We are nearly 151 days into the Trump presidency, and many government positions remain unfilled. So does a crucial White House job: first pet.Although Melania Trump and 11-year-old Barron have moved in with him, the nation’s 45th president remains the first pet-less U.S. leader in 150 years. This is, as we have noted, a lost opportunity for bipartisan appeal and good press.Fortunately, Vice President Mike Pence’s swelling menagerie is there to fill the presidential pet void.