Since becoming pregnant my normally very well behaved 7 year old collie, has stopped listening to me on walks. He becomes obsessed with other dogs and runs round and round them refusing to come back, he is like a man possessed. He is still getting the same distance walks and food as he did before and seems to be fine for my partner when he takes him out but unfortunatley the majority of dog walking falls on me due to our work lives.
Any ideas on how to tackle this? It is obviously frustrating for me but also a bit weird for the other dog owners.