Foaming at mouth and vomiting hog

We have a 4 month old female mangalitsa hog that is foaming at the mouth and vomiting. She doesn't want to eat or drink. Her stools seem formed and normal.
Any help or advice would be much appreciated.
Thanks

Could be she ate something that didn't agree with her - offer her some buttermilk or yogurt or any other source of probiotics. Nothing salty, tho because they can get salt poisoning easily. If you feed her scraps, maybe be careful not to include moldy foods. Most pigs won't eat moldy stuff that would make them sick but some would. Hopefully others who know more will chime in.