Pear Ball?

I've heard of Hardware disease in cattle from them swallowing something along the line of hardware. As in a rusty nail being caught in a bale of hay and a cow accidently swallows it while eating hay but a pear ball? When John was looking for a baby calf he came upon some cow bones and there was a pear ball with the bones. I hope to see it tomorrow and take a picture of it. John said they sometime happen to swallow a whole cactus pear without chewing it up and digesting it. Food keeps wraping around it and it keeps getting bigger and bigger. Then the cow feels full and doesn't eat and gets weak and dies. Today we met the renter girls walking their birds and stopped to talk to them and admire their birds. They do have dogs but they walk their birds with them riding on their finger or shoulder. I don't know what kind they are. Not a parakeet and not a parrot but somewhere in between. They walk in the hot part of the day for exercise which they need. They carry a mist bottle and squirt the birds when they get hot. They say the birds let them know when its time to mist by hollering what sounds like "hot". They have their wings clipped and are very tame so they don't fly away.