Kittle cattle is a somewhat archaic Scottish and British expression meaning capricious, touchy, unpredictable, and just plain difficult to manage.
Kittle, in this case, comes from the Middle English meaning 'tickle', although in this case it may be that the cattle are not so much ticklish as skittish. Cattle does indeed refer to cattle... but this phrase is rarely if ever used literally; womenfolk, workers, children, and especially authors, are kittle cattle.
There is, indeed, a very small literary tradition of using kittle cattle to refer to authors, in part because most people who use it are writers, and find it amusing to refer to themselves as such. However, this usage was probably influenced by the first usage of kittle cattle in print, which appears to be in Lucy Maud Montgomery's Anne of the Island, published in 1915: "Authors are kittle cattle. You never know when or how they will break out." (Pris, Anne of the Island, Chapter XXXVI, The Gardners' Call).
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