Platelet count and MCHC as independent prognostic markers for feline mammary carcinomas.

Mammary neoplasms are common in felines species and represent a significant disease for its unfavorable prognosis. Changes in the blood count and serum biochemical profile of these patients have potential as non-invasive prognostic markers prior to mastectomy, however, they are poorly described in literature. In this study univariate and multivariate analyses were performed using these factors to determine the effect of each parameter on the one-year survival time after the surgical procedure in these animals. The median overall survival (OS) and the disease-free survival (DFS) were 365 and 242 days, respectively. In univariate analysis, values within the reference range of monocyte, platelet and creatinine counts were identified as significant prognostic factors for OS and only creatinine was significant for DFS (P < 0.05). In the multivariate analysis, platelets and mean corpuscular hemoglobin concentration (MCHC) remained independent prognostic factors for OS. The results presented suggest that monocytes, platelets and creatinine may be important non-invasive pre-surgical prognostic markers, and that platelet count and MCHC are independent prognostic markers for feline mammary carcinomas (FMC). The correlation between such alterations is of important relevance for veterinary oncology, and prospective studies are needed to validate their clinical use and that platelet count and MCHC are independent prognostic markers for FMC. The results found in this study can also be studied in human medicine, regarding blood markers in human breast cancer (HBC).

Topoisomerase IIα immunoexpression in feline mammary carcinomas: A correlation with Ki67 immunoexpression and the mitotic count.

The aim of the study was to compare the immunohistochemical expression of topoisomerase IIα protein (Topo IIα) with Ki67 expression and mitotic count in feline mammary carcinomas (FMCs). Topo IIα is considered as a proliferation indicator as well as a molecular target of anthracycline chemotherapy. The studied material included 70 FMCs from female cats treated with mastectomy. Primary mouse monoclonal antibodies directed against Topo IIα and Ki67 were used in immunohistochemical reactions. The number of mitotic figures was counted at 400× magnification in a field of 2.37 mm2. Immunohistochemical reaction for Topo IIα occurred in cell nuclei. The Topo IIα index ranged from 6.12% to 54.60% and was positively correlated with the values of the Ki67 index (r = 0.7193) and the mitotic count (r = 0. 2858). This indicates the potential possibility of use of the immunohistochemical expression of Topo IIα to assess the rate of proliferation in FMCs. The wide range of expression of Topo IIα in individual tumorus found in the conducted studies allows us to hypothesize that its assessment could be used as a predictive marker in chemotherapy of FMCs with the use of anthracyclines. However, this requires confirmation in clinical trials.

Surgical dose and the clinical outcome in the treatment of mammary gland tumours in female dogs: a literature review.

Mammary gland tumours are the most frequent tumours in intact female dogs and surgery remains the main treatment modality. Surgery is traditionally performed according to the lymphatic drainage of the mammary glands, but robust evidence is still lacking on what surgical dose is the smallest and results in the best outcome. The objective of the study was to investigate whether choice of surgical dose influences treatment outcome in dogs with mammary tumours and to identify current gaps in research that need to be filled in future studies for identifying the smallest surgical dose with the best possible outcome. Articles for entrance into the study were identified in online databases. Information regarding outcome following use of different surgical doses was extracted for analysis. Also, known prognostic factors were mapped for each study to discuss their impact on treatment outcome. Twelve articles were identified and included. Surgical dose applied ranged from lumpectomy to radical mastectomy. Radical mastectomy was most often analysed [11/12 (92%) articles]. Less invasive surgical doses were used less often in decreasing order of invasiveness. Outcomes analysed were most often survival time [7/12 (58%) articles], frequency of recurrences [5/12 (50%) studies] and time to recurrence [5/12 (42%) studies)]. No studies demonstrated any significant association between surgical dose and outcome. Gaps in the research could be categorised as data that was not available for extraction, for example known prognostic factors. Other factors related to study design were also identified, for example small groups of dogs included into the study. No studies showed a clear benefit of choosing one surgical dose over the other. Choice of surgical dose should be based on known prognostic factors and risks for complications rather than on lymphatic drainage. In future studies all prognostic factors should be included when investigating how choice of surgical dose influences treatment outcome.

