Single-injection caudal thoracic paravertebral block improves pain control and recovery quality in female dogs undergoing unilateral radical mastectomy: a randomized controlled trial.

OBJECTIVE: To test clinical and analgesic effects of a single-injection caudal thoracic paravertebral block (TPVB) after localization of the thoracic paravertebral space with a loss-of-resistance to air injection technique in female dogs undergoing unilateral radical mastectomy. ANIMALS: 14 client-owned dogs. PROCEDURES: Dogs were premedicated with methadone, anesthetized with propofol and sevoflurane, and randomly assigned to receive a TPVB or no block preoperatively. Rescue analgesia with fentanyl and methadone was provided on the basis of cardiovascular responses during surgery and postoperative pain scores assigned with a validated pain scale. Required dose of rescue opioids; mean end-tidal sevoflurane concentration; episodes of hypotension, bradycardia, and other complications; quality of recovery scores; and postoperative pain scores were compared between groups. RESULTS: Median intraoperative fentanyl doses were 0 µg/kg (range, 0 to 2 µg/kg) and 4 µg/kg (range, 2 to 6 µg/kg) for the TPVB and control groups, respectively. Median postoperative methadone doses were 0 mg/kg (range, 0 to 0.2 mg/kg) and 0.6 mg/kg (range, 0.4 to 0.6 mg/kg) for the TPVB and control groups, respectively. Recovery scores and pain scores assigned at the time of and 1 hour after extubation were significantly lower in the TPVB group than in the control group. CONCLUSIONS AND CLINICAL RELEVANCE: A single-injection caudal TPVB improved pain control and recovery quality in female dogs undergoing unilateral radical mastectomy. Because the TPVB involves only a single injection, does not take long to perform, and requires only readily available low-cost equipment, the technique may be a valuable option in both referral and first-opinion practice.

Mastectomy in 25 small ruminants (2002-2019).

OBJECTIVE: To describe the outcome of small ruminants treated with unilateral and bilateral mastectomy by using three surgical techniques. STUDY DESIGN: Retrospective study. ANIMALS: Twenty-five small ruminants (24 goats and one sheep). METHODS: Medical records of animals that underwent mastectomy between November 1, 2002, and May 1, 2019, were reviewed. Follow-up information was obtained by telephone questionnaire with owners. Signalment, surgical data, intraoperative and postoperative complications, bacterial culture results, histopathologic diagnoses, short- and long-term outcomes, and other procedures performed were recorded. RESULT: Procedures consisted of six unilateral (with an elliptical incision) and 19 total (with inverted cloverleaf or elliptical skin incisions) mastectomies. All animals survived to hospital discharge. Intraoperative complications included contamination of the surgical site with mammary-gland fluid, hemorrhage, and difficulty dissecting skin from the mammary gland. Postoperative complications included seroma formation (7/25), surgical-site infection (5/25), and dehiscence of the skin incision (3/25). Mammary neoplasia was diagnosed in seven of 15 animals with histopathologic examination. No association was detected between surgical technique, diagnosis of neoplasia, and long-term outcome. Overall, client satisfaction was high. CONCLUSION: Mastectomy was effective at removing abnormally enlarged udders secondary to chronic mastitis, inappropriate lactation, idiopathic causes, or neoplasia and was associated with a low rate of complications in small ruminants. CLINICAL SIGNIFICANCE: Unilateral mastectomy with an elliptical skin incision or total mastectomy, preferably with inverted cloverleaf skin incision, may be indicated to remove diseased mammary tissue in small ruminants and can result in long-term survival with low morbidity and cosmetically pleasing results.

Botulinum toxin type A as an adjunct in postoperative pain management in dogs undergoing radical mastectomy.

The aim of this randomised placebo-controlled, observer-blinded study was to evaluate the analgesic effects of botulinum toxin type A (BoNT-A) as an adjunct for postoperative pain control in dogs. Sixteen dogs undergoing bilateral radical mastectomy for treatment of mammary tumours were enrolled. Twenty-four hours before surgery, the subjects were distributed into two groups of eight dogs each: 7 iu/kg BoNT-A (BoNT-A) or saline (Control) was administered subcutaneously in each mammary gland. Following sedation with intramuscular 0.03 mg/kg acepromazine and 0.3 mg/kg morphine, anaesthesia was induced intravenously with 4 mg/kg propofol and maintained with isoflurane/O2. Postoperative analgesia was evaluated for 72 hours after extubation using the Visual Analogue Scale (VAS) and modified Glasgow Composite Measure Pain Scale (modified-GCMPS). Rescue analgesia was provided with intramuscular morphine (0.5 mg/kg). Data were analysed using analysis of variance, Tukey's test, Mann-Whitney U test and Friedman test (P<0.05). The pain scores were significantly lower in the BoNT-A than in the Control from 8 hours to 60 hours and from 12 hours to 60 hours after extubation, based on the VAS and modified-GCMPS, respectively. Rescue analgesia was required by significantly more dogs in the Control (7/8) compared with the BoNT-A (2/8) (P=0.022). Pre-emptive BoNT-A appears to be effective as an adjuvant for postoperative pain management in dogs undergoing bilateral radical mastectomy.

