Emergency and Critical Care of Avian Patients
World Small Animal Veterinary Association World Congress Proceedings, 2013
Laurel Degernes, DVM, MPH, DABVP (Avian)
College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Avian emergency presentations range from decompensated sick birds, trauma, and toxins, to birds with respiratory or reproductive tract diseases. The underlying physiologic and pathologic problems must be quickly identified and treated using diagnostic and treatment approaches tailored to the individual patient. However, a generic approach to supportive care and antimicrobial therapy may be used until a specific diagnosis is made.

"Sick Bird Symptoms"

Birds are masters at hiding clinical signs of illness, which is a survival strategy to avoid being "picked off" by predators and/or ostracized from the flock. Subtle signs of "sick bird symptoms" (SBS) must be quickly recognized and acted upon, since sick birds can quickly progress to dead birds without appropriate and timely intervention. Many signs of illness are non-specific for any one disease problem, and can include any changes in behavior (increased sleeping, decreased activity, fluffed feathers, sitting on bottom of cage), decreased or changed vocalization, changes in appetite (selective appetite to anorexia), reduced or abnormal droppings, vomiting, dyspnea or wheezing, etc.2-5

When an owner calls late on a Friday afternoon reporting that her parrot is sitting fluffed on the floor of its cage, she should be advised to bring her bird in immediately for emergency care. Even under the best of circumstances and in the most qualified clinician's hands, some of these patients are presented too late to save the bird (therefore, the owner is always warned about possible death during initial or subsequent handling and treatment of these critical patients).

When the owner arrives, be prepared to stop hemorrhage if bleeding is occurring and place the bird in a quiet, heated cage (with oxygen if indicated) while the history is taken and a plan is developed for diagnostic and treatment options. Important questions in this history include the onset and progression of illness/problem, whether or not other birds are sick, whether there are any new birds in the household or exposure to other birds, and if there is any known toxin exposure (any unsupervised time outside the cage?).

Trauma

Common causes for an emergency presentation of a bleeding bird include broken blood feather, broken toe nail or tip of beak, self-mutilation, and various traumatic injuries (i.e., cat bites, fractures or soft tissue injuries from collisions, etc.). Pulling the broken blood feather using a hemostat, and applying direct pressure to the base of the follicle, is generally effective. Direct pressure to control hemorrhage, wound management, bandaging and supportive care are indicated for other injuries. Any confirmed or suspected cat bite injury should be flushed and the bird placed on broad spectrum antibiotics immediately.

Additional treatments including surgery may be indicated for some types of injuries, particularly orthopedic emergencies, although surgery is generally delayed until the patient is stabilized.

"Decompensated" Patient Emergency

Many different diseases can have a similar, non-specific emergency sick bird presentation, including gram-negative bacterial infections, chlamydiosis, aspergillosis, heavy metal toxicosis (lead or zinc), hepatic lipidosis, and some female reproductive tract diseases. Every effort should be made to stabilize the bird, even if diagnostic sample collection is postponed until later (better to have a live bird and no CBC, than...). Diagnostic and treatment options are discussed at the end of this article, since many of these options apply to a wide spectrum of avian emergencies.

Respiratory

Respiratory emergencies can be caused by partial tracheal/syringeal or bronchial obstructions due to an inhaled foreign body or localized granuloma formation (i.e., aspergillosis). The patient should be temporarily placed in an oxygen cage while supplies for an emergency airsac cannula are set up. The airsac cannula provides alternate access for unobstructed breathing while the foreign body or granuloma is removed and treated if possible. Other respiratory emergencies may be secondary to inhaled toxins. Birds are exquisitely sensitive to inhaled toxins, particularly from overheated Teflon (polytetrafluoroethylene gas) products such as non-stick cookware, self-cleaning ovens, and certain stain-retardant products applied to upholstery and carpeting. Teflon exposure can cause severe pulmonary hemorrhage and rapid death. Other potential causes of inhaled respiratory toxins include air fresheners, paint fumes, scented candles, and many other household aerosols. Specific treatments and antidotes are usually not available, and the prognosis for successful treatment is poor (especially for Teflon toxicosis). These birds should be placed in an oxygen cage, and started on anti-inflammatory drugs, antibiotics and provided supportive care.

