Effects of short-term administration of melatonin before gonadectomy on oxidative stress, cortisol and sex hormones in male dogs.

The aim of this study was to investigate gonadectomy stress, steroid hormones and serotonin in male dogs treated with melatonin before gonadectomy. Twenty-five mixed breed adult dogs were divided into five equal groups. The melatonin and melatonin + gonadectomized groups received melatonin treatment (3 mg/10 Kg, PO, TID) the day before gonadectomy; the gonadectomized and anaesthesia groups did not receive melatonin; and the control group just received the melatonin vehicle. Blood sampling was performed before melatonin administration (day -1) and on days 0 (gonadectomy), 1, 3 and 6 after gonadectomy. Superoxide dismutase and glutathione peroxidase concentrations decreased significantly in gonadectomized dogs compared with dogs treated with melatonin before gonadectomy and intact dogs. Gonadectomy led to a significant decrease in catalase concentration in gonadectomized dogs compared with other study groups. Malondialdehyde levels increased significantly in gonadectomized dogs compared with other groups. Melatonin administration before gonadectomy led to decreased malondialdehyde concentration in gonadectomized and intact dogs compared to the control group. Cortisol concentration increased significantly in gonadectomized dogs compared to the control dogs. Serotonin levels decreased in gonadectomized dogs, but melatonin treatment increased serotonin concentration in gonadectomized and intact dogs. Melatonin treatment before gonadectomy suppressed oxidative stress and the cortisol but increased serotonin level.

Echotexture Analysis of Prostate Parenchyma for Detection of Benign Prostatic Hyperplasia in Dogs.

Ultrasonography is one of the most common methods for the diagnosis of prostate disorders, such as benign prostatic hyperplasia (BPH), in dogs. Changes in the echotexture are one of the indicators used to diagnose prostate disorders. The purpose of this study was to investigate the changes occurred in the dogs' prostate echotexture during the induction of BPH using image analysis. Twenty sexually mature male intact mixed-breed dogs were selected and divided randomly into control and BPH-induced groups. BPH was induced using testosterone and estrogen injections for 63 days. The ultrasound imaging of the dogs' prostate was performed during the induction of BPH on days 0, 21, 42, and 63. The echotexture of the prostate parenchyma was analyzed using the Image J software. Then, the changes in the echotexture and its correlation and linear regression with the prostate volume and canine prostate specific esterase (CPSE) concentration were evaluated by statistical tests. The prostate parenchyma echotexture did not show any significant changes during the induction of BPH and in comparison with that of the control group. While prostate volume and CPSE concentration increased significantly, indicating that BPH was induced in the dogs. There was no significant correlation and linear regression between the prostate echotexture and prostate volume or between the CPSE concentration and prostate echotexture. According to the results, the alteration in the prostate parenchymal echotexture did not occur in the early stages of induced BPH, but significant changes occurred in the prostate volume and CPSE concentration during those early stages.