Over the years I have received thousands of questions in my practice and on the Internet that all boil down to the same thing. Here’s an example:

My senior dog has not had any appetite for two days and today she started vomiting some brown bile. What can I do?

Mike

Chicago Heights, IL

I don’t think the answer Mike is looking for is “go to the vet,” although in his case it’s the only option I recommend — see below. What I suspect Mike and many thousands like him are wondering is something different. Their dogs have vomited and they are wondering whether it can be treated at home or whether they need to go to the vet.

That question, of course, cannot be answered over the Internet. In fact, the only way it can be answered is by applying the most powerful medical tool known to humanity: hindsight. Only after the episode is over will it be possible to completely comprehend how serious it was.

There are many reasons dogs vomit. Some, such as mild stomach upset due to minor dietary indiscretions, are no big deal and will get better on their own. Others, such as a gastrointestinal foreign body, pancreatitis, or a major metabolic problem, can be deadly without veterinary intervention. Also, be aware that sometimes people get confused about whether their dogs are actually vomiting. For instance, I have seen hundreds of cases of kennel cough (no big deal) in which people confused coughing with vomiting. I also have seen plenty of cases of bloat (deadly serious) in which people thought their dogs were vomiting, but were instead trying to vomit without success.

When in doubt, the safest rule always is to go to the vet. But I will confess that significant numbers of dogs who vomit have mild problems that will be self-limiting (in other words, get better without treatment). Although there are no absolutes, there are some rules of thumb you can follow at home.

Vomiting almost always is linked to stomach inflammation (irritation). If a dog’s stomach is inflamed, he will vomit. Also, vomiting makes the stomach inflamed. It’s a cycle that can get out of control if the dog eats or drinks right after vomiting. (Plenty of people have experienced this phenomenon. Remember that time in college when you drank too much tequila and your well-meaning friend kept insisting that you drink water each time you vomited? Maybe you don’t, since tequila was involved. But here’s what happened: You kept on vomiting every time you drank the water.)

So, if your dog vomits once (or even a couple of times in rapid succession), it’s not unreasonable to withhold his food and water for a few hours. If your dog doesn’t continue to vomit and no other symptoms (such as diarrhea) develop, then try offering water once the time has passed. If he drinks and holds it down for an hour, give him a small amount of easily digestible food, such as boiled boneless skinless chicken breast with steamed white rice.

It’s time to hightail it to the vet, however, if your dog keeps on vomiting even when no food or water is available; if he starts having diarrhea or becomes markedly lethargic (or develops any other symptoms); or if he has no interest in water and food once they have been reintroduced, or if he cannot hold them down.

Protracted vomiting, or vomiting complicated by diarrhea or other symptoms, can be a sign of something serious. And it can be serious on its own. Vomiting causes dehydration. It doesn’t help that nausea also usually suppresses thirst. The dehydration can develop fast, and it can get dogs into lots of trouble. Vets can treat (or preferably prevent) dehydration with injectable fluid solutions.

When in doubt, it’s best to get to the vet sooner rather than later.

Got a question for Dr. Barchas? Ask our vet in the comments below and you might be featured in an upcoming column. (Note that if you have an emergency situation, please see your own vet immediately!)