Treatment options for dogs with metastatic (stage III) splenic hemangiosarcoma are limited. A doxorubicin-based chemotherapy regimen is commonly administered; however, there are no published data to support this practice. The aim of this study was to investigate the impact of maximum-tolerated-dose chemotherapy (MTD), metronomic chemotherapy (MC) and no adjuvant treatment on outcome in dogs with stage III splenic hemangiosarcoma undergoing splenectomy. Medical records of dogs with stage III splenic hemangiosarcoma that underwent splenectomy followed by MTD chemotherapy, MC or no adjuvant treatment were retrieved. Time to progression (TTP), survival time (ST) and toxicity were evaluated. One hundred three dogs were identified: 23 received adjuvant MTD, 38 MC and 42 were not medically treated.Overall median TTP and ST were 50 (95% confidence interval [CI], 39-61) and 55 days (95% CI, 43-66), respectively. Dogs treated with adjuvant MTD had a significantly longer TTP and ST compared with dogs receiving MC (median TTP, 134 vs 52 days, P = .025; median ST, 140 vs 58 days, P = .023, respectively). Dogs treated by splenectomy only had the shortest median TTP (28 days) and ST (40 days). However, treatment-related adverse events (AEs) were significantly more frequent in the MTD group (P = .017). The outcome for dogs with metastatic splenic hemangiosarcoma is poor. While MTD showed greater efficacy compared to MC, toxicity was higher in this group. Treatment-related AEs need to be carefully balanced against this modest survival prolongation when offering adjuvant MTD to dogs with advanced stage hemangiosarcoma. K E Y W O R D S dog, hemangiosarcoma, maximum tolerated chemotherapy, metastasis, metronomic chemotherapy, prognosis

In dogs, digit squamous cell carcinoma (SCC) is uncommon. Clinical signs are frequently underestimated, leading to a diagnostic delay. The purpose of this retrospective study was to report our experience regarding the clinical presentation, diagnostic work-up, treatment and outcome of 79 client-owned dogs with SCC of the digit. The greatest majority (84.8%) of dogs was dark-coated. Schnauzers represented approximately one third of the study population, and had a poorer outcome compared with other breeds. The majority of SCCs occurred in the front limbs (61%), and bone lysis was frequently observed (92.4%). Approximately 9% of dogs had involvement of multiple digits, and this was associated with a shorter time to progression (TTP; P = 0.047). Similarly, a duration of clinical signs >90 days was associated with a shorter TTP (P = 0.02). Regional lymph node metastases were documented in 17.7% of dogs at admission and were significantly associated with tumor-related death (P < 0.001). At presentation, none of the dogs had evidence of distant metastasis. Digit amputation achieved adequate local tumor control in the majority of cases. Adjuvant chemotherapy and radiation therapy were carried out in 21.5% of cases, with uncertain benefit. Due to the relatively non-aggressive clinical behavior of digit SCC, chemotherapy should only be offered in the case of metastatic disease. Approximately one fourth of dogs developed de novo SCCs during the follow-up. Careful examination of the digits should be encouraged in breeds considered at high risk and in dogs with a previous history of digital SCC.

