Any time that a young puppy comes in vomiting, I recommend an X-ray. Puppies are famous for eating non-food items. Many of the things that they eat are not dense enough to show up on an X-ray: plastic, cloth, string, paper, etc. Even then, you may see things that make you suspicious of an intestinal blockage.
For instance, half of the intestines look normal, while the other half are blown up with gas and fluid. This can be misleading, of course. Sometimes intestinal infections or inflammations can give the same appearance. A couple of years ago, I did an exploratory on a patient with such an X-ray, and found a nice plastic ball. Ta-da!! ["Thank you, thank you. No, really, you're too kind. Can't help it, really, I'm a genius, you know."]
Two weeks later, I opened a patient with a virtually identical X-ray. Whoo-hoo! I'm on a roll… not. The intestines were really inflamed, but there was no blockage. The gut just wasn't working right due to the infection. Fortunately, the dog recovered in spite of this invasive diagnostic procedure. Maybe airing out the bowels was therapeutic. ["You see, it's the only way to be really sure."]
Still, you need to take that X-ray. I well remember the little 3-pound pup who had been vomiting for 3 days before I saw him. We took an X-ray right away and found a round metallic foreign object, which turned out to be a penny when we did the exploratory surgery. Unfortunately, the copper plating was gone and the puppy was suffering from zinc poisoning. Despite successful surgery, he didn't make it. I don't want that to happen because I fail to recommend an X-ray.
The funny thing is, many times dogs with intestinal blockages don't have any obvious symptoms. That was certainly the case when my own dog, Anna, ate a rock bigger than a golf ball. She'd still eat a treat, but not her regular dog food. She'd play a little, but not much. Never vomited, never strained, wasn't bloated. She wound up losing 2 feet of intestine. Fortunately, a rock shows up like gangbusters on an X-ray, so at least I didn't waste too much time getting her open. [Two days… whoops]
That was the case with Rocky, here, as well. No specific signs you could point to. No vomiting, no nothing. He just didn't feel good, wouldn't eat much. I finally looked at his age (six months = puppy) and asked, "Is he bad to chew on things that aren't food?" "Oh, yes, we have to take stuff away from him all the time." Hey, might as well take an X-ray, then, right? Couldn't hurt, though we probably won't see anything.
Or maybe we will. That's not a hole in the film. That's the kind of shadow that a metallic foreign body makes on film. No radiologist needed here; the neighbor kid could see something wrong from across the street. We found it, but what is it? I'll give you a hint. No matter which direction you take the picture from, the white spot stays perfectly round.
It's the nine-ball, in the corner Chihuahua. The miniature pool table had been confiscated just days before to keep Rocky from playing with it… a day late, apparently. Fortunately (for both of us), the little gum-ball sized billiard ball was made of steel instead of plastic. Got the diagnosis on the first try (after asking one question after another for twenty minutes before I finally thought of taking the X-ray).
Surgery was successful and he made a complete recovery… because we took the X-ray on the first visit.