while (<DATA>) {
	# match the first word
	# in lines that don't contain "vet" anywhere
    push(@array, $1) if m/^(?!\w+\b.*vet)(\w+)/i;
}

print("@array\n");

__DATA__
David    Veterinarian
Jackie  Orthopedist
Karen Veterinarian
Vetch   Orthopedist
Vetch   Veterinarian