Goats diagnosed with neoplasia display variability in clinical presentations, treatments, and outcomes.

OBJECTIVE: To describe clinical presentation, treatment, and short- and long-term outcomes of goats diagnosed with neoplasia. ANIMALS: 46 goats with a definitive diagnosis of ≥ 1 neoplastic process admitted over a 15-year period. PROCEDURES: Medical records for all goats admitted to the Colorado State University Veterinary Teaching Hospital over a 15-year period were reviewed to identify animals diagnosed with neoplasia. Signalment, presenting complaint, duration of clinical signs, diagnostic testing, treatment, and short-term outcomes were recorded. When available, long-term follow-up data were collected via email or telephone interview with owners. RESULTS: 46 goats with 58 neoplasms were identified. The prevalence of neoplasia within the study population was 3.2%. The most commonly diagnosed neoplasms were squamous cell carcinoma, thymoma, and mammary carcinoma. The Saanen breed was the most common breed noted in the study population. Evidence of metastasis was found in 7% of the goats. Long-term follow-up was available in 5 goats with mammary neoplasia that underwent bilateral mastectomy. No evidence of mass regrowth or metastasis was noted in any of the goats 5 to 34 months postoperatively. CLINICAL RELEVANCE: Goats are increasingly treated as companion rather than strictly production animals, making it important for veterinarians to provide more evidence-based and advanced clinical care. This study provided a clinical overview of presentation, treatment, and outcome for goats diagnosed with neoplasia and highlighted the challenges associated with the wide variety of neoplastic processes affecting goats.

MAMMARY GLAND ADENOCARCINOMA IN FOUR INDIAN CRESTED PORCUPINES (HYSTRIX INDICA).

Neoplasia in porcupines is rarely reported in the literature, and the prevalence is unknown. A retrospective review of records from a private zoo diagnostic pathology service found four cases of mammary adenocarcinoma in Indian crested porcupines (Hystrix indica) from four separate zoological institutions. All cases presented in geriatric females (14-19 yr of age) as freely movable subcutaneous masses within the mammary chain. None of the individuals had additional clinical signs, radiographic, or hematologic changes at initial presentation. All cases were managed with surgical excision in the form of either an excisional biopsy or a partial mastectomy. Histologic examination diagnosed all tumors with anaplasia and moderate to high numbers of mitotic figures. Two cases required subsequent surgeries for management of local recurrence in the years following initial diagnosis. One case is 19 months postsurgical removal without evidence of metastasis or local recurrence. Two of the cases were euthanized after diagnosis of inoperable metastases to the lungs and spinal cord, including one previously treated with an oral nonsteroidal antiestrogen medication, tamoxifen. The third case was euthanized due to degenerative mobility changes and renal dysfunction and had no evidence of metastasis. The average survival time from initial surgical excision to euthanasia for the three applicable cases was 33 months. These cases suggest that surgical excision alone may result in temporary management of mammary adenocarcinoma in this species. Metastasis can occur, and routine screening with advanced imaging may aid in early detection of these lesions.

Influence of Constant Rate Infusions of Fentanyl Alone or in Combination With Lidocaine and Ketamine on the Response to Surgery and Postoperative Pain in Isoflurane Anesthetized Dogs Undergoing Unilateral Mastectomy: A Randomized Clinical Trial.

