In these extracts the word abuse is used in the sense of ‘an individual piece of invective’ or ‘an abusive comment’ and is clearly a countable noun.

He came to the stake in a fair black gown furred and faced with foins.

It were when my father were employed as mason under 'brick and mortar Benson,' as they called him, for repairs of a wall, and they were short of stones, and they chipped up the figure I be telling you of.

John McClane: Sorry Hans, wrong guess. Would you like to go for Double Jeopardy where the scores can really change?