Tuesday night I found some big, brilliant lamb bones in the supermarket and gave him the largest (300-400g) that night.
Wednesday morning he did his normal post-breakfast poo. Then another before I left for work at 9am, which is maybe a little earlier than usual, but not unusual in itself. My mum stayed home with him but as she was quite sick, he spent most of the day in the garage as she couldn't watch him. I'd thought he seemed off-colour in the morning and insisted she take him out at some point for a short play as I didn't want him to spend the whole day alone. She took him out for a bit at noon when he did yet another poo.
I got home at 3ish to a foul smell - he'd pooed in his pen. He's never, ever had an accident in his pen before. Hell, he's only ever pooed inside once or twice quite early on when I just didn't open the door fast enough for him. He's extremely fastidious about where he defecates and gets quite anxious if you're not being quick enough letting him about, so of course, I was quite worried. It wasn't diarrhea - still quite firm. The issue seemed to be his ability to hold it in. It was also rather pale and whitish compared to his usual.
Had to take a quick trip to the doctor later that afternoon and came home to yet another accident in his pen. Next morning, he got up for his normal 5:20ish toilet stop. Only a wee then. 20 minutes later, after a quick catnap, I went to give him a frozen kong and there's more poo in his pen.
Bit unsure of the cause, given that, as luck would have it, there were quite a few new foods happening on Tuesday - he'd had a number of peas the day before, started on a new brand of treats, had never had a lamb bone that big and the spoon of chicken mince he'd had that morning may have been in the fridge a day too long. So yesterday I cut down his meals to basics. He had a very small amount of dry food for breakfast. Didn't get his usual Kong when I left for uni. Only got a very small soup bone for dinner. No more accidents. He's been completely fine today as well.
God, I tend to ramble a lot on here. Kudos if you've made it this far!
Anyhow, to get to my point, I just noticed that his poo has returned to it's normal colour this afternoon (didn't look to closely at the rest of today's attempts, to be honest, and I wasn't home for his afternoon toiletings yesterday), and it occured to me that perhaps it was the fault of the fattiness of the lamb, rather than the actual size?
Obviously no one's going to be able to give a perfect answer over the internet, but does that sound like a reasonable assumption - will excess fat affect his stools that way? As it is, I'll be slowly introducing the above suspected foods over the next few days - he has a much smaller and very lean lamb bone for dinner so we'll see how he is tomorrow. Then start back with the new treats and eventually get back to giving him peas. ...peas don't have some laxative effect on dogs that I've missed, do they?