Tail rubbing and scratching in pigs is most commonly caused by which parasite?

• A. Tapeworms
• B. Pinworms
• C. Roundworms
• D. Mites

Answer: (B)

Intense perianal itching from a pinworm infection is the main reason pigs tail-rub and scratch. The pinworms live in the large intestine, but the female travels to the perianal area to lay eggs on the skin around the tail. That local irritation triggers the pig to rub the tail on pen walls, bedding, or feed troughs to try to relieve the itch, which can lead to skin damage and crusting around the tail. Transmission occurs when pigs ingest eggs from contaminated environment or bedding, and the eggs can persist, allowing reinfection cycles. Controlling this issue involves treating the herd with appropriate dewormers, cleaning and sanitizing housing, and reducing exposure to contaminated material to break the cycle. While other parasites can cause itching, the pattern of severe perianal irritation and tail-rubbing behavior is most characteristically caused by pinworms.