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 While lymphadenectomy of metastatic lymph nodes (LNs) has been associated with improved outcome, the clinical utility of prophylactic lymphadenectomy in dogs with stage I cutaneous mast cell tumors (cMCTs) remains a controversial topic. To assess the therapeutic role of lymphadenectomy of uninvolved regional LNs, the long-term outcome of cMCT-bearing dogs with cytologically negative and surgically unresected regional LNs (observation only, OO) was compared with that of dogs with surgically resected and histologically negative regional LNs (prophylactic regional lymphadenectomy, PRL). Results A retrospective analysis of 64 dogs with a low-grade, completely resected stage I cMCT was performed: 35 (54.7%) dogs were subjected to OO and 29 (45.3%) underwent PRL. Dogs were monitored for a median of 813 and 763 days in the OO group and PRL group, respectively. The number of dogs undergoing MCT progression was significantly higher in the OO group (P = 0.028) and curve comparison revealed a tendency to a better time to progression in the PRL group (P = 0.058). No significant difference in survival time (P = 0.294) was observed between dogs in the OO and PRL groups. Conclusions Our results showed that lack of immediate lymphadenectomy was associated with a higher risk for tumor progression. This preliminary judgement, reinforced by the findings that lymphadenectomy was well tolerated in all cases, and that histopathology provides the definitive assessment of the nodal pathological status, may suggest that prophylactic lymphadenectomy is indicated in the management of stage I MCTs. Larger prospective studies are warranted for generating clinical evidence of this latter hypothesis.

Objective To evaluate the performance and define cut‐offs for the interpretation of a thyroid‐stimulating hormone (TSH) stimulation test with a recombinant human TSH dose of 75 μg/dog administered intravenously in dogs with suspected hypothyroidism. Materials and Methods Cross‐sectional study. Medical records of dogs presented for suspected hypothyroidism were retrospectively reviewed. Animals were included if a TSH stimulation test with a recombinant human TSH dose of 75 μg/dog was performed and follow‐up was available. Dogs with a post‐TSH serum total thyroxine (T4) level of ≥2.2 μg/dL were considered euthyroid. Dogs with a post‐TSH T4 level of <2.2 μg/dL were classified as hypothyroid or euthyroid based on follow‐up, including response to levothyroxine supplementation. A receiver operating characteristic curve analysis was used to define the performance of the test. Results One hundred and fourteen dogs were included. Forty were classified as hypothyroid and 74 as euthyroid. Post‐TSH T4 cut‐offs of 1.3 and 1.7 μg/dL showed sensitivities of 92.5 and 100% and specificities of 97.3 and 93.2%, respectively. Post‐TSH T4 levels of >1.7 μg/dL had a negative predictive value of 100%. Post‐TSH T4 levels of <1.3 μg/dL showed a positive predictive value of 94.9%. Area under the ROC curve for post‐TSH T4 was 0.99. Clinical Significance A TSH stimulation test performed with a recombinant human TSH dose of 75 μg/dog is highly reliable to discriminate between hypothyroid and euthyroid dogs, even in cases of concurrent non‐thyroidal illness or administration of medications. A post‐stimulation T4 concentration of >1.7 μg/dL is suggestive of normal thyroid function.

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.