my @cats = qw(persian siamese cute);
my @dogs = qw(doverman bulldog);

## Bad data structure
my @data = (\@cats, \@dogs);

function( \@data );

## Good data structure
function1({
  cats => \@cats,
  dogs => \@dogs,
});

##</code><code>##

sub function1 {
    my $params = shift;

    warn "My Dogs\n";
    for (@{$params->{'dogs'}}) { warn "\t$_\n" }

    warn "My Cats\n";
    for (@{$params->{'cats'}}) { warn "\t$_\n" }
}