If a healthy dog is vomiting, typically they’ve eaten something stupid — such as a rock. - AdobeStock

“Hi, Boomerang,” I greeted the big tan dog in my exam room. But wait. The person sitting beside the husky greyhound cross wasn’t her usual human. Was I confused? Was this another dog? A Boomer lookalike? The gentlemen accompanying the dog quickly clarified. Boomerang’s owners couldn’t bring her in today. Since he spent a lot of time with the dog, he was here, in loco parentis.

“So what seems to be the problem?” I asked, beginning my examination, “I’m not with her all the time,” Boomer’s buddy said, “but she’s been throwing up a lot for over a week.” He proceeded to elaborate on her adventures. Boomerang had been eating grass, then barfing. She had scarfed down some fish bones on the beach. She also devoured a yummy pig’s ear chew. Once when she puked, he had seen blood in the vomitus.

I sighed. Audibly. Where to begin? “First of all, don’t let her eat grass,” I advised. There are many theories about why dogs eat grass. None proved. None universally accepted. A healthy dog occasionally munching on the lawn probably is just enjoying his greens. That’s fine, as long as the yard hasn’t been treated with pesticides or other harmful chemicals, and as long as it doesn’t make him vomit repeatedly. At other times, ingesting grass may be a response to gastrointestinal upset. This behavior makes evolutionary sense. Say you are a wolf who has eaten something rotten or toxic. You feel nauseated. If you eat enough fibrous plant material to make you vomit, this may purge the noxious material from your system. You then have a better chance of surviving (and reproducing) than that other sick wolf who didn’t eat grass and barf the bad stuff.

Sometimes that instinct goes a little haywire. If a dog has already been vomiting for days, further upchucking isn’t useful. On the contrary, Boomerang is caught in a nasty cycle. She feels sick and eats grass. The grass irritates her system. She vomits. The repeated vomiting makes her feel sick, so she eats more grass. And so on. It’s up to us humans to break this cycle. “Don’t let her eat grass,” I repeated. Then there’s the pig’s ear. I know. Your dog loves ’em … but they have a high risk of bacterial contamination. I have seen more dogs sickened by pig ears than just about any other treat. Skip ’em. Finally, dead fish at the beach? Need I say more? Poor Boomerang. Any of these could be causing or exacerbating gastroenteritis.

Physical examination didn’t reveal much. Her temperature was normal. She was well hydrated. No abdominal pain on palpation. “We have two options,” I told her caregiver. Option A was a full diagnostic workup with blood tests and radiographs. Option B: No tests, just empirical treatment for “nonspecific gastroenteritis” including an anti-emetic injection (i.e., a shot to stop the vomiting), antibiotics and/or gastroprotectants, and special dietary instructions … and see if she improved. Which option should we choose?

Twenty-five years ago I treated a little terrier who, like Boomer, had been vomiting for days. Like Boomer, Terry’s physical exam was not remarkable, so I was not overly concerned, and we went with Option B. But Terry didn’t improve. I continued to focus on symptomatic treatment with a presumptive diagnosis of gastroenteritis. I was wrong. Eventually the true cause of Terry’s illness was determined: acute kidney failure, a life-threatening metabolic disorder that can also cause vomiting. Had I gone with Option A at the initial visit, we would have known this immediately.

On the other hand, there is a saying in medicine: “Common things happen commonly.” The vast majority of (otherwise healthy) vomiting dogs really do just have upset tummies, usually from eating something stupid, but not deadly. Symptomatic care will fix them up in a day or two. Think about it. If you go to the doctor with a stomach bug, he or she doesn’t typically order x-rays or bloodwork right away. If we were to advise extensive lab tests and radiographs for every vomiting dog, well, I would be able to afford that swimming pool my daughter wants, but my clients, if not questioning my ethics, would at least be questioning their vet bills.

Boomerang’s buddy and her owners (by telephone) made it easy for me, choosing Option A. Good for them. Good for me. And especially good for Boomerang. Though her bloodwork was fine, the first radiograph showed a dense oval object the size of a goose egg in Boomer’s stomach. “Looks like she swallowed a rock,” I said.

I once saw a golden retriever with a weeklong history of vomiting and malaise. Radiographs revealed a rock the size of a baseball in his stomach. His owners weren’t surprised. “He does chew on rocks,” they said. “And we’ve been at the beach a lot.” We started medication, and scheduled surgery for the next day. But when the family arrived the following morning, they were hesitant. “Suddenly he seems to be feeling much better,” they reported. I told them the rock was way too big to pass out of Goldie’s stomach without surgery, but since the cardinal rule about foreign bodies is to x-ray immediately before cutting (in case the object has moved), we took a presurgical film. Guess what? The “rock” had disappeared. It actually was a big wad of sand that had finally broken up and was now moving down and out in a thick trail through Goldie’s intestines.

When is an upset tummy not an upset tummy? When do we choose Option A versus Option B? When is a rock not a rock? Fortunately, I sometimes learn from my mistakes. We took additional radiographs of Boomerang, and gave oral lubricants, antivomiting drugs, and medications to protect her gut. Followup films 24 hours later confirmed that her “rock” was like Goldie’s — an accretion of sand (probably ingested with that fish). Irritating, yes, but not requiring surgery. I’m happy to report Boomerang has bounced back and is feeling fine again.