curtail dog

from the GNU version of the Collaborative International Dictionary of English.

• A dog with a docked tail; formerly, the dog of a person not qualified to course, which, by the forest laws, must have its tail cut short, partly as a mark, and partly from a notion that the tail is necessary to a dog in running; hence, a dog not fit for sporting.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun obsolete A dog with a docked tail; formerly, the dog of a person not qualified to course, which, by the forest laws, must have its tail cut short, partly as a mark, and partly from a notion that the tail is necessary to a dog in running.
• noun obsolete, by extension A dog not fit for sporting.