What Is Your Diagnosis?
A 3-year-old female chicken presented for a 3week history of progressive coelomic distention. Over the 36 hours prior to presentation, the patient was lethargic, showed progressive weakness, and had a decreased appetite. The patient had last laid an egg 2 months prior to presentation, and was otherwise healthy with no previous health concerns. On presentation, the patient was quiet, alert, and responsive, with a decreased body condition score (keel score 2/5) and was 5% dehydrated based on decreased skin turgor. The patient's respiratory rate and effort increased with the stress of handling, but heart rate was low-normal. The skin at the caudal aspect of the keel had hyperkeratinization. The coelom was severely distended and firm on palpation, with a large region of patchy feather loss and erythema caudoventrally. Surrounding the vent extending to the ventral coelom, fetid-smelling, white to yellow cloacal discharge and staining were present. The feather quality was poor with broken primary feathers on both wings and tattered feathers over the remainder of the body.
Physical examination findings were consistent with coelomic effusion. The skin lesions were suspected to be secondary to mechanical injury from the degree of coelomic distention resulting in sagging against the ground; trauma from conspecifics was also considered. Based on physical examination findings and clinical history, a coelomic ultrasound was performed (Fig 1).
Coelomic ultrasound (Toshiba Aplio 500; transducers: PLT-1204BT and PVT-C74BT, Toshiba America Medical Solutions, Tustin, CA, USA) was performed with the patient awake, with minimal manual restraint in a standing position. Sonographically (Figs 1 and 2), the coelomic cavity contained a very large volume of echogenic fluid, which contained suspended echogenicities and sedimentation with a dependent fluid line. Within the caudal coelom, an ovoid peripherally echogenic structure measuring 4.3 cm X 3.0 cm was present, with internal hypoechoic and echogenic content, consistent with a mineralized/shelled egg. Within the egg, an internal fluid line was present matching that within the coelom and gravity dependency. The egg had indented margins at its poles, as well as a discontinuity at the ventral aspect of the shell. At the level of the discontinuity, echogenic material was visible dynamically shifting from within the egg into the adjacent coelom secondary to changes in transducer pressure. An oviduct was not visible surrounding the egg. Adjacent to this larger egg. multiple smaller ovoid peripherally echogenic structures were present, consistent with eggs in varying stages of maturation. The degree of effusion resulted in severe distention of the coelom, which hindered complete assessment of additional abdominal viscera due to depth and patient comfort. The liver, spleen, and ventriculus were visible, and were sonographically normal.
Based on the ultrasound findings, oviductal rupture at the level of the shell gland/uterus with resultant rupture of the ectopic egg and leakage of internal contents into the coelomic cavity was suspected. Therefore, coelomitis secondary to the presence of egg contents was the primary differential for the identified coelomic effusion.
Ultrasound-guided coelomocentesis was performed. Grossly, the coelomic fluid was tan to yellow and turbid with grossly visible flocculent material (Fig 3A). The specific gravity was 1.027 with a protein (by refractometry) of 4.2 g/dL. Cell count was not performed, but based on cytological assessment of direct smears cellularity was low (<1500/[micro]L). Examination of direct smears and cytospin preparations (Fig 3B, C) revealed frequent pale to moderately blue amorphous protein globules with scattered macrophages and mildly degenerate heterophils on a stippled proteinaceous background with protein crescents and moderate amounts of lipid. Cytologic findings confirmed the sonographic diagnosis of coelomitis due to the presence of egg contents. Due to imaging findings, cytologic findings, and poor prognosis, the owner elected for humane euthanasia of the patient. Postmortem examination was not performed.
