"Tia" - Minorca Chicken with Prolapsed Cloaca
In August I was presented with a quite unusual patient. Tia, a Minorca chicken, had been brought in by her owners because she was straining, and they were worried she might be egg bound. On examination a large red mass was visible at her backend, indicating a prolapsed cloaca.
The cloaca is the organ in birds where the bowels as well as the urinary and genital tract end. Trauma to these internal organs that are prolapsed can seriously affect the bird. It requires immediate replacement back into the abdomen.
In Tia's case it was due to an abnormal egg with a soft shell being trapped in the womb, which was confirmed by x-ray. Because the organ was prolapsed, you can see the contours of the egg outside the body at the back end.
This can occur when there is a deficiency of calcium in the blood and tissues. However even when adequate calcium is available, it may still occur because the amount of calcium required for egg shell production is greater than the amount of calcium a bird can eat in a 24 hour period. The low levels of calcium in the blood affect all muscles of the body. They become weak and contract poorly. The womb cannot contract enough to deliver the egg. This is a serious problem requiring immediate veterinary care.
Tia needed immediate warming as these birds can go in shock. She was anaesthetised and the egg was surgically removed via an hysterotomy, whereby the uterus was incised. After suturing the wound the prolapse was gently manipulated back into the abdomen, and a special suture was used to prevent it from coming out again - however it had to be loose enough to allow droppings to pass.
The suture was kept in for several days to allow the prolapsed tissue to heal, and Tia got extra calcium.Still the prognosis is often poor, because there is a good chance that in the next 24 hours another egg will pass.
In Tia's case all the upset caused her to stop laying eggs for a while, which was fortunate at the time.In October, Lisa, the daughter of the owners, started her work experience at the practice, and you can image my delight when she brought 5 eggs in for me, all laid by a fully recovered Tia.
BVMS, Cert SAO, MRCVS