Surgery is the treatment of choice for regional control of mammary neoplasms in female dogs. Various surgical techniques may be used, as long as mammary gland anatomy, lymphatic drainage, and known prognostic factors are respected. The purpose of this study was to compare surgical stress—including duration of surgery, nociception and hematological changes—and postoperative complications in dogs undergoing regional and unilateral radical mastectomy. Eighteen dogs were selected for each technique. Postoperative pain (nociception), hematological changes, and postoperative complications were compared between the two groups. The group treated with radical mastectomy had a longer surgical duration, showed more intense physiological changes, achieved higher scores on nociception scales, and experienced more postoperative complications. Compared to regional mastectomy, radical mastectomy was associated with longer surgical duration, greater nociceptive stimulus, greater surgical stress, and higher incidence of postoperative complications in dogs. Although evaluation of long-term results was not a goal of this study, it is suggested that postoperative recovery and patient quality of life should be considered when choosing a surgical approach for treating mammary tumors in dogs.

Background: Mammary tumors are among the most frequent neoplasms in female dogs, but the strategies employed in animal treatment are limited. In human medicine, hormone manipulation is used in cancer therapy. Tamoxifen citrate is a selective inhibitor of oestrogen receptors and exerts a potent anti-oestrogen effect on the mammary gland. The aim of this study was to evaluate the adverse effects when exposing healthy female dogs to tamoxifen.Methods: Tamoxifen was administered for 120 days at a dose of 0.5 or 0.8 mg/kg/day to either intact or spayed female dogs. The effects were assessed through clinical examination, haematology, serum biochemistry, ophthalmology and bone marrow aspirate examination. Ovariohysterectomy was performed and the uterus examined by histopathology.Results: Vulva oedema and purulent vaginal discharge developed with 10 days of tamoxifen exposure in all groups. Pyometra was diagnosed after around 90 days of exposure in intact females with frequencies increasing during the following 30 days of exposure. Up to 50% of dogs within the groups developed retinitis but none of the dogs had signs of reduced visual acuity. The prevalence of retinitis in each group was similar after 120 days of exposure. Haematological, biochemical and bone marrow changes were not observed. Due to the high risk of developing pyometra after prolonged exposure to tamoxifen, only spayed animals should be given this medication.Conclusions: A dose of 0.8 mg tamoxifen/kg body weight/day is recommended when treating tamoxifen-responsive canine mammary tumors. Due to the high risk of developing pyometra, ovariohysterectomy is recommended.

Pyometra is a common disease in intact female dogs and can cause glomerulopathy and tubular injury. This study aimed to evaluate kidney injury in female dogs with pyometra, as well as progression of the injury during treatment and the markers of this condition. This study analyzed 20 intact female dogs with both clinical and sonographic diagnosis of pyometra. Dogs were treated with intravenous fluids and antibiotics, and an ovariohysterectomy was performed. The following parameters were assessed at eight separate time points: blood pressure; serum creatinine, phosphorus, and urea levels; urinalysis and urinary biochemical parameters [urinary gamma-glutamyl transferase (uGGT) and urinary protein-to-creatinine ratio (UPCR)]; glomerular filtration rate (GFR); and urine output. All dogs showed some degree of kidney injury at the time of pyometra diagnosis. This was transient in most animals, resolving with treatment of the pyometra. Measurement of uGGT and UPCR identified renal parenchymal injury, helping to determine the prognosis of the animals analyzed in the present study.