dog refusing to walk-help

[inlectorecumbit]

I have an almost 6 year old cocker spaniel. He has been a typical energetic dog until about a month ago.
Sometimes ( twice yesterday) we go out for a walk and he just stops dead- refuses to move until l let him turn around and lead me back home. He can't be persuaded to go any other way. Now l am talking about 5 minutes into a walk which he seemed to be keen on, not a 10 mile hike.
He doesn't appear to be in pain, no limping and appetite fine.
I had a post about a year ago about a behaviour change (aggression) which has never resurfaced, and at that point he was found to be "lame" by the vet. He was bunnyhopping at that point, but nothing obvious today.
Anyone got any idea what he is up too???

my 5 year old dog started to do this. i put her in the car and took for for a different place to walk, absolutely no problems.

I would assume pain or memory and association of pain.
Needs another trip to the vets to check there's no trapped nerve etc. That might explain the previous aggression too.

update

Not much further on. Vet can't find anything wrong.However l have realised that this is now only happening at night. He gets really excited to go for a walk but when he goes out and realises it's dark he stops dead and then turns to go home. I tried carrying him across to the grassy area that he loves to go to during the day but he is not interested at all, He will go out into the garden quite the thing.

My conclusion is that he has been spooked by something at some point at night and is now scared of the dark.

Maybe stick to daytime walks. Also look at T-Touch online, they suggest a swaddle that you can easily do yourself ( no money involved!) for a dog that feels unsafe for any reason. Helps them to feel more secure. Its worked on quite a few dogs i know. If there's nothing physically wrong then it has to be psychological so you'll need to work on breaking the pattern he's built up.

My 3 yr old dog has started to do similar, will stop and refuse to go any further on certain walks. I think she may have been spooked by something but no idea what.

If it's only at night, might there be a sight issue which is causing a problem?