Every so often my cat swells up in different areas of his body. Every vet I've taken him to is at a loss. He's been on the venison and green pea allergy diet for a year now, but the problem still persists. Areas of swelling include the head, chest and all four feet, though only one at a time. He does not seem to be in pain during these episodes and walks normally when his foot is swollen. This guy is only two years and nine months old. Anybody have any clues or ideas?