Cliff Sims was a conservative media figure in Alabama before packing his bags and joining Donald Trump’s presidential campaign a few years ago. He cultivated close ties to the New York Republican, and after the election, Sims went to the White House, where he worked as “director of message strategy,” and where he apparently spent a fair amount of time with the president.

He reflects on his experiences in a new book, “Team of Vipers,” which the Washington Post reported on yesterday. There’s quite a bit to chew on, but I was struck by an anecdote about Trump’s angry reaction when then-House Speaker Paul Ryan (R-Wis.) criticized the president’s comments about a deadly white supremacist rally in Charlottesville.

“Paul, do you know why Democrats have been kicking your a– for decades? Because they know a little word called ‘loyalty,’ ” Trump told Ryan, then a Wisconsin congressman. “Why do you think Nancy [Pelosi] has held on this long? Have you seen her? She’s a disaster. Every time she opens her mouth another Republican gets elected. But they stick with her…. Why can’t you be loyal to your president, Paul?” The tormenting continued. Trump recalled Ryan distancing himself from Trump in October 2016, in the days after the “Access Hollywood” video in which he bragged of fondling women first surfaced in The Washington Post. “I remember being in Wisconsin and your own people were booing you,” Trump told him, according to former West Wing communications aide Cliff Sims. “You were out there dying like a dog, Paul. Like a dog! And what’d I do? I saved your a–.”

If Sims’ anecdote is accurate, it’s interesting for a variety of reasons, including the president’s unhealthy ideas about how “loyalty” is supposed to work.

But I’m also curious about Trump telling Ryan he was “dying like a dog” in 2016. What is it about Trump and dog metaphors?

I started poking around his Twitter archive and was amazed at the frequency of his canine references. Retired Gen. Stanley McChrystal was “fired like a dog.” According to Trump, so were conservative media figures Erick Erickson and Glenn Beck.

Egypt’s Hosni Mubarak was “dropped like a dog.” Steve Bannon was “dumped like a dog.” Mitt Romney “choked like a dog.” Ted Cruz “lies like a dog.” Brent Bozell allegedly went to Trump’s office “begging for money like a dog.”

“Robert Pattinson should not take back Kristen Stewart,” the future president wrote in 2012. “She cheated on him like a dog.”

Asked why he went after Arianna Huffington’s appearance, Trump wrote, just two months before launching his presidential campaign, “Because she is a dog who wrongfully comments on me.”

After Omarosa Manigault-Newman left the White House, Trump called her “a crazed, crying lowlife,” before adding, “Good work by General Kelly for quickly firing that dog!”

And now, according to Cliff Sims’ book, we learn that the president reportedly told Paul Ryan, “You were out there dying like a dog, Paul. Like a dog!”

Maybe someone can get this guy a book of idiomatic expressions. He clearly needs a new favorite metaphor.