The dog disliked our newborn but I wanted to keep both. Was there any hope?

The ultimatum came within days of us arriving home with our daughter in April: Train the dog to chill out and relax around our newborn, or he’s got to go — no ifs, ands, or buts, my fiancee proclaimed.

“He’s out,” she said.

Although I’ve never doubted her love for Rio, a 5-year-old Blue Heeler-Shepherd mix we saved from a kill shelter in Arkansas several years ago, her stance was clear.

As I lovingly stared down into my first child’s dark-brown eyes (I’m talking about the dog), I contemplated our dilemma. This was going to be a lot of work.

Rio’s hackles would spring up like a Whack-a-mole every time the baby cooed, and hushing the baby’s cries and stopping Rio’s barking while simultaneously changing a diaper at 3 a.m. was tantamount to being on some sadistic TV game show. Could we really change his attitude and keep our sanity?

That thought was quickly supplanted by the next one: “I wonder what I should pack for our new life on the road together,” I asked Rio.

In the end, however, no suitcases needed preparing, and no child was left behind. As we soon found out, after a bit of preliminary Internet sleuthing, this was a problem that a lot of new parents have faced. We also learned that our approach of waiting to call in a trainer only after the baby arrived home was the wrong one entirely.

Experts in the field of behavioral dog training say that expectant parents who, up until birth, have been lathering their dog with bedtime snuggles, endless ear scratches, and treats galore should avoid the grave mistake we made, and instead prepare their pet for the drastic change of environment far in advance.

“The minute you start preparing yourself to have a child, you should start preparing your dog,” said Jenifer Vickery, owner of The Pawsitive Dog and a trainer for more than two decades. “You don’t want to run into a challenge and be forced to be reactive. In an ideal world, we want to encourage people to be proactive, so you can venture into this amazing endeavor confidently and comfortably.”

To get the right structure in place for a pet, Vickery recommends families speak with a qualified dog trainer and reach out to other parents who have dogs and have gone through the process. Doing this, she said, helps people understand some of the challenges that may lay ahead.

Common hurdles can include getting a dog used to baby toys and devices, the sound of crying, and receiving less attention.

“The earlier we get started practicing these things, the sooner we can expose any potential holes that need to be addressed,” she said. “Quite a bit of time and heartache and headaches can be saved by preparing from the get-go.”

Jackie O’Neil, owner of Colonial Dog Training, a company that specializes in a program called Cribs and Canines, offered similar advice: If you know the baby is coming, it’s beneficial to create and maintain consistent guidelines for the dog, both before and after the new baby’s arrival, her website says.

“Even when a dog is quote-unquote good, a baby coming into the house is a life-changing experience and therefore can cause the dog stress and anxiety,” said O’Neil, who does in-house training. “Show the dog the rules of the home and get that dog into a structured lifestyle.”

This helps ease the transition, she said.

Of course, there’s always the people like us — the ones who let “how-to” guides for dog owners and new parents stack up with the other books they’ve panic-purchased on Amazon but never actually read; the ones who walk through the door with a newborn, their fingers crossed that everything will just work itself out.

It didn’t. And at one point it got so stressful, we had to leave the dog with family members, an option many new parents might not have.

Thankfully, despite our serious lack of preparation, all hope was not lost.

Determined to make a change, we turned to friends who were expecting a child a few months after ours was born, and who had heeded the advice to be proactive.

We emergency-texted the trainer they had been using, Kate Brady, and all but begged her to rescue us.

Brady showed up at our house and immediately recognized that Rio was of the mindset that he was head of the household. We had spoiled him. He had no direction. Dogs need leadership, she said, and feel much more comfortable when they have it.

“When a new baby comes into a home, the dog needs to feel secure and needs to know that there are rules,” said Brady, who volunteers with several local dog organizations. “If you start providing them — however late you start — the dog will pick up on that and be much happier, especially in a situation where there is something new like this.”

After an intense few weeks of training, Rio grew accustomed to the changes. He learned to stay out of any room the baby was in, unless we gave him permission to enter; started to go to his “place” — a small bed in the dining room — on command; and even stopped the barking and grumbling, a little at a time.

These days, we have a different problem, but it’s one that we’ve started to consider a luxury in comparison: Rio seems to be in love with the baby.

Whenever we lay her down for “tummy time,” he’ll snuggle up next to her playmat, as if cheering her on. When the baby cries at night to be changed, Rio gets up with us, follows us into the nursery, and stands guard.

Although I think it’s adorable — everything Rio does is adorable — Vickery, of The Pawsitive Dog, reminded me that the hard work should continue as the baby grows. More importantly, we shouldn’t let down our guard.

“The easiest part is bringing the baby home,” she said. “It becomes more challenging when you have a crawling baby or a toddler chasing the dog.”