Animals don't think: "Oh, that's just cute Mrs. Fluffee Wuffles down there...". They think: "Uh oh, over forty slavering hairy carnivores regularly walk through this area like they own it, and half of them leave smelly shit behind... so I'm going elsewhere..."
Researchers have known for a long time now that dog-walking permanently scares away around a third of all the birds from conservation areas. Now it seems that a wider and clearer scientific case for banning dog-walking is developing. Especially in country parks and nature reserves, and on coastal and river paths. Dog walking in such areas clearly needs to be banned on ecological grounds, if our nature reserves are really meant for nature as intended.
There are further, invisible effects. For instance various compounds used to de-lice, de-flea and otherwise clean tens of millions of dogs are polluting British rivers and damaging the water-fauna that live in the water. These wash off the dogs on washing in driveways or paddling in water, are extremely toxic (Fipronil and Imidacloprid), degrade to even worse forms, and are widespread in all UK rivers.