pattern of changes compared to the normal cycle from day 9 (p < 0.05) onwards. The cardiovascular effects of BRM remained for days after the termination of administration which may interfere with reproductive functions.

Effect of supra-nutritional selenium-enriched probiotics on hematobiochemical, hormonal, and Doppler hemodynamic changes in male goats

In this study, the influence of supra-nutritional organic selenium (Se) supplement on hematology and plasma biochemicals, including antioxidant parameters and plasma reproductive hormones, as well as blood flow characteristics in the supratesticular and common carotid arteries (STA and CCA, respectively) were investigated. For this purpose, 15 male goats were used and classified into three equal groups according to the supplementation of the basal diet (BD): negative control (NC), probiotic (Pro), and Se-probiotic (Se-Pro) groups. Blood perfusion in the STA and CCA was assessed by Doppler ultrasonography at three different time intervals: at the experimental onset (T0), 3 weeks of dietary supplement (T3), and after 6 weeks of observation (T6). Concomitantly, blood samples were withdrawn for hematobiochemical and hormonal changes. Results revealed no evidence of clinical abnormality, with some enhanced hematological parameters and antioxidant (SOD and GPX) levels in goats of the Se-Pro and Pro groups. High concentrations of FSH were found in the Se-Pro at T6 compared to its values in other groups. Similarly, testosterone levels were elevated in the Pro and Se-Pro groups at T3 compared to other time points. There were significant increases in levels of IGF-1 in the Pro and Se-Pro groups compared to the NC group. Significant (P < 0.05) increases in the values of the blood volume within the CCA and the STA were noted in the Se-Pro group, and the highest values were observed at T6 (CCA, 427.4 ± 33 ml/min; STA, 49.9 ± 5.0 ml/min). In conclusion, supra-nutritional organic selenium improves some hematobiochemical parameters, reproductive hormones, and the blood perfusion within the CCA and STA in goats.

Comparação das artérias carótidas comuns de equinos e muares por ultrassonografia modo-B e Doppler espectral e a relação com a massa corpórea

RESUMO A ultrassonografia convencional e o Doppler espectral nas artérias carótidas comuns em equinos e muares são considerados escassos, diferentemente do que ocorre na medicina humana. Este trabalho propôs comparar as artérias carótidas comuns de equinos e muares por ultrassonografia modo-B e Doppler espectral, além de verificar as diferenças dessas variáveis entre os gêneros desses animais e a relação com a massa corpórea. Foram avaliados os seguintes parâmetros: massa corpórea, diâmetros das artérias, espessura da camada íntima-média (EIM), índice de resistividade (IR), índice de pulsatilidade (IP), velocidade sistólica (VS), velocidade diastólica (VD) e velocidade média (VM). Salvo a massa corpórea, esses parâmetros foram obtidos de três regiões (cranial, médio e caudal) e submetidos à análise conjuntamente. Os diâmetros das artérias carótidas comuns são diferentes entre equinos e muares, com valores menores nos equinos. O IR, o IP, a VS e a VM diferiram entre equinos e muares, sendo maiores nos equinos, e a VD superior nos muares. Não foi observada diferença das variáveis do modo-B e Doppler entre gêneros nos equinos, diferentemente dos muares, cujos machos apresentaram valores maiores do diâmetro, do IR e do IP, mas menores da VS e da VM. A massa corpórea não influenciou as variáveis do modo-B, independentemente do gênero, mas apresenta correlação significativa nas variáveis do modo Doppler. As artérias carótidas comuns de equinos e muares são diferentes pelos exames ultrassonográficos modo-B e Doppler espectral. O gênero não influencia no modo-B e no Doppler nos equinos, porém influencia parcialmente nos muares. A massa corpórea de equinos e de muares, independentemente do gênero, não tem associação com as variáveis do modo-B, apenas com o Doppler.

Fingerprinting of Doppler audio signals from the common carotid artery

Audio fingerprinting involves extraction of quantitative frequency descriptors that can be used for indexing, search and retrieval of audio signals in sound recognition software. We propose a similar approach with medical ultrasonographic Doppler audio signals. Power Doppler periodograms were generated from 84 ultrasonographic Doppler signals from the common carotid arteries in 22 dogs. Frequency features were extracted from each periodogram and included in a principal component analysis (PCA). From this 10 audio samples were pairwise classified as being either similar or dissimilar. These pairings were compared to a similar classification based on standard quantitative parameters used in medical ultrasound and to classification performed by a panel of listeners. The ranking of sound files according to degree of similarity differed between the frequency and conventional classification methods. The panel of listeners had an 88% agreement with the classification based on quantitative frequency features. These findings were significantly different from the score expected by chance (p < 0.001). The results indicate that the proposed frequency based classification has a perceptual relevance for human listeners and that the method is feasible. Audio fingerprinting of medical Doppler signals is potentially useful for indexing and search for similar and dissimilar audio samples in a dataset.

Ultrasonographic Examination of Some Vessels in Dogs and the Characteristics of Blood Flow in These Vessels

The examination by Doppler ultrasonography provides haemodynamic information about blood flow velocity in a respective vessel. It specifies high- and lowresistance flow patterns. The aim of our study was to record the flow in a. carotis communis, a. femoralis and aa. renales in 16 adult clinically healthy dogs of small and medium size; characterize the types of vessels and also determine the pulsatility index (PI) and the resistive index (RI) of these vessels. The a. femoralis is a high-resistance vessel with a pronounced three-peak waveform. The aa. renales gives a typical picture of a low-resistance flow pattern. The characteristics of a. carotis communis involves different images of its branches a. carotis interna and a. carotis externa. In the investigated groups we observed a medium degree of pulsatility (atypical highresistance flow pattern with an absence of reverse flow). The mean measured values of indices for a. carotis communis were: left side PI 1.824 and RI 0.742; right side PI 1.891 and RI 0.746, and for aa. renales: PI 1.366 ± 0.04 and RI 0.684 ± 0.05.