yes Toby often gets this hun, and i put it down to hes not eaten enough food, or even no food that day, because its just yellow bile and no bits of food in it.
he is the laziest dog in town and it wouldnt surprise me if he didnt get up off his bum and went to the kitchen to eat. sometimes gets this late morning if he hasnt been bothered to get up and eat his breakfast. so then i will stand and make sure he has something to eat then hes fine. i put it down to this because when ive actually seen him eat his meals, theres no yellow foam coming up.
ive just noticed youre from newcastle, im from co.durham