Surgical stress and postoperative complications related to regional and radical mastectomy in dogs.

BACKGROUND: 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. RESULTS: 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. CONCLUSION: 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.

Adjuvant chemotherapy with mitoxantrone for cats with mammary carcinomas treated with radical mastectomy.

OBJECTIVES: The purpose of this study was to investigate the disease-free interval, survival time and adverse events of a combined treatment approach in cats with mammary malignant tumors using radical mastectomy and adjuvant mitoxantrone. METHODS: All cats underwent surgery to remove the mammary chain containing the tumors. A 3 cm margin was obtained around removed tumors. For staging purposes, regional inguinal lymphadenectomy was performed in all cases. After histopathology, cats were staged according to the World Health Organization's (WHO) staging system. Chemotherapy with mitoxantrone was started 15-30 days after surgery (6 mg/m(2) IV every 21 days for four cycles) with the objective of delaying metastasis. RESULTS: Three cats were intact, one cat was early spayed, four cats were late spayed and four cats were spayed at an unknown age. Based on the WHO's staging system, six cats were classified as stage I and six cats as stage III. The median disease-free interval and survival time were 360 and 480 days, respectively. Four (33%) cats received four doses of mitoxantrone, four (33%) cats received three doses and four (33%) cats received only one dose. The most frequent adverse effects of chemotherapy were azotemia, anorexia, leukopenia and vomiting. CONCLUSIONS AND RELEVANCE: Adjuvant mitoxantrone chemotherapy may be an option for feline mammary tumors. Further, sufficiently powered, randomized prospective trials are necessary to determine if mitoxantrone is superior, inferior or equivalent to doxorubicin in the adjuvant setting.

Postoperative treatment outcome in canine mammary tumors. Multivariate analysis of the prognostic value of pre- and postoperatively available information.

OBJECTIVE: Mammary tumors belong to the most common canine neoplasias. Few data are available on postoperative outcome and independent prognostic value of variables including pre-operatively available parameters such as cytology. The aim of this study was to characterize outcome following surgery and identify independent prognostic factors in canine mammary tumors. MATERIAL AND METHODS: Prospective study in which dogs with mammary tumors underwent surgical tumor removal followed by histopathologic examination of the neoplasias. Kaplan-Meier log rank analysis and multivariate regression analyses were used to evaluate survival, recurrence-free interval (RFI) and metastasis free interval (MFI) as well as independent influence of variables on outcome. RESULTS: 134 dogs with mammary tumors were included. In 126 dogs without distant metastasis, overall survival duration was 1113 d; median RFI and MFI were not reached. Histologic grade showed independent influence on duration of RFI (p=0.040), MFI (p=0.007), and survival (p=0.029). Median survival in benign (n=98), grade 1 (n=10) and grade 2 (n=16) malignant tumors was 1319 d, 670 d, 406 d, respectively. Cytology exerted independent influence on the likelihood for recurrence (p=0.013), duration of RFI (p=0.026) and survival (p=0.030). CONCLUSION AND CLINICAL RELEVANCE: Histologic grade was of independent prognostic significance for postoperative outcome in this population of dogs with mammary tumors. As a pre-operatively available parameter, cytology may also possess prognostic value in canine mammary neoplasias.

Mammary tumor recurrence in bitches after regional mastectomy.

OBJECTIVES: To investigate the histologic diagnosis and incidence of new mammary tumor growth in the remaining mammary chain tissue after regional mastectomy. STUDY DESIGN: Prospective clinical study. ANIMALS: Female dogs (n=99) that had excision of a single mammary tumor. METHODS: Female dogs that had regional mastectomy to remove a single tumor were followed for >or=1 year postoperatively. Data regarding tumor type, tumor recurrence, and development of metastasis were recorded. RESULTS: Fifty-seven (58%) dogs developed a new tumor in the ipsilateral mammary chain after the 1st surgery; 77% had repeat surgery. There was no significant correlation between the time to new tumor development and the histologic diagnosis for the 1st and 2nd tumor types. In 31 dogs, the histologic diagnosis for initial and subsequent tumors was identical and there was a significant correlation such that dogs with an initial malignant tumor are likely to develop another malignant tumor (P=.0089). The histologic classification of the new tumor was likely to be malignant if it was located close to the side where the initial tumor had been removed (P=.026). CONCLUSIONS: Our results show that 58% of dogs developed a new tumor in the remaining mammary glands of the ipsilateral chain after regional mastectomy for removal of a single tumor. CLINICAL RELEVANCE: This should be taken into account when deciding on the surgical management (radical or regional mastectomy) in dogs with single mammary tumors.

