Factors influencing complications following mastectomy procedures in dogs with mammary gland tumors: 140 cases (2009-2015).

OBJECTIVE: To evaluate complication rates for various types of mastectomy procedures, identify factors associated with an increased risk of complications, and determine the consequences of such complications. ANIMALS: 140 female dogs that underwent 154 separate mastectomy procedures to treat mammary gland tumors. PROCEDURES: Medical records of dogs in the Penn Vet Shelter Canine Mammary Tumor Program from July 2009 to March 2015 were reviewed. Data regarding signalment, tumor characteristics (ie, number and size, benign or malignant, and bilateral or unilateral), mastectomy type, anesthesia time, concurrent ovariohysterectomy or ovariectomy, surgeons' qualifications, antimicrobial administration after surgery, postoperative placement of surgical drains, and complications (seroma, abscess, dehiscence, or infection) were collected. Complications that required hospitalization were recorded. Fisher exact tests were used to evaluate associations between variables of interest and complications. Multivariable analysis was used to identify factors independently associated with an increased risk of complications. RESULTS: Complication rate following all mastectomy procedures was 16.9% (26/154); of these, 9 (34.6%) required hospitalization. High body weight, undergoing bilateral mastectomy, and postoperative antimicrobial administration were associated with significantly increased odds of complications. The odds of complications associated with postoperative antimicrobial administration, however, varied according to mastectomy type; dogs undergoing chain mastectomy that did not receive antimicrobials postoperatively had the highest odds of developing complications. Dogs undergoing concurrent ovariohysterectomy or ovariectomy had significantly decreased odds of complications. CONCLUSIONS AND CLINICAL RELEVANCE: Previously spayed dogs with a large body size that underwent the most extensive mastectomy procedures had increased odds of having postoperative complications.

A prospective randomized trial of desmopressin in canine mammary carcinoma.

Metastatic disease represents a serious and often fatal development in patients with solid tumours, including women with breast cancer and dogs with mammary tumours. Therefore, preventing and treating metastatic disease has remained a priority in cancer research. Desmopressin, a synthetic derivative of vasopressin, traditionally used to treat patients with bleeding disorders, has been proposed as a potential anti-metastatic agent due to its effect on haemostasis as well as multiple other anti-proliferative and anti-angiogenic mechanisms. The purpose of this study was to retest desmopressin in dogs with mammary carcinomas. A prospective randomized study was performed. Twenty-four dogs with mammary carcinomas were enrolled; 12 dogs received perioperative desmopressin and 12 received placebo. All dogs underwent standard pre-surgical staging followed by complete resection of all tumours. Intact dogs were spayed. All tumours were graded and classified according to the published guidelines. Follow-up was performed every 4 months the first year and every 6 months thereafter. Necropsies were requested on all dogs. There was no difference in time to primary metastasis or survival between desmopressin treated dogs and the placebo arm (P = .43 and .73, respectively). The distribution of negative prognostic factors, including tumour grade, stage, and high vs low bioscore (refined flexible bioscoring) category between arms was not statistically different, even though more dogs in the placebo arm had grade 3 tumours and high bioscores. Based on the results of this study, perioperative desmopressin does not prevent metastasis in dogs with mammary carcinomas.