Here are some tips for traveling with pets in RVs ... http://www.doityourselfrv.com/travel-pets-rv-easy-ways-fun-rving-favorite-friend/
When we traveled to the U.S. south-west this fall, we were surprised at the number of people traveling with dogs. Since most of the travelers were without children (due to school), this probably skewed the number of dogs somewhat as a lot of people who don't have children with them will have dogs as a substitute. We see this a lot with our senior friends.
The dogs would affect their activities, however, because some people cannot leave their dogs alone for long for various reasons. One couple I talked to in Flagstaff was unable to take the jeep tour in Sedona as they had dogs they could not leave. We would have been unable to see Antelope Canyon if we had this restriction. Everyone has to make tp make their own choices as to what is more important.
One couple we know has two small dogs and they have them trained to use piddle pads in the RV. The dogs are o.k. alone, and this way they can at least "go" if they need to.
With a cat, we have no worries as she just sleeps while we are away. You usually don't see cats very much as not many people walk them on a leash like we do.