The aim of this study was to compare the effects of constant rate infusions (CRI) of fentanyl alone or combined with lidocaine and ketamine (FLK), on physiological parameters, isoflurane requirements and the number of postoperative analgesic rescues in dogs undergoing unilateral mastectomy. Twenty-two dogs were premedicated with acepromazine 0.02 mg/kg and morphine 0.5 mg/kg and anesthetized with propofol and isoflurane. Dogs were randomly assigned to 1 of 2 groups: Fentanyl group (fentanyl 5 µg/kg loading dose [LD] and 9 µg/kg/h CRI; n = 11); FLK group (fentanyl [same doses]; lidocaine 2 mg/kg LD and 3 mg/kg/h CRI; ketamine 1.0 mg/kg LD and 0.6 mg/kg/h CRI; = 11). Intraoperative evaluations were performed before the start of surgery and administration of the treatments (T0); three minutes after the LD (T1); during incision and tissue divulsion (T2); during closure of the surgical wound (T3). Meloxicam (0.1 mg/kg) was administered at T3. Blood samples were collected for determination of plasma concentrations of fentanyl, lidocaine and ketamine. Pain scores and the number of postoperative analgesic rescues with morphine (0.5 mg/kg) were evaluated for 24 hours postoperatively using the short form of the Glasgow Composite Measure Pain Scale. Compared to T0, significant decreases in heart rate (from 84 ± 28 to 53 ± 16 bpm in the Fentanyl group and from 93 ± 16 to 63 ± 15 bpm in FLK) and mean arterial pressure (from 61 ± 5 to 49 ± 10 mmHg in Fentanyl and from 59 ± 3 to 38 ± 6 mmHg in FLK) were observed at T1. Arterial hypotension was transient, with normalization of values at T2 and T3. The expired fraction of isoflurane did not differ significantly between the groups. Plasma concentrations of fentanyl, lidocaine and ketamine remained within the therapeutic range. Postoperatively, the number of dogs requiring analgesic rescue was significantly lower in the FLK (0/11, 0%) than in the Fentanyl group (5/11, 45%). In dogs administered morphine and meloxicam as part of the anesthesia protocol, an intraoperative CRI of FLK abolished the requirement for postoperative analgesic rescue for 24 hours in dogs undergoing mastectomy.

Analgesic, cardiorespiratory effects and motor block characteristics of epidural levobupivacaine alone or in combination with methadone or dexmedetomidine in bitches undergoing unilateral total mastectomy.

The aim of this study was to evaluate the latency, extent of analgesia, and duration of motor block of levobupivacaine alone and combined with methadone or dexmedetomidine after epidural administration during and after mastectomy in dogs. Twenty-four mature, mixed-breed female dogs were randomly divided into three experimental groups with eight animals each, according to the agents used in lumbosacral epidural analgesia: levobupivacaine 0.75% alone (1.5mg/kg - control group), levobupivacaine 0.75% (1.5 mg/kg) + methadone 1% (0.3 mg/kg), or levobupivacaine 0.75% (1.5 mg/kg) + dexmedetomidine 0.05% (3 µg/kg). During surgery, cardiorespiratory parameters were evaluated. Rescue analgesia was given when there were signs of nociception and was necessary in all three treatment groups. Since all animals received rescue analgesia during the surgery and immediately post-surgery, the duration of the sensitive block were not evaluated. The extent of sensory block was between the 12º and 13º thoracic vertebrae for the control group, 7º thoracic vertebra to 5º lumbar vertebra (methadone group), and 8º thoracic vertebra to 4º lumbar vertebra for the dexmedetomidine group. Methadone or dexmedetomidine combined with levobupivacaine increased the extent of the sensory block and the duration of the motor block in bitches when administered via the epidural route.

Plasma concentration, cardiorespiratory and analgesic effects of ketamine-fentanyl infusion in dogs submitted to mastectomy.

BACKGROUND: The analgesic and cardiorespiratory effects of ketamine, fentanyl, or ketamine-fentanyl constant rate infusion (CRI) in dogs undergoing mastectomy were evaluated. Seventeen female dogs received CRI of ketamine (GK [n = 6]: bolus 0.5 mg/kg; CRI 20 µg/kg/min in intra- and postoperative periods], fentanyl (GF [n = 5]: bolus 20 µg/kg; intraoperative CRI 5 20 µg/kg/hour and postoperative CRI 2 20 µg/kg/hour), or combination of ketamine-fentanyl (GKF [n = 6]: aforementioned doses) for 8 h. Cardiorespiratory, blood gas analyses, plasma drug concentrations, sedation score (SS), Pain Scores were evaluated. RESULTS: The heart rate decreased in the GF and GKF (p < 0.04); the mean arterial pressure was lower in the GKF than in the GK at 35 min (p < 0.001). Maximum plasma concentrations were observed 5 min after bolus in the GK (2847.06 ± 2903.03 ng/mL) and GKF (2811.20 ± 1931.76 ng/mL). Plasma concentration in intraoperative period of ketamine was of > 100 ng/mL in 5/5 and 2/5 animals in the GKF and GK, respectively; and > 1.1 ng/mL of fentanyl in 4/5 and 3/5 in GKF and GF, respectively. CONCLUSION: Ketamine with/without fentanyl provided analgesia without significant cardiorespiratory and guaranteed the minimal plasma levels with analgesic potential during the 8 h.

