
Don't worry yourself about it - the majority of dogs can cope with the odd missed day I think!
My lot have them - I have dobes, a rott mix and a very energetic lab X collie - and they cope. I just make sure they're kept busy - bones to chew, games to play, that sort of thing.
They've only had 20 minutes today because of the rain and a computer problem that's kept me busy all flippin afternoon, and they've been switching between snoozing and chewing on bones. No worries