What does it indicate if a cow is foaming at the mouth? Other symptoms include Decreased appetite, lethargic and increased work of breathing. Calf is 4 months old, born on the farm. Is fed bread, round bale hay and fresh water. Is still sucking from mom and is in with 20 other cows not displaying any illnesses. Calf started with this yesterday and made it through the night. Any thoughts??? Thanks...By the way I am new to cows