Epitheliosis is a histopathological finding associated with malignancy and poor prognosis in dogs with mammary tumors.

Canine mammary epitheliosis (ME) is a poorly studied dysplasia that may have premalignant potential. In this study, the clinicopathological relevance of ME was prospectively studied in 90 female dogs with mammary tumors (MTs) that underwent radical mastectomy. ME distribution, extent, and coexistence with benign and malignant MTs were evaluated for each case (505 mammary glands). ME was macroscopically undetectable and was present in 47/90 (52%) cases, frequently bilateral. In dogs with malignant MTs and ME, diffuse ME throughout the mammary chain was present in 10/39 (26%) cases. A histological ME-carcinoma transition was evident in certain histotypes. By immunohistochemistry (AE1/AE3, cytokeratin 14 [CK-14], CK-8/18, vimentin, calponin, p63, Ki-67, estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2), ME was a slow-growing, triple-negative process with a strong predominance of basal-like nonmyoepithelial cells. ME was associated with older dogs (P = .016), malignant tumors (P = .044), worse clinical stages (P = .013), lymph node metastasis (LNM, P = .021), higher histological grade tumors (P = .035), and shorter overall survival (OS) in univariate analysis (P = .012). Interestingly, ME was distantly located to the malignant tumor in most cases (P = .007). In multivariate analyses, LNM (P = .005), histological grade (P = .006), and tumor size (P = .006) were independent predictors of OS. For the pathologist, the observation of ME should be clearly stated in the MT biopsy report to alert the surgeon/oncologist. Given the differences between canine ME and its human histopathological counterpart (atypical ductal hyperplasia), "epitheliosis" should remain the preferred term for the dog.

Effect of anaesthesia on cell-mediated immunity in dogs undergoing mastectomy for mammary cancer.

OBJECTIVE: To investigate if anaesthesia for canine cancer mastectomy further influences host cell-mediated immunity (CMI) promoting cancer progression. STUDY DESIGN: A randomized, controlled, blinded clinical study. ANIMALS: A total of 20 bitches with malignant mammary tumours of clinical stage II or III undergoing the same type of mastectomy (regional mastectomy). METHODS: Dogs were randomly allocated to one of two anaesthetic groups (10 per group). The anaesthetic protocol of group A used minimally immunosuppressive drugs (tramadol, robenacoxib, propofol), whereas that of group B (control) used more immunosuppressive drugs (morphine, fentanyl, thiopental, isoflurane). For each animal, measurements of white blood cells (WBCs), neutrophils and lymphocytes, and flow cytometric assessment of T cells (CD3+), helper T cells (CD4+), cytotoxic T cells (CD8+) and CD5low+ T cells were performed prior to anaesthesia (day 0) and on days 3 and 10 postsurgery. Data were analysed using a General Linear Model for repeated measures and presented as mean ± standard deviation, p ≤ 0.05. RESULTS: In all animals, on day 3, WBCs and neutrophils were significantly increased (p < 0.0005), while flow cytometry revealed significantly decreased relative percentages of T cells (CD3+) (p = 0.003) and their subpopulations CD4+ (p = 0.006), CD8+ (p = 0.029) and CD5low+ (p = 0.031). Specifically, on day 3, the cytotoxic T cells (CD8+) were significantly decreased (p = 0.05) only in group B, whereas the CD4+ (p = 0.006) and CD5low+ (p = 0.008) T cells in group A. The only significant difference between groups was found preoperatively in the CD4+/CD8+ ratio, which was higher in group A (p = 0.006). CONCLUSIONS AND CLINICAL RELEVANCE: In dogs with mammary cancer undergoing regional mastectomy, a significant decrease in components of CMI was observed on day 3 postsurgery in both anaesthetic groups. Some indication, however, for better preserved cellular immunity by less immunosuppressive anaesthetic/analgesic drugs was detected, rendering their use advisable.

