My black-mouth curr just refuses to poop anywhere that is not our backyard. This is weird because he is only just starting to do this (has only been doing this for a month after pooping on every walk). He is approximately 2 years and 1 month old and has only started after my black labrador has started eating poop. Any idea why this is happening?
I don't know why your dog only does its duty in your backyard. Any number of factors could be affecting your dogs preference including internal factors in his gut that you are unable to see.
I'm reading between the lines here and I think you might like an answer to the question:
How can I get my dog to poop while on a walk instead of when we get home.
Train your dog to poop on command. This will be easy (haha just kidding). To do this you will need to never let your dog outside with out your being there with him. Because you need to be there when he decides to go potty. If you know when he usually goes potty you could modify this to just make sure you are there with him when he usually goes,
Take him out to go potty and when he does say your potty command word right when he squats down. When he is done praise him and give him a treat.
After quite a few repetitions of this you can try giving him the command word for potty towards the end of the walk. Make sure you wait a minute so that he has time to pick a spot and relax. If he doesn't do it, just go home and take him to his usually potty spot and repeat the word. Eventually he should get the idea that you want him to do it on the walk.
I've been doing this with my dog for several months and she will potty on demand IF she needs to go.
We chose a word in a different language because we didn't what to unwittingly say "oh crap" inside the house and have the dog think it was time to squat. :) Not sure if that would really be an issue but I'd rather not find out if it could be.
Lastly, don't forget to take bags so that you can pick up your doggies duty.