You would think that a goat would avoid this plant. It's mildly toxic. The leaves are strongly scented. It just doesn't seem to be a thing that animals would want to eat. Wrong. Both my goats and sheep will, and have, eaten entire plants right down to the thick stems. They prefer the young growing tips, but will repeatedly return to the plant until there is almost nothing left.
Conclusion? Keep the goat away from the garden.