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A 42-year-old African grey parrot (Psittacus erithacus) weighing 358 g and of unknown gender was presented to the Division of Zoo Animals and Exotic Pets of the University of Zurich with a 2-year history of a nonhealing skin wound involving the cloaca, cloacitis, and recurrent cloacal impaction. The parrot had been treated previously for cloacitis with cloacal flushes and antibiotics. The owner had observed blood in the feces, and defecation had seemed to become more painful shortly before the current presentation.
On clinical examination, the bird had a body condition score of 3 out of 5. It was depressed and sitting with ruffled feathers. An open skin wound approximately 0.5 cm in diameter was present around the cloaca, extending through the cloacal sphincter. The entire area comprising the cloaca was swollen and reddened. Blood was evident in the feathers surrounding the vent, but the exact origin of the blood was not obvious at the time of the physical examination. Survey radiographs and an endoscopic examination of the cloaca were performed (Figs 1 and 2). A blood sample was submitted for measurement of blood lead level, but because of financial constraints, other blood tests were not performed.
[FIGURES 1-2 OMITTED]
The survey radiographs revealed a dilated proventriculus and a mass approximately 1 x 1 cm in the region of the cloaca (Fig 3). Radiographic density of the mass was between soft tissue and mineral density.
[FIGURE 3 OMITTED]
Differential diagnoses for the mass in this African grey parrot included cloacolith, papilloma, neoplasia, abscess, or foreign body. After radiographs were taken, an endoscopic examination of the cloaca was performed. The bird was induced and maintained on isoflurane anesthesia. For endoscopic examination, the cloaca was flushed with a warm, sterile saline solution, and a 2.7-mm-diameter rigid endoscope (Karl Storz & Co, Tuttlingen, Germany) was inserted into the cloaca. The mucosa of the cloaca appeared inflamed, and minor manipulations resulted in bleeding. The mass observed in the radiographs was visible as a grey-white stone with a rough surface. No evidence of papilloma or neoplasia was identified. The stone, 1.2 cm in diameter, was carefully removed in toto with a forceps while flushing the cloaca.
A crop biopsy was negative for histopathologic evidence suggestive of proventricular dilatation disease (PDD). The blood lead level was within reference range.
Impaction of the cloaca can result from a variety of causes, including failure to pass an egg, intrinsic disease of the cloacal wall, loss of muscle tone due to viral-induced ganglioneuritis (eg, PDD), (1) and a cloacolith.
Cloacoliths are firm, rough-surfaced aggregations of urates. They are uncommon, and the pathogenesis is unclear. (2) The stones may result from prior egg binding, infectious cloacitis, or neurologic abnormalities of the cloaca. (3) In addition, cloacoliths may form in the cloaca because of chronic dehydration and anuria. (4)
In this parrot, there was no history of egg binding, and the cause of the cloacolith was unknown. Although the crop biopsy was negative for PDD, this could not be completely ruled out. The most plausible explanation for the distended proventriculus, assuming the bird was not PDD-positive, was enlargement due to chronic obstipation.
The skin wound around the cloaca resulted from automutilation. Based on the history provided by the owner and physical examination results, the cloacitis was suspected as the nidus for the automutilation but not the underlying cause of the cloacolith. The bird had behaved normally and had a normal appetite until the 2 days before presentation. Therefore, chronic dehydration and anuria were unlikely as a cause for this presentation.
Removing the concretions under general anesthesia is the recommended treatment for cloacoliths diagnosed in avian patients. If removing the cloacolith in toto is not possible, it can be fragmented with forceps and removed piecemeal. The cloaca should always be flushed with warm, sterile saline solution to ensure that the entire mass or fragments are completely extricated.
Perisurgical analgesia consisted of a single injection with carprofen (4 mg/kg, SC; Rimadyl, Dr E Graub AG, Bern, Switzerland). The cloacitis was treated topically for 5 days with diclofenac/gentamicin ophthalmic drops (2 drops q12h; Voltamicin, OmniVision, Geneva, Switzerland) applied directly in the cloaca. The skin was cleaned with a topical solution for wounds and otitis externa, containing acidum malicum and acidum benzoicum (q24h; Dermaflon Solution, Graub). Although the droppings returned to normal and the cloacitis improved, the parrot was discharged with a guarded prognosis because of the possible recurrence.
One year after cloacolith removal, the bird appeared healthy, based on owner evaluation and physical examination. According to the owner, the skin wound appeared to have affected the cloacal sphincter resulting in reduced sphincter function. The consequence of the reduced cloacal sphincter function was persistent soiled vent feathers that the owner cleaned daily. Because this bird was hand tame, the daily cleaning involved very little overt stress.
This case was submitted by Cornelia Christen, DMV, and Jean-Michel Hatt, DMV, Dipl ECAMS, Division of Zoo Animals and Exotic Pets, Department of Small Animals, Vetsuisse Faculty University of Zurich, Winterthurerstasee 260, 8057 Zurich, Switzerland.
(1.) Schmidt RE. Pathology of gastrointestinal diseases of psittacine birds. Semin Avian Exot Pet Med. 1999;8: 75-82.
(2.) Forbes NA. Avian gastrointestinal surgery. Semin Avian Exot Pet Med. 2002;11:196-207.
(3.) Speer BL. Diseases of the urogenital system. In: Altman RB, Clubb SL, Dorrestein GM, Quesenberry K, eds. Avian Medicine and Surgery. Philadelphia, PA: WB Saunders; 1997:625-644.
(4.) Girling S. Diseases of the digestive tract of psittacine birds. In Pract. 2004;26:146-153.