Called "navel ill" by horsemen, infection of the umbilical remnants is a relatively common problem in young foals, usually between 1 week to 2 months old.

This infection can occur with patent urachus, an umbilical stump dribbling urine. It is also common in weak foals that cannot rise, due to greater exposure to and contact with bacteria in bedding. Unsanitary handling or aggressive treatment of the umbilicus with antiseptics (after birth) can damage the tissues and set up conditions for infection.

Without prompt diagnosis and treatment, bacteria are showered into the bloodstream from the abscess, and these are seeded into joints and tendon sheaths, resulting in infection in these areas.

Signs of an umbilical infection in the weeks to month-old foal include fever and swollen umbilicus. However, this problem may not be that obvious, as it may only involve the internal umbilical structures. A common presenting complaint is lameness or a painful hot and/or swollen joint.

Diagnosis requires a careful veterinary exam. Ultrasound is extremely useful in diagnosing this problem and is the only way to diagnose more subtle cases. Blood work can also be helpful to support the diagnosis. Part of the work-up of any foal with an infected (septic) joint is careful ultrasound evaluation of the umbilicus.

Once a foal has been diagnosed with infected umbilicus, prompt, thorough and aggressive treatment is needed. Surgical removal of the remnants is an accepted treatment. In all cases, the whole foal must be treated. Infected joints must be managed, and the foal stabilized before surgery is considered.