In addition to reproductive-associated coelomitis, other causes of coelomic effusion include intestinal rupture, congestive heart failure, hepatic failure, neoplasia, hemorrhage, and hypoproteinemia. (1) Reproductive-associated coelomitis is a serious complication of egg laying. Egg yolk coelomitis, a subtype of reproductive-associated coelomitis is caused by the presence of yolk material in the coelomic space. (2) Ectopic ovulation and septic coelomitis encompass the other forms of reproductive-associated coelomitis. (3,4) Ectopic ova may occur due to failure of the infundibulum to receive the ovum, reverse peristalsis, or oviductal rupture. (3,4) Reverse peristalsis can occur for many reasons including oviductal obstruction, neoplasia, cystic hyperplasia, malnutrition, trauma, and stress. (4) Often the egg yolk can be resorbed without the development of clinical signs. (4) However, occasionally the egg yolk can cause inflammation within the coelomic cavity. (4) In addition to resulting in secondary ectopic ovulation, primary diseases of the genital tract can cause coelomic effusion on their own. These include cystic ovarian or endometrial hyperplasia, salpingitis, metritis, oviductal rupture, or neoplasia. (4) Hens with reproductive-associated coelomitis often have a history of egg laying that has abruptly stopped, and can have clinical signs including depression, lethargy, inappetence, weight loss, and coelomic distention. (4)
In the case presented here the ectopic egg resulted from oviductal rupture at the level of the shell gland/uterus given the stage of maturation identified at ultrasound. The egg and the overlying shell had a defect allowing extension of internal egg contents (likely both yolk and albumen) into the coelomic space. This in turn resulted in severe inflammation and effusion.
Radiography and ultrasonography are valuable diagnostic tools in identifying causes of coelomitis and directing therapy. Radiographic findings of coelomitis can include coelomic distention and poor coelomic contrast, but the underlying cause may not be evident if a discontinuous or deformed mineralized egg is not visible. Ultrasonography allows further characterization of the character and volume of coelomic fluid, and assessment of the reproductive tract and eggs if present; it also facilitates sampling of the coelomic cavity. (3-5)
In the case reported here, ultrasound allowed both identification and sampling of the coelomic fluid, and was able to localize the ruptured ectopic egg and source of the coelomitis. Importantly, ultrasound was performed with the patient awake in a standing position, and with minimal stress aside from handling. Ultrasound has been reported previously to aid in the diagnosis of egg yolk coelomitis (6); however, advances in ultrasound technology have vastly improved visualization of the coelomic structures. In this case this allowed for discrimination of the ectopic position of the egg and the site of egg rupture in the addition to the presence of coelomic effusion.
Ultrasound-guided sampling of the coelomic fluid supported the sonographic diagnosis of coelomitis due to egg contents. Cytologically, effusion related to a ruptured egg or the presence of yolk is often characterized by a yellow exudate with round, dark blue amorphous globules as well as fat globules. (1) The inflammatory cells often identified include heterophils, macrophages, lymphocytes, and plasma cells. The round amorphous globules represent protein, which in conjunction with the fat are a key component to diagnosis, as egg yolk is 33% lipid and 17% protein.
Treatment of reproductive-associated coelomitis may involve conservative medical management or intervention, depending on the severity of disease. (4) As yolk material can act as a growth media for bacteria, (2) medical management should include broad-spectrum antibiotics pending culture of the coelomic fluid. While egg contents may be sterile, this can act as a growth media if there is passage of flora from the ruptured oviduct or from the bloodstream. Escherichia coli is the most commonly identified infectious agent. (7) Pharmacologic intervention (such as leuprolide acetate) can be used to prevent further ovulation. (4,7) Coelomocentesis can be therapeutic as well as diagnostic and can help reduce associated clinical signs such as dyspnea. (4,7) Preparation for coelomocentesis should proceed similarly to prior descriptions of ultrasound-guided aspiration of coelomic organs. (8) Coelomocentesis without ultrasound guidance has been described previously (9) and an ultrasound-guided procedure is similar, although it uses the ultrasound image to guide the needle to a target. If a large volume of effusion is present, the procedure can be done awake or under sedation rather than with anesthesia, as the target is avascular and therefore complications are generally less severe.