Effect of major versus minor mastectomy on host immunity in canine mammary cancer.

Surgical procedures can affect host immunity proportionally to the extent of surgical trauma. In cancer cases, surgery-induced immunosuppression can potentially promote tumour metastasis. The aim of this study was to investigate, in bitches with malignant mammary tumours, whether major surgery (total unilateral mastectomy or bilateral regional mastectomy) has a more negative effect than minor surgery (unilateral regional mastectomy) on components of host immunity. Twenty bitches with mammary cancer of clinical stage II or III were allocated to group A (minor surgery) or group B (major surgery) of 10 animals each receiving the same anaesthetic protocol for mastectomy. Immune cell measurements in blood [number of leukocytes, neutrophils, lymphocytes and platelets, and relative percentages of T-lymphocytes (CD3+) and their CD4+, CD8+ and CD5low+ subpopulations] were performed before anaesthesia (day 0) and on days 3 and 10 post-mastectomy. On day 3, leukocytes, neutrophils and platelets numbers were higher (p = 0.016, 0.032 and 0.017, respectively) in group B than in group A. For all 20 bitches, T-lymphocytes and the CD4+, CD5low+ T-cells were significantly decreased on day 3, but no significant differences were noted between groups. Minor mastectomy seemed to preserve innate immunity better than major mastectomy, but cellular immunity was rather equally affected.

Fentanyl patch versus tramadol for the control of postoperative pain in canine ovariectomy and mastectomy.

OBJECTIVES: The purpose of the present study was to evaluate the postoperative analgesic efficacy of fentanyl patches versus subcutaneous tramadol after canine ovariectomy, with and without unilateral mastectomy. MATERIALS AND METHODS: A total of 40 female dogs were included in the present study, all of which were domesticated, healthy and 4-12 years of age. The animals were divided into four groups (n = 10 per group) based on the surgery and the analgesic protocol used: the TO group only underwent ovariectomy, and received postoperative tramadol; the TM group underwent both ovariectomy and mastectomy, and received postoperative tramadol; the FO group only underwent ovariectomy, and received fentanyl patches; and the FM group underwent both ovariectomy and mastectomy, and received fentanyl patches. Postoperative pain was evaluated every 4 h for 24 h using a numeric analogue scale (NAS) and a modified Glasgow Composite Measure Pain Scale Short Form (CMPS-SF). RESULTS: The results of the present study showed that patients in all four groups tolerated postoperative surgical stress well. Analysis of variance for repeated measures did not show significant differences in the NAS scores and in Glasgow CMPS-SF between groups in terms of pain scores or rescue analgesia. CLINICAL SIGNIFICANCE: These results indicated that the analgesic effect of the fentanyl patch was similar to that of subcutaneous (SC) tramadol in female dogs after ovariectomy, with and without unilateral mastectomy, suggesting that the fentanyl patch may represent a valid supplementary tool for the control of postoperative pain in animals after surgery.

Epidural administration of combinations of ropivacaine, morphine and xylazine in bitches undergoing total unilateral mastectomy: a randomized clinical trial.

OBJECTIVE: To investigate the epidural administration of combinations of ropivacaine, morphine and xylazine in bitches undergoing unilateral mastectomy. STUDY DESIGN: Prospective, randomized, blinded, clinical study. ANIMALS: A total of 22 bitches scheduled to undergo unilateral mastectomy for mammary tumor excision. METHODS: Dogs were anesthetized with acepromazine (0.02 mg kg-1) and morphine (0.3 mg kg-1) intramuscularly, propofol intravenously (IV) and isoflurane. Prior to the beginning of surgery, dogs were randomly administered one of three epidural treatments: ropivacaine (0.75 mg kg-1) with morphine (0.1 mg kg-1) (group RM, n = 7); ropivacaine with xylazine (0.1 mg kg-1) (group RX, n = 8); or ropivacaine with morphine and xylazine (group RMX, n = 7). Cardiopulmonary variables and the expired concentration of isoflurane (Fe'Iso) were recorded intraoperatively. Meloxicam (0.1 mg kg-1) was administered IV during skin closure. Postoperative pain scores were evaluated with the Glasgow composite measure pain scale short form for 24 hours, and rescue analgesia with morphine (0.5 mg kg-1) was administered intramuscularly when pain scores were ≥ 6/24. RESULTS: Fe'Iso was significantly higher in group RM than in groups RX and RMX. Heart rate decreased significantly in groups RX and RMX, but blood pressure remained within acceptable values. The number of dogs administered rescue analgesia within 24 hours was significantly higher in group RX (seven dogs, 87.5%) than in groups RM (one dog, 14.3%; p = 0.01) and RMX (two dogs, 28.6%; p = 0.04). Time to standing was significantly longer in group RX than in group RM. CONCLUSIONS AND CLINICAL RELEVANCE: All epidural treatments provided adequate antinociception with minimal cardiovascular adverse effects during mastectomy. The inclusion of morphine (groups RM and RMX) provided the best postoperative analgesia. Owing to the undesirable effect of xylazine on ambulation, the combination ropivacaine-morphine appeared to provide greater benefits in bitches undergoing unilateral mastectomy.

