If your dog is vomiting foam, then this could be a result of a serious condition. The foam is potentially coming from both the lungs and the stomach.
Bubbly or foamy vomit is caused either by air from the lungs coming back up with the food, throwing up stomach bile, or vomiting swallowed saliva.
What is causing my dog to vomit bubbles?
Most of the time, if your dog's vomit is bubbly or foamy, then this is as a result of a lack of food in the dog's stomach. This then causes bile or air from the lungs to come up too.
This form of vomit could also be a symptom of pancreatitis, or a heart condition.
The consistency of this vomit could also be the result of a condition in dogs known as bloat - which is potentially life-threatening.
If your dog continues to have bubbles in its vomit, then it would be wise to take it to the veterinary surgery, where they can establish exactly what is causing this to happen.