The Wild Side: Introducing VPN's new quarterly exotics section. Many birds are prey species, and thus are masters at concealing signs of illness. While this trait benefits their survival in the wild, it often delays veterinary intervention for captive birds until the underlying disease process is advanced and potentially life-threatening. Veterinarians then must face an uphill struggle with advanced illness in a decompensated patient presented on an emergency basis. But despite those limitations, positive outcomes can still be achieved with appropriate and swift treatment! This article reviews some of the common emergency presentations of birds, focused specifically on pet psittacines. Hemorrhage Figure 1: A broken blood feather is shown, with the larger feather shaft that was broken off and the smaller base of the feather which was removed with the hemostats shown. Note the rounded proximal aspect of the base of the feather, which indicates the complete feather has been removed.Photos courtesy Olivia Petritz Acceptable blood loss, either through venipuncture or hemorrhage, is approximately one percent of the body weight in a healthy bird, or 1mL per 100 gram of body weight. For reference, the average cockatiel weighs 80-100 grams. While most avian species seen in private practice are significantly smaller than dogs and cats, birds have several anatomic differences that compensate for their small size and blood loss. On average, their PCV is higher (45 to 50 percent), and their red blood cell lifespan is much shorter, with a half-life of 30 to 45 days. Birds have been shown to rapidly recover from experimentally induced blood loss. For example, after the removal of about 30 percent of the estimated blood volume of Japanese quail (Coturnix coturnix japonica), erythrocyte numbers recovered to baseline values within several days.1,2 One of the most common emergency presentations of hemorrhage in the avian patient is a broken blood feather. A blood feather is a growing feather containing an artery and vein within the shaft; therefore, if this feather shaft is damaged, it can lead to significant acute hemorrhage. On initial presentation, the first step is to control the hemorrhage either with digital pressure or with a bandage. Alternatively, you can apply Kwik-stop (or similar product) or silver nitrate to the end of the feather for temporary hemostasis. To prevent recurrent hemorrhage, the blood feather should be completely removed. This is accomplished by grasping the base of the fractured feather with fine-tipped hemostats, and provide gentle but firm traction (Figure 1). As the primary and secondary remiges (flight feathers) are attached to the periosteum of the underlying bones in the wings, analgesia should be considered. Complications, although rare, include incomplete removal of the feather follicle or failure of the feather to regrow. Dyspnea The initial physical exam of any dyspneic patient is often brief. Therefore, it is important to maximize the data that can be collected in the first interaction with the patient. Brief observation of the bird in the carrier is always important to help characterize the dyspnea (see below) and obtain a respiratory rate. The bird’s mentation and stance (normal or wide-based) should also be recorded. Are the wings held out from the body or in a normal position? Is there open beak breathing or a tail bob? The clinician must then determine the stability of the patient for manual restraint for additional diagnostics or therapeutics. Figure 2: This adult female cockatiel was presented for progressive dyspnea, and significant coelomic distension was present on physical examination, as shown in this photo. The distension was caused by coelomic effusion secondary to reproductive tract disease. If possible, flow by oxygen supplementation should be delivered during manual restraint for the physical. The bird should always be maintained in an upright position throughout the exam. The key points to focus on include auscultation (heart, lungs, ventral air sacs), palpation of body condition, and coelomic palpation. Remember, as birds do not have pulmonary alveoli, they cannot have “crackles” as you could auscultate a mammal with pulmonary disease. Crackles and other similar sounds may be auscultated in the air sacs if fluid is present within or around these structures. As with other species, audible wheezes or other abnormally loud respiratory sounds are often attributed to upper respiratory disease. A bird with a thin body condition score is more likely to have a chronic condition