Michigan

MCL § 750.50

(1) As used in this section and section 50b:1

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(n) “Tethering” means the restraint and confinement of a dog by use of a chain, rope, or similar device.(2) An owner, possessor, or person having the charge or custody of an animal shall not do any of the following:
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(g) Tether a dog unless the tether is at least 3 times the length of the dog as measured from the tip of its nose to the base of its tail and is attached to a harness or nonchoke collar designed for tethering.

This subdivision does not apply if the tethering of the dog occurs while the dog is being groomed, trained, transported, or used in a hunt or event where a shorter tether is necessary for the safety and well-being of the dog and others.