Any veterinarian may dispose of any animal abandoned in his establishment, provided he shall give notice of his intention to do so to the owner at his last-known address by registered or certified mail, return receipt requested, and shall allow a period of fifteen days to elapse after the receipt is returned before disposing of such animal; but, if the owner cannot be located at such address, the veterinarian shall give such notice by publication in a newspaper having a circulation in the town in which such owner was last known to reside, and shall allow a period of fifteen days to elapse after such publication before disposing of such animal.