Regional differences of testicular artery blood flow in post pubertal and pre-pubertal dogs

Abstract

BackgroundMeasurement of testicular artery blood flow is used in several species to evaluate reproductive function and testicular and scrotal pathology. In dogs there are inconsistent reports about normal flow in post-pubertal dogs and no information concerning pre-pubertal dogs. The aim of this study was to describe regional differences in testicular artery blood flow in clinically normal post-pubertal and pre-pubertal dogs with no history of reproductive tract disease.ResultsThe post-pubertal dogs produced normal ejaculates throughout the study. In all dogs the three different regions of the artery were imaged and monophasic flow with an obvious systolic peak and flow throughout diastole was observed on every occasion. The highest peak systolic velocity (PSV) and end diastolic velocity (EDV) were measured within the distal supra-testicular artery and marginal artery whilst the lowest PSV and EDV were measured within the intra-testicular arteries. Flow measurements were not different between left and right testes and were consistent between dogs on different examination days. Calculated resistance index (RI) and pulsatility index (PI) were lowest in the intra-testicular arteries.The pre-pubertal dogs had significantly smaller testes than the post-pubertal dogs (p < 0.05) and were unable to ejaculate during the study. The three different artery regions were imaged at every examination time point, and flow profiles had a similar appearance to those of the post-pubertal dogs. PSV, EDV, RI and PI showed a similar trend to the post-pubertal dogs in that values were lowest in the intra-testicular arteries. Notably, values of PSV, EDV, RI and PI were significantly lower (p < 0.05) in pre-pubertal dogs compared with post-pubertal dogs.ConclusionsThis study demonstrated important regional and pubertal differences in testicular artery blood flow of dogs, and form the basis for establishing baseline reference values that may be employed for the purposes of clinical diagnosis.

Examination of jackass (Equus asinus) accessory sex glands by B‐mode ultrasound and of testicular artery blood flow by colour pulsed‐wave Doppler ultrasound: Correlations with semen production

“…As already reported in stallions (Ortiz‐Rodriguez et al., ), bulls (Gloria et al, ) and dogs (Zelli, Troisi, Elad Ngonput, Cardinali, & Polisca, ), the values of the testicular artery blood flow variables were similar in the right and left testis. The present blood flow results are also comparable to those described in stallions (Ortiz‐Rodriguez et al, ), bulls (Gloria et al, ), dogs (de Souza, Barbosa, et al, ) and camels (Kutzler, Tyson, Grimes, & Timm, ). Certainly, the RI and PI in the stallion are similar to those recorded here.…”

“…Rota et al () described the blood flow in the testicular artery of prepubertal jackasses and found a pronounced difference with the values recorded on their reaching puberty (24 months). The same has been reported in dogs (de Souza, Barbosa, et al, ). However, both these studies involved measurements being taken only at a single point.…”

“…In the present work, the different glands were more easily detected than earlier described for the jackass (Contri et al, 2008;Kandiel & Shafey, 2017), perhaps due to the relatively large size of the Catalonian donkey breed. The PROS, BUG and AMP were significantly larger in the present animals than in similar sized stallions (Pozor & McDonnell, 2002), but the VG were thinner with no visible lumen.…”

“…Despite these advantages, ultrasound has been little used, however, to study the jackass male reproductive tract. Contri et al (2008) briefly examined the difference in ASG dimensions before and after ejaculation using B-mode ultrasound, while Kandiel and Shafey (2017) used the same to provide a detailed description of the glands' anatomy and echogenicity in animals of different age. In addition, Rota et al (2018) used colour pulsed-wave Doppler ultrasound to examine the correlation between testicular artery blood flow and the attainment of puberty.…”

Ultrasonography of the prostate gland and testes in dogs

“…High velocities are present within the supratesticular region, which decrease through the marginal and intratesticular regions. Also, these parameters are different in postpubertal and prepubertal dogs (de Souza and others 2015) and in dogs of different sizes (Souza and others 2014). …”