A possible role of coarse fractionated radiotherapy in the management of gingival squamous cell carcinoma in dogs: A retrospective study of 21 cases from two referral centers in the UK

Surgery with or without the addition of radiotherapy is the treatment of choice for canine oral squamous cell carcinoma (SCC). Fractionated radiotherapy alone is also effective in the long-term control of the disease, however coarse fractionated radiotherapy (CF-RT) for gingival SCC has not been extensively reported. The aim of this study was to describe side effects, clinical response, and median survival time (MST) of dogs with gingival SCC treated with CF-RT in the palliative and adjuvant setting. Twenty-one cases from two referral centres in the UK treated with CF-RT for gingival SCC between July 2013 and June 2019 were retrospectively evaluated. Of the 21 dogs, 11 developed mild acute adverse effects. Oral mucositis was the most common radiation induced toxicity. Three dogs developed chronic severe adverse effects (oro-nasal fistula, bone necrosis and gum recession). Overall clinical response rate was 77% in dogs receiving palliative treatment with MST of 365 days (60–1,095 days). MST was not reached for dogs treated in the adjuvant setting with a mean of 466 days (121–730 days). In cases of advanced gross disease CF-RT might have a role in short term palliation of clinical signs. However, it carries a significant risk of late toxicity for cases with unexpectedly long survival times and further investigations are required to identify an optimal CF-RT protocol. Randomized controlled trials are needed to confirm the role of CF-RT as adjuvant treatment of incompletely resected gingival SCC.     

Contribution of white clover varieties to total sward production under typical farm management

White clover varieties, potentially suitable for inclusion in seed mixtures for mixed stock-rearing farm systems, were evaluated when growing with S23 perennial ryegrass under rotational sheep grazing with a silage cut in late May or early June, as practiced on farms. Monoculture grass swards were also included to enable the direct and indirect contribution of white clover to total sward production to be evaluated.
White clover increased total sward production during all three years of the trial by an average of 50%. Although clover content of swards were similar, large differences occurred in their grass content, especially in the third year, when difference in total yields of swards based on large–leaved clover varieties was 2 t ha ⁻¹ while difference in clover yield was only 0-6 to ha^–1 The indirect contribution of white clover, namely the extra grass resulting from N transfer, was greater in the spring than in the autumn. It was also greater for Nesta than for other varieties. and exceptional for this variety in that the increase in grass yield above that of grass monoculture was maintained over three harvest years.