The owner or keeper of every dog in his custody shall at all
times, between the hours of sunset and sunrise of each day, keep such
dog confined within an enclosure from which it cannot escape. Such
enclosure shall be of a size conducive to good sanitary practices.
If an enclosure cannot be provided by the owner or keeper, each dog
must be firmly secured by means of a collar and chain or other device
so that it cannot stray beyond the premises on which it is secured.