Egg-binding is diagnosed when the hen cannot pass her egg normally and it is retained in the distal oviduct. If it is the firs egg, spontaneous regression of the second developing ovum usually, occurs. Dehydration of the oviduct develops in longstanding case and prolapse of the gravid (egg-holding) oviduct may result.
Experienced fanciers generally have no problem feeling retained egg in the abdomen. Similar signs are occasionally cause( by a tumour or inspissated yolk, and an incorrect conclusion readily drawn. where doubt exists, radiography of the abdomen will demonstrate the presence or absence of an egg. Lateral and dorso-ventral views are advisable.
The cause of egg-binding is an abnormal egg, oviduct malfunction or abnormal positioning of a normal egg. Abnormal egg include double-yolk or rough-shelled eggs. In oviduct abnormality the eggs are normal, as they are when turned sideways, but cannot be passed because of debilitation from calcium deficiency excessive laying, disease, verminosis or malnutrition.
Oviduct malfunction includes inertia (sluggishness to contract from calcium deficiency, needed also for eggshell formation an( normally withdrawn from the bloodstream and the skeleton. Inadequate dietary replacement affects the nerve network and can lea( to reduced oviduct motility, which may be severe enough to cause egg-binding. Paralysis of the legs is occasionally seen just before and during the laying process, i.e. during shell formation, but is of a transient nature.
Mineral supplementation, particularly calcium, during the breeding season is absolutely essential.
Localised conditions of the oviduct, leading to egg binding include inflammation of the
oviduct, yolk retention and adhesions of the oviduct from previous trauma or infection. An
inflamed oviduct has reduced peristalsis and reduced capacity for
eggshell formation, resulting in rough-shelled eggs, which increases the predisposition for egg-binding.
Treatment depends on how long the condition has been in progress. If of recent origin, the bird is placed in a warm, quiet and dark place and left alone for a few hours. Heat is supplied from a hot water bottle or small electric blanket. Injection of calcium borogluconate (intravenously or intraperitoneally) is usually successful in restarting peristalsis.
Heat and calcium will often resolve the situation. Oxytocin injection (1 - 2 i.u. intramuscular) may be attempted.
Should there be no response to this treatment after about six hours, an attempt is made to deliver the egg manually.
A small amount of oil is introduced into the cloaca via a soft rubber tube and spread gently around the egg. This is not easy but greatly facilitates the delivery. With the bird held in the normal horizontal position, one hand is placed over the back with the thumb and index finger resting lightly on either side of the egg, felt through the abdominal wall. The fingers are slowly brought together and the egg is gently squeezed backwards. Great care must be exercised because the pigeon is severely stressed by this manipulation. One should feel the egg moving backwards and if no progress is made, the procedure is discontinued for fear of excessive stress.
Occasionally the egg is half-delivered and covered by the oviduct (partial prolapse), which is stretched to extremes and paper-thin, and into which a small incision is made that greatly facilitates delivery.
Should the above procedure for delivery not be successful, Caesarian section is safer than continued manipulation and must be performed.
The egg must never be broken forcibly. The sharp edges are harmful to the oviduct and damage can result in inflammation and Peritonitis. Small bits of shell are difficult to remove and excite localised infection if left behind, frequently leading to sterility and pessible fatal peritonitis.