Are complex carcinoma of the feline mammary gland and other invasive mammary carcinoma identical tumours? Comparison of clinicopathologic features, DNA ploidy and follow up.

Feline mammary carcinomas are known for their unfavourable prognosis due to a strong tendency to local recurrence and metastasis. We studied 73 spontaneous primary mammary carcinomas and identified eight cases presenting a biphasic nature, with neoplastic epithelial and myoepithelial cells (complex carcinoma). These cases presented histopathologic features associated with a better prognosis; they were also associated with higher overall survival and disease-free survival rates compared to other common invasive mammary carcinomas of non-specified type. Complex carcinoma appears to be a low-grade malignancy.

Radical mastectomy in 20 ruminants.

OBJECTIVE: To describe a surgical technique for radical mastectomy in ruminants and to report experience and outcome in 20 animals. STUDY DESIGN: Retrospective study. ANIMALS: Seventeen goats and 3 cows. METHODS: Medical records of ruminants that had radical mastectomy between June 1, 1987 and June 1, 2003 were reviewed. Follow-up information was obtained by telephone interview of owners. RESULTS: One animal died within 24 hours from complications of gangrenous mastitis and another died from necrotizing cellulitis. Eighteen animals were discharged and follow-up information was available for 15 animals; 12 animals lived at least 1 year postoperatively. CONCLUSIONS: Ruminants with severe but localized diseases of the udder did well after radical mastectomy. The procedure was well tolerated, made the animals more comfortable, and potentially prolonged their lives as pets. CLINICAL RELEVANCE: Radical mastectomy can be a safe and effective procedure for ruminants with udder disease, with few complications.

A spontaneously occuring mammary gland ductal carcinoma in situ in a rhesus macaque (Macaca mulatta) and a review of spontaneous mammary gland tumors in rhesus monkeys.

A spontaneous mammary gland ductal carcinoma in situ was diagnosed in a 6-8-year-old female rhesus macaque (Macaca mulatta). To our knowledge, this is only the tenth case of spontaneous mammary gland tumors to be reported in rhesus monkeys. Despite the paucity of case reports, several theories exist to explain the occurrence of mammary tumors. The Mason Pfizer monkey virus, a type D retrovirus similar to the virus that causes simian acquired immunodeficiency syndrome, has been implicated as a possible etiologic agent. Because this virus has been isolated from normal primate mammary tissue, it is unlikely to be the sole etiologic agent. Other theories include the tumorogenic effects that androgens, growth hormones, irradiation, and aging have on the mammary gland.

[Mammary carcinoma of the female dog: clinical relevance of the immunohistochemical demonstration of micrometastases in the regional lymph nodes]. / Mammakarzinom der Hündin: Klinische Bedeutung der immunhistochemisch nachgewiesenen Mikrometastasen in den regionären Lymphknoten.

77 formalin-fixed and paraffin-embedded mammary carcinomas and the regional lymph nodes of bitches were examined by immunocytochemical technique, all of them free of metastases in routine HE-staining. To compare the two methods, two serial sections were cut of three parts of the lymph nodes. One was used for incubation with the antibody AE1, which reacts with cytokeratin subtype I/A, the other for staining with HE. From 60 of the 77 bitches we received information about the operation and the follow up study period (surgical method, new tumours, survival rate and causes of death). These data were compared with the immunocytochemical results of the lymph nodes. In 84.4% of all 77 lymph nodes tumour cell embolism and/or micrometastases were detected. Comparing the two methods, we found that with HE-staining it was only possible to detect two thirds of all micrometastases containing more than 50 tumor cells. Smaller micrometastases were suspicious in a few cases, the majority could not be detected at all. In the follow up study there was evidence of a better prognosis for bitches with tumours detected in an early stage of growth and treated with radical mastectomy. This was independent of a positive or negative result of tumour cells in lymph nodes. The presence of cancer cells in lymph nodes was only important, if either the tumour was treated in an advanced stage or only single complexes or tumour nodes were extirpated. These dogs often showed metastases in the lung.