Easy drive. You should seriously consider taking longer than you plan so you can see some of the great sights along the way.
Head north toward Lazaro Cardenes and take the toll road heading inland. If you stay on it, you will buy pass everything including Morelia. Remember that all tolls are cash and only pesos.
Get to Hwy 15D also a toll road and head north. Watch for the bypass for Guadalajara, it is a lifesaver. All of these bypasses will be shown on online maps.
We drove down 4 years ago and stopped for just two nights also. Tepic is a great city to stop at, if you do, don't take the bypass. The main road circles around town and isn't bad.
Hotels are easy with the dogs, we were traveling with two large dogs and a cat. You want a nice "no tell motel." These are fairly easy to spot, they are NICE, and have both an entrance and an exit drive. Garages have nice doors or curtains. They don't care if you bring in farm animals as long as the room is in good condition when you leave. The parking is very secure, the ones we have used are very clean and often have interesting extras, like a sex chair, porno flicks, a sex toy menu to name a few. They also often have food delivery services. They will quote you a rate for a few hours usually, but will give you a price for more. We hit the road at 6am each day, and as we were walking out the door the phone rang to remind us it was time. We highly recommend them. They are often found on the edges of towns. In Tepic we made the mistake of not asking for AC and wish we had.
Back on Hwy 15D head north, always taking the bypasses around towns. There will be gas stations along the way, all taking credit cards, misc restaurants and snacks in the stations. We loaded an ice chest so that all we really needed was ice and liquids. There are always places to pee the dogs at toll booths, and ususally restrooms. All toll roads have the letter D.
We spent our second night in Navajoa at a spectacular "no tell motel." It had a large planter in the open roof garage area so all we had to do is clean up after the dogs in the morning and all was well. It was a great break for the three of them.
Stay on the toll roads until Santa Ana where you take the turn toward Sonoyta. Most of that route is also toll road and the desert scenery is fabulous.
When you get near the border you will see where visitors turn in their vehicle permits. Hopefully someone will jump in and say exactly where that is now, it moves. Take in your residency cards and passport and they will stamp you out. Make sure they stamp you for exit, not enter. Repeat the same on the way back.
It would be easy to just blow it off and exit and reenter without doing this, but if someone decided to check you, you'll have a problem.
All the dogs need is a rabies certificate, and only if they ask for it. Check out the stickies above, especially the Border Crossing Tips.
Sonoyta is a very quiet border crossing except on Sunday's when the world leaves Puerto Penasco and heads back to the US. Otherwise, you can expect to just drive up to the border and be in the US in a couple of minutes.
Watch your speeds on the roads, there will be speed traps all along the way.
We made a point of changing drivers about every 3 hours and getting out and stretching ourselves and the dogs. We were glad we did because we made it through easily. We know we could have done longer stints, but that made it easy.
Reentering with the dogs is incredibly easy. The health certificates the airlines require is simply their policy. All you need legally is the rabies. When you do return to Mexico, all you need to do is to get your passport restamped entry, let them look at your residency card, and you are on your way. With Guerrero plates, no one will look at your vehicle or even you. If you didn't legally have to stop and check in and out of country you wouldn't even have to slow down upon entry.
We spent 2 months in California four years ago. We never were stopped with our Guerrero plated vehicle and entering the US was simply handing them our passports, having them scanned and being sent on our way. Amazing. Even more amazing was that our Qualitas insurance covered us in the US!
I'm sure that others will have more great information to add.