A retrospective study and survival analysis on bitches with mammary tumours spayed at the same time of mastectomy.

The aim of the present study was to retrospectively assess whether spaying at the same time of mastectomy increased disease-free survival (DFS) in bitches with mammary tumours and to investigate the utility of clinical data when designing a surgical plan that includes gonadectomy. Characteristics of 225 bitches carrying 489 tumours were retrieved. Of the116 bitches that underwent surgery, 52 bitches underwent mastectomy and ovariectomy, 46 bitches underwent mastectomy alone, whereas 18 bitches were already spayed. Analysis by Kaplan-Meier and in-between groups comparisons using Student's T, Chi-square, and one-way ANOVA tests were performed. DFS was longer for bitches that underwent ovariectomy and mastectomy compared to those that were left intact (p = .00064) or were already spayed (p = .0098). Spaying status affected tumour size (spayed: 2.75 cm ± 2.72; intact: 1.76 cm ± 2.04; p = .039), but not malignancy (p > .05). Differences in age were detected between animals with benign and malignant tumours (years: 9.1 ± 2.8 and 10 ± 2.3; p = .004), with multiple and single tumours (years: 10.18 ± 2.6 and 9.3 ± 2.8; p = .007), and between purebred and mixed breed bitches (years: 10.46 ±1.78 and 9.27 ±2.68; p = .005). Malignant tumours were larger than benign ones (2.17 cm±2.31 and 1.34 cm ±1.82; p = .005) and size increased according to the degree of malignancy. DFS was shorter for animals presenting tumours >2 cm in size (p < .006) and with tumours in the first pair of thoracic mammary glands (p = .00009). Gonadectomy should be suggested to owners of intact bitches carrying mammary tumours and age, size of the tumour, and location should be carefully considered when performing surgery.

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.

Evaluation of post-operative complications after mastectomy performed without perioperative antimicrobial prophylaxis in dogs.

BACKGROUND: Mastectomy is the most common procedure for treatment of mammary tumours. Dogs undergoing mastectomy have a risk of developing surgical site infections (SSI) and other postoperative complications. However, potential risk factors associated with such complications have been sparsely investigated. Thus, the objective of this retrospective study was to determine the incidence of, and identify risk factors for, SSI and non-SSI postoperative complications after mastectomy performed without perioperative antimicrobial prophylaxis in privately owned otherwise clinically healthy dogs. RESULTS: Medical records were reviewed retrospectively for 135 client-owned female dogs, 10-35 kg in weight and three to 10 years of age, which had undergone mastectomy due to mammary tumours at three referral animal hospitals in Sweden over a 3-year period. Twelve (8.9%) dogs developed SSI, and 21 dogs (17.1%) dogs suffered a non-SSI postoperative complication. The incidence of SSI and all complications (SSI and non-SSI) were higher in dogs that had two to three (SSI: P = 0.036 and all complications: P = 0.0039) and four to five (SSI and all complications: P = 0.038) mammary glands excised, compared to dogs that had one mammary gland excised. The incidence of SSI was 1.7% (n = 1/60) in dogs that had one gland removed. The incidence of non-SSI postoperative complications was higher in dogs with a higher body weight (P = 0.02). CONCLUSIONS: The incidence of SSI was lower than or similar to previously reported incidences of SSI in dog populations that have undergone tumour excisional surgery, despite the fact that dogs in the present study had not received perioperative antibiotics. Dogs that had two or more glands excised had an increased risk of developing SSI and non-SSI complications compared to dogs that had one gland excised. Furthermore, higher BW was associated with an increased risk of non-SSI complications. Results from the study indicate that routine use of perioperative antibiotics in tumour excisional surgery can be questioned, at least in single gland mastectomy in otherwise clinically healthy dogs.

