It's okay to look at your mobile phone for a moment. But
- Put your dog on a leash
- Stand still until you have finished reading. If you are reading longer, look up from time to time to see what is happening around you.
Don't go on reading. Not ever. Not even without a dog. Especially not with a dog running free, possibly behind you where you can't see it. There are enough examples of dogs that know how to exploit this great freedom for their own benefit, even if it means increasing the distance a little (or a little more) and thus becoming a stress trigger for other dog walkers. Even if they only stop a little longer at forks in the path and fixate on anyone who wants to go that way. If the distance becomes too great, most dogs close up again. You didn't notice anything, but other dog walkers did.