ABSTRACT
The application of high-intensity ultrasound waves has been investigated as one of the non-invasive methods of contraception in several species. This study was aimed to investigate the mechanism of contraception in dogs using ultrasound waves by measuring acute-phase proteins and oxidative stress indices. Ten mixed-breed adult and fertile dogs were divided into two equal treatment and control groups. The dogs' testes in the treatment group were exposed to ultrasound waves at an intensity of 1.5 W/cm2 and a frequency of 1 MHz, 3 times for 5 min, and every 48 h. Blood sampling (before exposure, and 3, 5, 7, 21, 35, 49, and 63 days after exposure), semen collection (before exposure, and 4, 6, and 8 weeks after exposure), testicular ultrasonography (before exposure, and 4, 6, and 8 weeks after exposure), and testis histopathology (30 and 60 days after exposure) were performed during the study. The echogenicity of the dogs' testes significantly increased in the treatment group from week 6 onwards (P = 0.001). The concentration and progressive motility of spermatozoa in all samples, from both the control and the treatment groups, were normal at different times during the study. There was no significant change in the concentration of serum testosterone. The activity of superoxide dismutase and glutathione peroxidase enzymes on days 3, 5, and 7 and catalase activity on day 3 significantly decreased in the treatment group compared to those of the control group (P = 0.006). In addition, malondialdehyde concentration significantly increased in the treatment group on days 3, 5, and 7 (P < 0.0001). The concentrations of C-reactive protein, serum amyloid A, and alpha-1-acid glycoprotein significantly increased on days 3, 5, and 7 compared to those of the control group (P = 0.005). To sum up, high-intensity ultrasound waves could activate the process of the acute phase response of inflammation and oxidative stress and induce further damage to the testicular tissue in dogs. This was mainly observed in the first week after the testes were exposed to ultrasound waves.