Neutrophil-to-lymphocyte ratio is an independent prognostic marker for feline mammary carcinomas.

Blood leukocyte counts and respective derived ratios have been described as potential prognostic markers in several tumours in veterinary oncology. This study aimed to evaluate peripheral blood leukocyte subpopulations and neutrophil-to-lymphocyte ratio (NLR) as prognostic factors for feline mammary carcinomas (FMC). Medical records from cats diagnosed with FMC between 2017 to 2019 were reviewed. Cats were included if fully staged, classified as WHO stage I to III, and submitted to mastectomy. Cats were excluded if they had evidence of other diseases. Forty-nine cats were included. The study endpoints were disease-free interval (DFI) and tumour-specific survival (TSS). The median DFI and TSS were 389 days and 528 days respectively. In the univariate analysis, higher values of total white blood cell count (WBC), neutrophil count (NEU) and NLR were identified as significant prognostic factors for both endpoints (P < .05). On the multivariate analysis, NLR remained an independent prognostic factor for TSS (P = .024). In the receiver operating characteristic curve analysis, the estimated cut-off for WBC was 8.49 × 109 /L (DFI and TSS); for NEU was 4.62 × 109 /L (DFI) and 6.65 × 109 /L (TSS) and for NLR was 2.46. These cut-offs were significant prognostic factors for DFI and TSS (P < .05). NLR cut-off remained an independent prognostic factor for both DFI (P = .032) and TSS (P = .043) in the multivariable analysis. Our results suggest that NLR, NEU, and WBC can be important non-invasive presurgical prognostic markers, and that NLR is an independent prognostic marker for FMC. Prospective studies are warranted to validate its clinical use.

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.

Evaluation of tumescent local anesthesia in cats undergoing unilateral mastectomy.

OBJECTIVE: To evaluate the analgesic efficacy and safety of tumescent local anesthesia (TLA) in cats undergoing unilateral mastectomy. STUDY DESIGN: Prospective clinical trial. ANIMALS: A total of 12 ovariohysterectomized female cats. METHODS: All animals were premedicated with pethidine (4 mg kg-1) intramuscularly (IM), followed by induction of anesthesia with propofol (5 mg kg-1) intravenously and maintenance with isoflurane in oxygen. A refrigerated TLA solution (15 mL kg-1, 8 °C) was injected using a Klein cannula. The solution was composed of 0.5 mL of epinephrine (1 mg mL-1) and 40 mL of 2% lidocaine added to 210 mL lactated Ringer's solution (final lidocaine concentration 0.32%). Heart and respiratory rates, systolic arterial blood pressure, temperature and oxygen saturation were measured during anesthesia. Blood samples were collected from the jugular vein for measurement of plasma lidocaine concentration using high performance liquid chromatography. Postoperative pain scores were evaluated hourly for 6 hours. Analgesic rescue was performed with tramadol (2 mg kg-1) IM and meloxicam (0.15 mg kg-1) subcutaneously. RESULTS: Plasma lidocaine concentration peaked at 90 minutes after injection of TLA, but no concentration considered toxic for the species was measured. The median postoperative analgesia time was 6 hours after injection of TLA. CONCLUSIONS: This study found that TLA prevented sympathetic response to noxious stimuli during anesthesia and provided satisfactory postoperative analgesia in cats submitted to total unilateral mastectomy, with no apparent signs of toxicity. CLINICAL RELEVANCE: TLA can prevent sympathetic stimulation resulting from noxious stimuli during anesthesia, promoting good intraoperative conditions, proving to be a viable addition to analgesia in cats submitted to a total unilateral mastectomy.