In order to avoid misunderstandings about euthanasia and to have documentation that the owner of the pet has given permission to the attending veterinarian or registered veterinary technician it is typical for an authorization to be signed by the owner of the pet.
Because there have been instances of wild animals dying as a result of barbiturate toxicosis after consuming remains of a pet euthanized with sodium pentobarbitol in cases of home burial there is an assignment of the client the responsibility of burial in a manner which will preclude remains consumption by any other animal. There have been cases in which the U.S, Fish and Wildlife Service have prosecuted negligent parties.
Historically observation of a potentially rabid animal for 10 days after they have bitten has been a very helpful diagnostic tool. This is because an animal that is infected with rabies nearly always shows clinical signs of the disease in the 10 day period after infection. Euthanasia eliminates the potential use of this tool. Rabies causes excruciating suffering coupled with a hopeless death sentence. It is for this reason that public health officials have enacted protocols requiring discovery of bites on euthanasia authorization. The document that Paws at Peace requires can be found here for clients wishing to review it.