Crop Fistula

Introduction

A crop fistula is a fistula between the crop and the skin, allowing ingested food to discharge from the lower neck region.

It is most likely the result of crop burn due to feeding inappropriately heated food to a baby bird. If using a microwave, the food might not have been heated evenly, and even though the temperature of the food has been apparently tested, pockets of extremely hot food may still be present.

This causes thermal burns to the wall of the crop, which become a fistula once the burn has healed and the scab has fallen off.

Clinical signs and diagnosis

The first signs of a problem are noticed when food is seen discharging from the lower neck region.

Birds affected are usually being syringe-fed and are usually bright, alert and active.

Treatment

Initially, treatment is supportive and geared towards treatment of shock and sepsis. It is important to allow the wound to form fully before surgical repair is attempted as otherwise further tissue necrosis may occur and the wound will break down.

Any necrotic areas should be debrided so that the edges of the wound are easily defined. The crop and skin edges should be separated under general anaesthesia, and each repaired in turn.

The crop is repaired with a double row of inverting sutures using monofilament soluble material and the skin is closed with simple interrupted non-absorbable material.

It is important to ensure no food is trapped between the crop and the skin as this could result in subcutaneous necrosis.

A pharyngostomy tube can be put in place post-operatively to aid recovery and the provision of nutrition.

References

Girling, S. (2004) Avian Practice: Diseases of the digestive tract of psittacine birds In Practice 26:146-153

Coles, B. (2007) Essentials of avian medicine and surgery John Wiley and Sons

Rosenthal, K. (2008) Rapid review of exotic animal medicine and husbandry Manson Publishing