Your dog isn't just throwing up, he's throwing up a foamy, yellow substance that looks like something out of a horror movie. What's a concerned dog-parent to do? Take notes on what your dog is eating, how his body is responding, and any other information a veterinarian may need to help you both out in a hurry.

1. Food Allergies

From fillers and additives found in dog food ingredients, any dog can suffer an allergic reaction to food, just like their human companions. An allergic reaction is an immune response, involving inflammation and an overproduction of bile. Unfortunately, this scenario causes queasiness and, ultimately, an icky expulsion of bile juices. If your dog appears to be having an adverse reaction to his diet, a consultation with the vet is in order, to discover the exact allergy and what other foods may be more appropriate. 

2. Too Much Fiber or Fat

Since bile is produced by the liver, the organ responsible for managing fat, if your dog's diet is high in fat, creating problems for the liver, upchucking may result. Your dog should be fed only products formulated specifically for his species, as opposed to table-scraps. Likewise, an animal that's consuming an excess amount of fiber could experience liver/bile complications, as the fiber changes the rate at which food is processed, thereby offsetting the usual internal balance.

3. Eating Grass

The act of chewing and swallowing produces stomach acids, but when the only thing consumed is grass, the volatile acids overtake the digestive process, usually resulting in a quick hurl. Sometimes, a dog with an upset stomach may eat grass to induce vomiting. So long as this isn't occurring often, you probably don't need to panic, though you should bring it up with the dog's doctor if it becomes a consistent problem.

4. Eating Too Much Dry Food

If a kibble has ever found its way to your dog's water bowl, you've seen with your own eyes how the dry food can suck up moisture, puffing-out like an over-soaked sponge. That can happen in the tummy as well, and when there's more dry food than moisture, acid production can run rampant, leading to a minor or major case of that yellow-ish vomit. Find a nice balance between your dog's canned and kibble food, or speak with someone at the veterinarian's office.

5. Not Eating Enough of any Food

Bile may accumulate in the stomach when it's empty, along with a steady inflammation. When this goes down, the bile often comes up, especially if the dog eats a meal quickly, such as first thing in the morning. If you observe this pattern of an empty stomach seemingly causing vomiting, try giving the dog a small snack before bedtime or a smaller breakfast, to make the breaking of the overnight fast easier on his stomach.

Vomit is always a concern; however, when it's bright-yellow and foamy, it's even more concerning. Gather as much data as you can, then call services such as Pittsburgh Spay & Vaccination Clinic right away.