One of our informants encountered a story, related by one Thomas Bloomer Balch, a Presbyterian minister writing about a visit to Monticello ca. 1839, and remembering his childhood in the D.C. area (published in "Picturesque Narratives. South West Range," The Christian World vol. 3 (August 1843)). Reverend Balch remembers that during Mr. Jefferson's presidency, a little boy wandered onto the grounds of the President's House and was killed by TJ's "ill-tempered goat." (Balch also claimed that the premises were "overrun with Arabian horses, cashmere goats and Peruvian llamas sent to TJ by foreign potentates." I believe these are our informant's words, not Mr. Balch's...)
We thought this was an interesting but apocryphal TJ story, until we happened to mention it to another coworker at our semi-weekly coffee, who responded, "Oh yeah, that's true." Imagine our astonishment. I almost dropped my doughnut. Research Historian Cinder Stanton related this story in Part II of her lecture, "Thomas Jefferson and Sheep," available in streaming audio on our website at http://www.monticello.org/streaming/speakers/stanton.html. (Apparently it was a ram, not a goat.) And if you are still thirsting for more information on Jefferson and his ill-tempered sheep, see Cinder's Keepsake article, "Sheep for the President."