Reproductive Disorders of Pet Birds

The cloaca is the common chamber at the end of the intestinal tract into which the reproductive, gastrointestinal, and urinary tracts empty. The vent is the opening of the cloaca through which droppings (and eggs in females) pass to the outside. The cloacal (or vent) lips control the opening of the vent and thus the frequency with which a bird passes droppings. Both the cloacal lining (in both males and females) and the oviduct (in females) can abnormally protrude through the vent to the outside. Prolapsed tissue may cause chronic straining, obstruct the passage of droppings and eggs, and become dried out and necrotic. Both psychological and physical factors may contribute to tissue prolapse, and affected birds should be treated by a veterinarian immediately.

This syndrome is extremely common in adult Umbrella and Moluccan cockatoos. The exact cause has not been determined, but birds that develop cloacal prolapses are frequently hand-raised, had delayed weaning and/or continued begging for food, have a close attachment to at least one person (with signs of either a child/parent or mate/mate relationship with the person), and have a tendency to hold the stool in the vent for prolonged periods (for example, overnight), rather than defecating in the cage. Cockatoos that live separately from humans do not typically have this medical problem. Although there are numerous factors that may contribute to cloacal prolapse, both emotional factors (commonly related to a bird’s misplaced sexual attraction to a person), as well as an owner’s inadvertent rewarding a bird’s holding stool in the cloaca for prolonged periods (causing stretching and dilation of the vent), are thought to play a role.

Cloacal prolapse, cockatoo

If detected and treated early, surgery and behavior modification can correct the problem. However, behavior modification is often difficult for owners because in many ways it involves breaking the close bond that they have with their bird. If the bird still perceives its owner as either parent or mate, it will continue to strain and the problem will likely recur. Behaviors that may send a confusing sexual message to a bird and that should be avoided include petting the bird’s body (other than on the head), cuddling the bird close, and offering the bird warm foods (as a cagemate might when regurgitating food as part of courtship). If an owner is serious about trying to change their bird’s behavior, the aid of a behavioral consultant will likely be necessary ( see Where to Get Help).

Egg binding occurs when a bird is unable to expel an egg from the reproductive tract. It is most commonly seen in overweight, female birds that get little exercise. Chronic egg layers can develop a calcium deficiency, which is a contributing factor often seen in birds with this condition. Other contributing causes include vitamin A deficiency, oviductal disease or neoplasia, abdominal wall hernia, being a first-time layer, and genetic factors. An inappropriate environment and lack of a nest box can be contributing factors for some birds. Cockatiels, budgies, and lovebirds are commonly affected, but larger parrots may also experience egg binding.

Signs of egg binding include a bird’s sitting on the cage bottom, acting weak and lethargic, straining to defecate, passing bloody droppings, having difficulty breathing (manifested as tail bobbing), abruptly ceasing to lay eggs, and having a visibly swollen abdomen.

A veterinarian will likely take an x-ray to determine the size and position of the egg and will provide calcium, fluids under the skin, lubrication in the vent, and a warm, humid environment to encourage the bird to pass the egg. If the egg does not pass, the veterinarian may need to sedate the bird to try to manually extract the egg through the vent or fully anesthetize the bird to surgically remove the egg from the abdomen.

Also see professional content regarding reproductive disorders of pet birds.