This also, of course, implicates "common sense" in terms of the actual manner in which this expense would be deducted.
The only form to claim the deduction is on Schedule C (assuming this is a sole proprietorship) and the only line on that schedule for the deduction would be 27a (Other expenses). Unfortunately, that line requires a description of the expense in Part V and "Guard dog training" with an amount in the neighborhood of $3,000 would almost certainly raise a red flag.