Introduction Historically, the prognosis for dogs with stage II Kiupel high‐grade cutaneous mast cell tumours has been considered poor. Objectives The aim of this study was to explore the impact of lymphadenectomy on outcome in dogs with Kiupel high‐grade cutaneous mast cell tumours and overt regional lymph node metastasis. Material and Methods Data from dogs with completely staged Kiupel high‐grade cutaneous mast cell tumours with overt and/or certain regional lymph node metastasis undergoing excision of the primary tumours and adjuvant medical treatment were extracted. Dogs with a cytological diagnosis of regional lymph node metastasis that did not undergo lymphadenectomy were compared with dogs that underwent lymphadenectomy and had a histological diagnosis of overt lymph node metastasis. Results Forty‐nine dogs were included, 18 did not undergo lymphadenectomy while 31 underwent lymphadenectomy. Median time to progression was significantly shorter in dogs that did not undergo lymphadenectomy (150 days, 95% confidence interval: 129 to 170) compared to the other dogs (229 days, 95% confidence interval: 191 to 266). Median survival time was also shorter in dogs that did not undergo lymphadenectomy (250 days, 95% confidence interval: 191 to 308) compared to dogs that underwent lymphadenectomy (371 days, 95% confidence interval: 311 to 430). On multivariable analysis, lack of lymphadenectomy was associated with higher risk of overall tumour progression (hazard ratio: 2.05, 95% confidence interval: 1.02 to 4.13), nodal progression (hazard ratio: 3.4, 95% confidence interval: 1.65 to 7.02) and tumour‐related death (hazard ratio 3.63, 95% confidence interval: 1.72 to 7.66), whereas tumour size was associated with higher risk of local recurrence (hazard ratio: 3.61, 95% confidence interval: 1.06 to 13). Clinical significance Regional lymphadenectomy may improve outcome in dogs with biologically aggressive cutaneous mast cell tumours.

Background: Risk factors for oral squamous cell carcinoma (OSCC) in cats are derived from a single study dated almost 20 years ago. The relationship between inflammation of oral tissues and OSCC is still unclear. Objectives: To investigate previously proposed and novel potential risk factors for OSCC development, including oral inflammatory diseases. Animals: Hundred cats with OSCC, 70 cats with chronic gingivostomatitis (CGS), 63 cats with periodontal disease (PD), and 500 controls. Methods: Prospective, observational case-control study. Cats with OSCC were compared with an age-matched control sample of client-owned cats and cats with CGS or PD. Owners of cats completed an anonymous questionnaire including demographic, environmental and lifestyle information.Results: On multivariable logistic regression, covariates significantly associated with an increased risk of OSCC were rural environment (OR: 1.77; 95%

In canine cutaneous mast cell tumours (cMCTs), histologic grade and clinical stage are the most important prognostic factors, with high‐grade tumours and metastatic lymph nodes (LNs) significantly influencing the evolution of disease. However, it is uncertain whether histologic grade and clinical stage should be given equal weighting value in patient prognostication and management. Dogs with low‐ and high‐grade cMCTs and at least one overtly metastatic sentinel LN undergoing standardized treatment, consisting of surgical excision of the cMCT, lymphadenectomy and chemotherapy, were retrospectively included. The aim was to determine whether, at the same clinical stage, histologic grade retained prognostic relevance. Sixty dogs were included: 26 had a high‐grade cMCT tumour and 34 had a low‐grade cMCT. Median follow‐up was 367 days (range, 187–748) in the high‐grade group, and 1208 days (range, 180–2576) in the low‐grade group. Median time to progression was significantly shorter in the high‐grade group than in the low‐grade group (214 days versus not reached; p < .001), as well as tumour‐specific survival (545 days versus not reached; p < .001). On multivariable analysis, a high histologic grade and incomplete margins retained prognostic significance for both tumour progression and tumour‐specific death. In dogs with cMCT and at least one overtly metastatic LN undergoing multimodal treatment, histologic grade significantly correlated with outcome. Overall prognosis was not unfavourable, even in the high‐grade group, further supporting that a multimodal therapeutic approach, addressing primary tumour and sentinel LN, should be offered. Whether chemotherapy should be incorporated in the therapeutic planning of low‐grade cMCTs remains to be defined.

