Ingluviotomy in Birds
An ingluviotomy is a crucial surgical procedure performed on birds to create an opening into their crop. This procedure is particularly employed to extract foreign objects, such as fragments of a feeding tube, from the crop. It's essential for veterinarians to be familiar with the technique, indications, and post-operative care for successful outcomes.
The crop, an expansion of the esophagus in birds, acts as a muscular pouch that temporarily stores and softens ingested food. This storage area aids in pre-digestion through the release of enzymes, gradually passing food to the proventriculus and then the gizzard for mechanical breakdown. From there, food enters the duodenum, where pancreatic enzymes facilitate further digestion. The absence of a gall bladder in pigeons directs bile to the small intestine, aiding fat emulsification. The food eventually reaches the short large intestine before waste is excreted via the cloacae. This intricate process highlights the crop's essential role in avian digestion and nutrient absorption.
Indications for Ingluviotomy:
Foreign Body Removal: Ingluviotomy is primarily conducted to remove foreign bodies lodged in the crop, especially in hand-fed pediatric birds. Larger or older birds may require the use of an endoscope for identification and extraction of crop foreign bodies.
Pediatric Pet Birds and Crop Stasis:
Crop stasis is a common condition in hand-fed chicks, marked by the inability of the crop to empty within a normal timeframe. This condition can be due to poor husbandry, nutritional practices, or underlying diseases. Factors such as cold temperatures, low humidity, and incorrect formula temperature can contribute to crop stasis.
Clinical signs include distended crop, dehydration, regurgitation, and depression.
Diagnosis involves physical examination, palpation, and crop content analysis.
Treatment includes crop emptying, fluid therapy, and tailored feeding strategies.
Pediatric Pet Birds and Crop Burns:
Crop burns occur when hot bird formula is fed to chicks. Microwaving formula is not recommended due to the risk of uneven heating. Crop burns can vary in severity, leading to skin inflammation, blistering, and tissue necrosis. Diagnosis relies on history, clinical signs, and examination. Treatment encompasses antimicrobials, fluids, anti-inflammatories, and nutritional support. Surgical repair may be necessary, involving debridement and closure.
Crop Anatomy and Function:
The crop is an extension of the esophagus that stores and softens food temporarily. It's divided into segments like pre-crop, crop, and post-crop. Different species exhibit diverse crop forms, with chickens having a simple spindle-shaped crop, while pigeons possess two pouches. Food travels through the crop, proventriculus, and gizzard, where digestive processes occur. The esophagus of pigeons is made of endodermal tissue.
Rupture of the Crop:
Crop rupture, often due to injury, is common in pigeons. Ingested foreign objects and Trichomoniasis lesions can contribute to rupture.
Clinical signs include lump presence, food retention, and regurgitation.
Diagnosis involves biopsy or flexible endoscopy. For neonates, crop rupture from tube feeding is possible.
Surgical Approaches:
Performing an ingluviotomy involves several precise steps. The bird is placed in dorsal recumbency with the head elevated and the esophagus occluded using moist cotton or gauze to prevent aspiration. Using a No. 22 blade, an incision is made over the lateral sac of the crop in an avascular area, with the length being approximately half of the desired length, as the crop easily stretches.
There are various techniques for ingluviotomy closure:
1. Single Layer Closure: The ingluviotomy incision and skin incision are closed together using a simple interrupted suturing pattern. Absorbable suture No. 4/0 Vicryl (Ethicon, Johnson and Johnson-International) is used.
2. Double Layer Closure: The simple interrupted pattern is used for closure. The skin is closed separately over the ingluviotomy incision using 4/0 Vicryl (Ethicon, Johnson and Johnson-International) for crop closure, and 4/0 Vicryl (Ethicon, Johnson and Johnson-International) for skin closure.
3. Closure with Glue: In this technique, glue (Dermabond, ETHICON, INC.) is applied to close the wound.
After the surgical procedure, the operated birds are moved to the recovery room for observation. Adequate fluid therapy is administered (Ringer Lactate at a dose rate of 10-20 ml per kg body weight subcutaneously) to ensure proper rehydration and renal function. Injectable antibiotic Cefotaxime sodium (Inj.Claforan, sanofi-aventis) is given at a dose rate of 75-100 mg/kg body weight intramuscularly until the 5th day post-operation.
For analgesia, Ketoprofen is administered at a dose of 2 mg/kg body weight for the first four days intramuscularly. The bird's diet transitions from liquid to semi-solid on the 3rd day post-surgery, and a normal balanced diet is introduced from day 10. Daily dressing is performed until the wound is fully healed.
References:
Husain, R. A study on crop repair by using different Ingluviotomy Techniques in Pigeon. Advances in Animal and Veterinary Sciences. 2020.
The Merck Veterinary Manual. 11th ed. 2016.
Links:
Merk Veterinary Manual
Pediatric Diseases of Pets Birds
