White frothy substance that you are mentioning can be due to many reasons. Usually it is due to foods and feeding habits of the dogs. One condition called canine bloat can also cause this type of vomiting. Bloat requires immediate treatment because it can leads to death of the dog if not treated on time. Other reason of this condition can be
- Overeating
- Eating rapidly
- Dry foods
- All foods that cause irritations in GI tract
- Stress
- Nervousness