Most dogs with large B‐cell lymphoma (LBCL) that undergo chemotherapy and achieve clinical complete remission (CR) eventually relapse. However, time to relapse (TTR) is unpredictable. The aims of this prospective study were to assess the influence of post‐chemotherapy lymph node (LN) infiltration by large CD21+ cells using flow cytometry (FC) on TTR, and to establish a cut‐off value of prognostic significance. Dogs with newly‐diagnosed, completely staged LBCL in CR after treatment were enrolled. Minimal residual disease (MRD) analysis by FC was performed on LN aspirates. TTR was calculated between MRD and relapse. Thirty‐one dogs were enrolled: 4% had stage V disease, and diffuse large B‐cell lymphoma was the most common histotype (74%). Based on LN infiltration at MRD evaluation, three groups were created: (a) acellular samples, (b) ≤0.5% infiltration and (c) >0.5% infiltration. Overall median TTR was 154 days (range, 31‐1974): 22 (71%) dogs relapsed during the study period, whereas 9 (29%) dogs did not. The difference among the three groups was significant (P = 0.042 log‐rank test): median TTR was not reached for dogs with LN infiltration ≤0.5% (range, 195‐429 days), 164 days (range 63‐1974) for dogs with acellular LN samples, and 118 days (range, 31‐232) for dogs with LN infiltration >0.5%. These results demonstrate that MRD assessment by FC on LN aspirates in dogs with LBCL in clinical CR predicts TTR. LN infiltration by >0.5% large CD21+ cells after treatment is an unfavourable prognostic factor.

A 4-year-old 4.7-kg (10.4-lb) intact female domestic short-haired cat with a history of left forelimb amputation due to periarticular histiocytic sarcoma (HS) was referred to the Oncology Unit at the University of Bologna. Seven months prior to referral, the cat had been evaluated by the referring veterinarian for a 1-month history of a Grade 3 left forelimb lameness. Initially, the cat had been treated with oral meloxicam (Metacam, Boehringer Ingelheim Pharma, Ingelheim am Rhein, Germany) at 0.05 mg/kg (0.02 mg/lb) q 24 h for 1 week with exercise restriction. Despite initial clinical improvement, lameness recurred, and a mild soft tissue swelling of the left distal radioulnar joint developed within a few weeks. Regrettably, the travel restrictions due to the Coronavirus pandemic delayed the consultation with an oncologist. The cat was re-evaluated by the referring veterinarian only 5 months after the first presentation. At that time, initial diagnostic tests included a left forelimb radiograph (latero-medial view), three-view thoracic radiographs, abdominal ultrasound, and routine blood analysis (complete blood count, serum biochemistry, and clotting profile). Forelimb radiography revealed severe permeative lysis of the carpal bones extending across the joint space to the distal radial and ulnar epiphyses and diaphyses, as well as to the first metacarpal bone. Destruction of both medullary and cortical bone was evidenced at these sites with an ill-defined transition zone, along with moderate adjacent soft tissue swelling.The rest of the diagnostic procedures were unremarkable. Due to suspected neoplastic disease, a core biopsy of the bone lesion was submitted for histopathologic evaluation. Microscopic examination

Timely delivery of adjuvant chemotherapy has been shown to be advantageous in many human cancers and canine osteosarcoma. Adjuvant chemotherapy has been shown to improve outcome for canine splenic hemangiosarcoma. The aim of this retrospective study was to investigate whether timely adjuvant chemotherapy administration resulted in better outcome in dogs with non-metastatic splenic hemangiosarcoma undergoing splenectomy. Medical records were searched for dogs with non-metastatic, splenic hemangiosarcoma that received splenectomy and adjuvant chemotherapy. The number of days from surgery to the first chemotherapy dose (StoC) was evaluated to identify the cut-off value associated with the best survival advantage. StoC and other possible prognostic factors were tested for influence on time to metastasis (TTM) and overall survival (OS). Seventy dogs were included.Median StoC was 20 days (range: 4-70). The time interval associated with the greatest survival benefit was 21 days. Median TTM and OS of dogs with StoC ≤ 21 days were significantly longer than those with StoC >21 days (TTM: 163 vs. 118 days, p = .001; OS: 238 vs. 146 days, p < .001). On multivariable analysis, StoC >21 days was the only variable significantly associated with increased risk of tumour progression (HR 2.1, p = .010) and death (HR 2.3; p = .008). Starting adjuvant chemotherapy within 21 days of surgery may be associated with a survival benefit in dogs with nonmetastatic splenic hemangiosarcoma, possibly due to the early targeting of newly recruited metastatic cells after surgery.