My Dog Is Throwing Up White Slime. More often than not, this can be a sign of eating too much grass or digesting too much dirt. Determining whether a dog vomiting clear liquid is a problem depends on the other.

The white foam is a mix of saliva and beaten gastric juices. The material may appear to be vomit but could actually be mucus and fluids from the respiratory system. You may also notice your dog having the following signs:

Why Is My Cat Throwing Up Foam. If your cat is vomiting foam, it’s likely to be bile. If there is foam residue around the mouth, it can be due to various reasons such as eating something toxic.

If your cat is vomiting foam, it's likely to be bile. Why is my cat throwing up white foam? Some of the symptoms include constipation, reduced appetite, and gi obstruction.