use strict;
my $str = 'The quick brown fox jumps over the lazy dog
The dog was lazy
The dog dog dog
The dog dog
The dog';
my $regex = qr/\bdog[^\w\n]+\b/mip;
my $subst = '';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html