even if the owner presented the patient for an acute illness. The presence of coelomic effusion may require more immediate treatment than just oxygen supplementation, including coelomocentesis, to improve the respiratory effort. If the bird remains stable, the clinician can proceed with a more thorough physical exam. If not, the bird should be placed in a warm incubator with oxygen supplementation. It is also important to monitor the bird briefly after manual restraint to help determine its stability for future restraint—how did the bird recover? There are several published criteria for divisions of avian dyspnea.3 I prefer to use a combination of these criteria in clinical practice. One of the first clinical decisions to make for a dyspneic bird is whether or not an air sac tube is required. To help determine if this is an appropriate treatment, the bird’s respiratory pattern can be classified as obstructive or restrictive. Obstructive respiratory pattern: Acute to peracute onset, often in good body condition Audible wheezing, +/- loud inspiratory stridor, respiratory rate may be normal Restrictive respiratory pattern: Acute to chronic condition, normal to thin body condition score No respiratory noise +/- coelomic mass, +/- coelomic effusion An obstructive breathing pattern is associated with such conditions as a tracheal obstruction4,5,6 or syringeal mass (i.e. fungal granuloma). In these cases, placement of an air sac tube will help alleviate the dyspnea and allow the clinician to treat the inciting cause. If any coelomic effusion is present, regardless of the breathing pattern, air sac tube placement is contraindicated. Air sac tubes are placed in the caudal thoracic air sac or abdominal air sac using a similar approach as coelomic endoscopy.7 General anesthesia is necessary for placement. The clinician should select a tube of similar diameter to the patient’s trachea. I have used red rubber feeding tubes, endotracheal tubes, and air sac cannulas for this purpose. The patient is placed in right lateral recumbency, with the leg pulled cranially. The skin overlying the placement site is routinely prepped, and a small skin incision is made just ventral to the flexor cruris medialis muscle and caudal to the last rib. A pointed hemostat is used to create a defect in the coelomic wall with gentle downward pressure using a short finger stop on the instrument. The tube is secured routinely with a purse string suture followed by a Chinese finger trap suture. I then secure the tube on the bird’s dorsum to prevent self-trauma to the tube. An E-collar will likely be necessary to protect the integrity of the tube depending on the bird’s temperament. Whole body radiographs and confirmation of airflow through the tube will help determine if the air sac tube is in the correct location. Restrictive breathing patterns are seen for diseases of the small airways, lung parenchyma, and coelomic cavity disease, including effusion, masses, and/or organomegaly (Figure 2). Air sac cannulas will not help with these disease processes, and, further, may worsen the patient’s underlying condition. Air sac cannulas are absolutely contraindicated in cases of coelomic effusion. Oxygen therapy is essential and ideally administered to the patient in a quiet, incubator with heat support. Sedation with midazolam (1-3mg/kg IM, IN) and/or butorphanol (1-3mg/kg IM) is also indicated as an initial treatment if the patient is anxious or appears painful. When the patient is stable, additional diagnostics can be considered, including venipuncture for complete bloodwork, radiographs, or a coelomic ultrasound. The ‘fluffed’ bird Figure 3: A single dorsoventral whole body radiograph of a conure that presented for lethargy and other nonspecific signs of illness. There are several, small metallic foreign objects in the region of the ventriculus. Note the metallic microchip cranial to the foreign bodies. This bird was diagnosed with zinc toxicity and treated successfully with chelation therapy. One of the most common ER presentations of the avian patient is a “fluffed bird” or a bird at the bottom of the cage. Elevation of the feathers, giving a “fluffed” appearance helps to retain body heat and is a general sign of illness. Normally, most parrot species perch in the highest location possible; therefore, a bird that stays on the bottom of the cage is abnormal, and a general sign of illness. A complete physical exam and additional diagnostics are required to determine the etiology. A single, non-restrained dorsoventral whole body radiograph could be taken to