Reproductive Disorders of Pet Birds

The cloaca is the compartment inside a bird’s body that the reproductive, digestive, and urinary tracts empty into. The cloaca has an opening to outside the body that's called a vent. Droppings and eggs pass through the vent.

In both males and female birds, the cloacal lining can temporarily protrude through the vent opening when a bird passes droppings. If the lining gets stuck bulging out of the vent, it is called cloacal prolapse.

In females, the oviduct (the tube leading from the ovary to the uterus and then to the cloaca) can also prolapse through the vent. The part of the oviduct sticking out through the vent can block droppings and eggs from passing through, causing the bird to strain when trying to defecate or lay eggs, and can dry out or die off. This condition requires immediate veterinary care.

Cloacal prolapse is very common in adult umbrella and Moluccan cockatoos. The exact cause is unknown, but many affected birds share certain histories: they are often hand‑raised, weaned late, continue to beg for food after weaning, form very close bonds with one person (acting as if the person is a parent or mate), and tend to hold in their droppings for long periods, such as overnight, instead of defecating in the cage.

Cockatoos deprived of close human contact rarely develop cloacal prolapse. Emotional factors, including misplaced sexual behavior toward a person, along with owners unintentionally rewarding birds by praising them for holding in feces, are believed to play major roles in the development of cloacal prolapse.

If cloacal prolapse is detected and treated early, it can be corrected both with behavioral changes and with surgery to put the cloaca back into place within the vent. Behavioral changes typically include petting the bird only on its head and not on its body, so that you don't accidentally send the bird sexual signals. You should also avoid offering the bird warm foods like a mate would during courtship feeding. If you are serious about behavior modification in your bird, seek help from an experienced avian veterinarian or other behavior consultant.

Behavior modification can be difficult in birds, especially if they are closely bonded to human family members. If, after surgery to repair cloacal prolapse, behavior has not been modified and the bird still perceives a person as a mate or a parent, the bird might continue straining, and prolapse might recur.

Egg binding occurs when a female bird can't pass an egg and the egg is retained within the bird's body. It is most common in overweight, inactive birds. Calcium is necessary to form the hard shell around an egg just before it is laid, so birds that have a calcium-deficient diet or that have laid numerous eggs one after another can become deficient in calcium and then later become egg-bound.

Other causes of egg binding in birds include vitamin A deficiency, oviduct (the tube that runs from the ovary to the cloaca) disease or tumors, abdominal hernias, production of overly large or improperly positioned eggs, and genetic factors. An improper environment and lack of a suitable nest box can also play a role. Cockatiels, budgerigars (budgies), and lovebirds are commonly affected, but larger parrots can be as well.

Symptoms of egg binding include sitting on the cage floor, weakness, low energy, straining, bloody droppings, difficulty breathing (manifested as the tail bobbing up and down), a sudden stop in egg laying, and a swollen abdomen.

Veterinarians often take x‑rays to determine egg size and position in egg-bound birds. They might give the bird calcium and fluids, lubricate its vent to help pass the egg, and place the bird in a warm cage with a humidifier to encourage the egg to pass. If these measures fail, the bird might need to be sedated so that the egg can be extracted manually through the vent or might have to be fully anesthetized for surgical removal of the egg through an incision into the abdomen.

• Also see professional content regarding reproductive disorders of pet birds.