For the last month or so, our 6 year old retriever hasn't been his dim, happy, waggy-tailed self. He's very fit, eating well, getting on and off the sofa without trouble, so nothing obvious, but somehow just not normal.
He's sleeping a lot. Is happy once he's in the park, but not desperate to get there as he usually is. He's always been a huge cuddler, but is choosing to spend more time on his own. He's not been snappy, but has been a bit irritated with our other dog, who he's very bonded with.
I took him to the vet for a check a couple weeks ago, and they couldn't see anything obvious, Joints fine, ears fine, mouth and teeth all good. We tried him on a trial of anti-inflammatories to see if that changed his behaviour, i.e. there was hidden pain, but it didn't make a difference.
I'm going to take him back in. Any wise suggestions of what they should be looking for?