check for the presence of metallic foreign bodies, which has the potential for heavy metal toxicity (Figure 3), or the presence of shelled egg(s). Two-view whole body radiographs often require sedation or general anesthesia for proper positioning in the psittacine patient. Depending on the case, it may be more appropriate to provide supportive care for 12 to 24 hours prior to sedation for diagnostics. An estimated white blood cell count and white blood cell differential can be performed in-house with a single drop of blood for a blood smear. A packed cell volume and total solids can also be performed in-house with a very small blood sample. For example, Abaxis produces an avian and reptile rotor that measures common biochemistry parameters of these species and requires a small volume (0.2-0.3mL) of whole blood. Fluid therapy is an important mainstay of generalized supportive care. The daily fluid requirement for most psittacines is 75-100mL/kg/day, which can be divided into twice daily treatments. Subcutaneous fluids are most commonly administered in the inguinal region, as sedation/anesthesia is often required for placement of IV or IO catheters. If the bird is able to stand, but is not eating on its own, gavage feeding a liquid diet for omnivores should be considered to help maintain their nutrient requirements. Their resting energy requirement (RER) can be calculated, but the clinician should also consider the crop volume of each patient to help determine how much of the liquid diet could be safely administered at one time. On average, the crop volume of a typical adult psittacine is 1mL/30 grams of body weight. If the bird is unable to stand or hold their head up, gavage feeding is contraindicated, as it can lead to regurgitation and aspiration.8 Cloacal prolapse Cloacal prolapse may involve the oviduct, intestines, or any portion of the cloaca. Prolapses can occur secondary to egg laying, excessive sexual/masturbatory behavior, constipation/tenesmus, or idiopathic/behavioral (especially in male cockatoos). Cloacitis, cloacaliths, severe enteritis, or GI obstruction have all been documented as causes for cloacal prolapse secondary to tenesmus. Ideally, the primary cause of the cloacal prolapse should be identified and corrected in addition to replacement of the cloacal tissue, if still viable. Once the viable prolapsed tissue is replaced, two lateral full-thickness sutures can be placed in the vent as a temporary solution, but recurrent prolapses may require more permanent surgical fixation including ventplasty, cloacopexy, or salpingectomy (if the oviduct is affected). Purse string sutures should never be placed in the cloaca of birds, as constipation and inability to pass droppings often results from the too narrow vent opening. Olivia A. Petritz, DVM, DACZM, graduated from Purdue University, and then completed several internships and a residency in the field of zoo and exotic animal medicine. She became a diplomate in the American College of Zoological Medicine in 2013 and specializes in zoological companion animals (exotic pets). She started an exotics service at a specialty hospital in Los Angeles following her residency, and currently is an assistant professor of avian and exotic animal medicine at North Carolina State University. References 1 Gildersleeve, R. P., et al. “Hematological response of Japanese Quail to acute hemorrhagic stress.” Comparative biochemistry and physiology. A, Comparative physiology 81.2 1985; 403-409. 2 Schindler, S. L., et al. “Blood volume recovery in hemorrhaged Japanese quail.” Comparative biochemistry and physiology. A, Comparative physiology 88.1 1987; 95-100. 3 Orosz SE, Lichtenberger M. Avian respiratory distress: etiology, diagnosis, and treatment. Vet Clin North Am Exot Anim Pract. 2011;14(2):241-255. 4 de Matos REC, Morrisey JK, Steffey M. Postintubation tracheal stenosis in a Blue and Gold macaw (Ara ararauna) resolved with tracheal resection and anastomosis. J Avian Med and Surg. 2006;20:167-174. 5 Guzman DS-M, Mitchell M, Hedlund CS, Walden M, Tully TN. Tracheal resection and anastomosis in a mallard duck (Anas platyrhynchos) with traumatic segmental tracheal collapse. J Avian Med and Surg. 2007;21:150-157. 6 Sykes JM, Neiffer D, Terrell S, Powell DM, Newton A. Review of 23 cases of postintubation tracheal obstructions in birds. J Zoo Wild Med. 2013;44:700-713. 7 Brown,C., and Pilny A. “Air sac cannula placement in birds. “Lab animal 35.7. 2006; 23-24. 8 Stout, JD. “Common emergencies in pet birds.” Veterinary Clinics: Exotic Animal Practice 19.2. 2016; 513-541.
