Our 8 year old male dog started vomiting his food, pretty much every day, so took him to our regular vet who said his prostate was enlarged putting pressure on his stomach, so he needed to be desexed. Went ahead as advised and had him neutered but the vomiting continued, so now he's getting an ultrasound to check his stomach. Funny thing is, other than the vomiting he seems perfectly healthy, he has a good appetite, is alert and doesn't appear to be in any pain. We've tried changing his diet but nothing seems to work. I'm hoping that the vet knows what they are doing, but it's a worrying time.