What dog owner hasn’t experienced that oh-so-special early morning wakeup call of stepping her foot in dog puke? If you’re like me, you first recoil in disgust but then inevitably end up on your hands and knees examining the offending puddle for clues as to why your dog is throwing up. The vomit in question is often foamy or watery, and yellow in color. So, what does a dog vomiting yellow mean?

Dog vomiting yellow? Here’s why

That yellow stuff is actually your dog vomiting bile. “Bile is produced by the liver and aids in the digestive process,” explains Tracey Jensen, DVM, Dipl. ABVP, medical director at Wellington Veterinary Hospital in Wellington, Colorado. “Bile is normal, but it’s not normal to vomit bile. The bile itself, if it’s produced excessively, can be a cause of vomiting.” 

Why is your dog vomiting bile? What is bilious vomiting syndrome?

I asked Dr. Jensen about my own dog, Jäger, who occasionally vomits bile if he goes too long without eating. It usually happens in the morning if I fed him dinner earlier than usual and forget to give him breakfast right away. I once Googled it and discovered the term bilious vomiting syndrome. In dogs, bilious vomiting syndrome is vomiting as a reaction to inflammation caused by bile in the stomach. Dogs with bilious vomiting syndrome tend to throw up in the morning after they haven’t eaten in a while. I wondered if that could be what causes my dog’s weird early-morning barfing.

“It’s one of the things on a very long list of 1,001 reasons why a dog will vomit,” Dr. Jensen says, “and it certainly can be that a particular pet produces enough acid on an empty stomach that it will trigger vomiting. That is something that can be managed by a regular feeding schedule or even antacids.”

Now that I know that Jäger seems to do better with food in his stomach, I try to make sure I feed him his breakfast and dinner at the same time every day. If for some reason I have to feed his dinner early, I’ll give him a biscuit right before bed and that usually does the trick.

Is your dog throwing up yellow a cause for concern?

One thing to know — your dog vomiting yellow may be a symptom of something serious. If your dog vomits, even occasionally, he should be seen by your vet to make sure it’s nothing that requires treatment. “It takes more of a trigger for a dog to vomit than most people,” Dr. Jensen says. “If a dog has started vomiting, usually there’s something that triggered that and the possible causes for vomiting in dogs is quite an extensive list.”

Your vet will do a complete physical exam and might recommended certain tests to look for common causes of vomiting. According to Dr. Jensen, vomiting can be caused by certain parasites, various organ issues, hormonal disturbances and food sensitivity.

Should you take your dog to the vet if he is puking yellow?

It’s hard to know when to bring your dog to the vet and when to take a wait-and-see approach. If there is a problem than needs to be addressed, waiting too long can lead to a more severe issue and could cost you more in the long run.

“Pets can’t speak,” Dr. Jensen says. “All we really have to go on are these physical symptoms. If something is occurring in your pet that has never happened before, pick up the phone and make a call. Even if it’s just a one-time thing. If nothing else, it will then get noted in your pet’s file in case it does develop into a trend.”

Thumbnail: Photography by Shutterstock.

Read more about dog vomiting issues on Dogster.com:

• All About Dog Gastrointestinal Issues — Diarrhea, Vomiting, Constipation and More
• Why is My Dog Throwing Up White Foam?
• Ask a Vet: My Dog Is Vomiting. When Do We Go to the Vet?