To perform coelomocentesis, the ultrasound gel used for coupling during diagnostic evaluation is removed. The coupling site is wiped clean with an antiseptic and isopropyl alcohol. Alcohol can be used as a coupling medium for the transducer. A fluid pocket should be identified and Doppler ultrasonography used to determine the location of, and avoid, blood vessels. A needle (typically 22 gauge or smaller) attached to a syringe is placed adjacent to the transducer and advanced into the coelom under ultrasound guidance. The tip of the needle should be visualized throughout the procedure to avoid contact with organs or blood vessels. The contents of the syringe should be monitored during aspiration for evidence of hemorrhage. If a therapeutic coelomocentesis is being performed, an extension set with 3-way stopcock rather than syringe can be used with the sonographer maintaining needle position while an assistant repeatedly aspirates fluid until the fluid pocket is successfully reduced. Additional treatment, including pain management (such as meloxicam, butorphanol, or tramadol), fluid resuscitation, and assisted feeding is likely required. (7) If the coelomic effusion resolves, laparoscopy may be considered to further investigate or confirm the cause of coelomic effusion and to visualize the ovary and oviduct to identify any underlying abnormalities. (4) If the patient does not improve with medical management alone, interventional procedures such as laparotomy may be required to remove an egg, masses, granulomas, or inflammatory debris, or perform salpingohysterectomy (3,4,10) Without intervention, the condition is likely to recur. (7) During laparotomy, masses, granulomas, or a cystic oviduct may be identified, necessitating resection or salpingohysterectomy. Inflammatory debris within the coelom may similarly need to be lavaged and removed. (4) Following salpingohysterectomy, long-term medical management with a gonadotropin-releasing hormone agonist, such as leuprolide acetate, to prevent an active ovary may be necessary to limit further instances of egg yolk coelomitis that occur secondary to ovulation in the absence of an oviduct to receive the ovum. (4)
This case demonstrates the use of ultrasound in minimally invasive diagnosis of coelomitis due to egg contents.
This article was submitted by Ryan B. Appleby, DVM, Sarah C. Roode, DVM, PhD, and Eli B. Cohen, DVM, from the Departments of Molecular and Biomedical Sciences (Appleby, Cohen) and Population Health and Pathobiology (Rhode), North Carolina State University, College of Veterinary Medicine, 1060 William Moore Dr, Raleigh, NC 27607, USA.
(1.) Campbell TW. Effusions. In Exotic Animal Hematology and Cytology. 4th ed. Hoboken, NJ: John Wiley & Sons Inc; 2015:309-321.
(2.) Caruso KJ, Cowell RL, Meinkoth JH, Klaassen JK. Abdominal effusion in a bird [egg yolk peritonitis]. Vet Clin Pathol. 2002;31:127-128.
(3.) Rosen LB. Avian reproductive disorders. J Exotic Pet Med. 2012;21(2): 124-131.
(4.) Bowles HL. Reproductive diseases of pet bird species. Vet Clin North Am Exotic Anim Pract. 2002;5(3):489-506.
(5.) Hofbauer H, Krautwald-Junghanns ME. Transcutaneous ultrasonography of the avian urogenital tract. Vet Rad Ultrasound. 1998;40(1):58-64.
(6.) Powers LV, Degernes LA, Starrak G, et al. What is your diagnosis? J Avian Med Surg. 1996; 10(2); 126-129.
(7.) Calvo Carrasco D, Sabater Gonzalez M. Reproductive disorders in commonly kept fowl. Vet Clin North Am Exotic Anim Pract. 2017;20(2):509 538.
(8.) Nordberg C, O'Brien R. Paul-Murphy J. Hawkley B. Ultrasound examination and guided fine-needle aspiration of the liver in Amazon parrots (Amazona species). J Avian Med Surg. 2000; 14(3): 180-184.
(9.) Orosz SE, Lichtenberger M. Avian respiratory distress: etiology, diagnosis, and treatment. Vet Clin North Am Exotic Anim Pract. 2011;14(2):241-255.
(10.) Mans C, Sladky KK. Clinical management of an ectopic egg in a timneh African grey parrot (Psittacus erithacus timneh). J Am Vet Med Assoc. 2013;242(7):963-968.
Caption: Figure 1. Transcoelomic ultrasound of a female chicken with coelomic distension in standing position, and the transducer oriented in a longitudinal direction on the brood patch, cranial to the left and caudal to the right.
Caption: Figure 2. Labelled images of transcoelomic ultrasound in Figure 1. (A) An abnormally shaped ectopic egg (*) with indented poles is present in a large volume of fluid. Fluid lines within the coelom and egg (arrowheads) demarcate gravity-dependent material from suspended echogenicities. (B) A magnified view of the egg identifies a focal defect at one pole (arrow) with echogenic material crossing the border between the egg and the coelomic cavity.
Caption: Figure 3. Coelomic fluid obtained from the chicken described in Figure 1. (A) Fluid was grossly tan to yellow and turbid with visible flocculent material. (B and C) Amorphous, blue protein globules with mild mixed inflammation on an eosinophilic background, consistent with coelomitis due to egg contents. Wright-Giemsa; (B) 20x and (C) 50x objectives; size bar = 50 [micro]m.
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|Title Annotation:||Round Table Discussion|
|Publication:||Journal of Avian Medicine and Surgery|
|Date:||Dec 1, 2018|
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