having awoken - I'd put a comma after this
I looked on my watch- at (you could also use 'glanced at')
How marvellously- marvellous
the meadow that we were ambling- needs a preposition- across/over?
was full of moonlight- was moonlit?
to snuff- sniff
which bitch is attractive- bitch is on heat?
I thought that it wasn’t the best idea - to take the dog - had thought (??? when did you think this?) + delete the dash
dog to its own fate- I'd delete 'own'
wallow in a dead frog- it would have to be a huge frog for this to be possible
I do regret to have forgotten- that I had forgotten
batch your dog- leash your dog??
my wallowed dog)- it would be wallowing here, if a dog can wallow in a frog
something was stinking- stank