Reproductive Tract Emergencies

Egg binding is one of the most common reproductive tract emergencies, and can be secondary to excessive egg size, poor nutrition for the hen, infections (of the oviduct or elsewhere), dehydration, hypothermia, etc. Clinical signs can include straining, dyspnea, abdominal swelling, and in advanced cases, unilateral or bilateral leg paresis and death. These patients should be stabilized in a heated cage, and provided warmed fluids, calcium injection, and intra-cloacal infusion of warmed water-soluble gel. Manual delivery may be successful in some cases, or ovocentesis can be used on an anesthetized patient (large needle placed into the partially exteriorized egg shell to aspirate part of the liquid contents, followed by gentle "implosion" and manual delivery of shell pieces). A caesarean section or salpingohysterectomy can be considered if other methods fail, but these surgical procedures are more complicated in avian patients.

Heavy Metal Toxicosis

Ingestion of lead or zinc particles can lead to acute toxicosis in parrots. A history of exposure can be useful, but the absence of known exposure does not preclude the possibility of ingestion. These birds usually present with "SBS" that often includes vomiting and passage of green-tinged urine/urates. Diagnostic evaluation should include at a minimum, a CBC, heavy metal screen for Pb/Zn, and radiographs. Radiographic evidence of metal fragments in the ventriculus can support a suspicion of heavy metal toxicosis, but it is important to remember that any type of metal will have a similar opacity on radiographs, and the absence of metal in the GI tract does not rule out heavy metal toxicosis. Supportive care should include fluids, nutritional support, and chelation (+/- antibiotics if indicated) until diagnostic test results are available. Conservative options for metal fragment removal include endoscopy or oral administration of bulk laxatives (psillium) or peanut butter.

Diagnostic Options

Diagnostic options, when indicated and when possible to perform, can include a CBC and biochemistry profile, fecal Gram stain, cloacal culture, heavy metal screen, specific disease diagnostics (i.e., Chlamydophila PCR), and radiographs. Keep in mind that it is advisable to collect only 0.5–0.75% of a bird's body weight in blood from sick or debilitated birds, and up to 1% of a bird's body weight from otherwise healthy birds. Fortunately, many of the bench top chemistry analyzers require small amounts of blood (~ 0.1 ml). More details about various diagnostic test options were reviewed in Avian Medicine 101, a separate article by this author.

Treatment Options

Specific and generic treatments should correct hypothermia, dehydration, hypovolemia, anorexia/malnutrition, septicemia, and/or heavy metal toxicosis.1 Treatments should be prepared prior to handling the bird to minimize the stress of handling. Most importantly, a critically ill or injured parrot should be stabilized first, using fluid therapy, heat (+/- oxygen), nutritional support, antimicrobial therapy, and chelation therapy, as indicated. Warmed crystalloids (saline or LRS) administered intravenous (IV), intraosseous (IO), subcutaneous (SQ), and/or oral, should be administered at a rate of 50 ml/kg/day for maintenance and approximately 50 ml/kg/day for fluid replacement (assuming that the patient is ~ 7–10% dehydrated), for a total daily volume of 100 ml/kg. IV and IO catheters can be maintained for 48–72 hours, but must be protected with bandaging from most parrots. Optimal fluid therapy is done via continuous rate infusion, however, parrots may bite the IV fluid line. Fluid treatments are generally divided into 2–3 daily treatments, and administered as a bolus, at 10–20 ml/kg at one time (maximum IV or IO fluid volume at one time). The remainder of the fluid requirements is administered via oral and SQ routes. Colloids such as hetastarch, can be used in birds, as well as homologous blood transfusions if needed. Nutritional support using oral gavaged tube feeding formula (such as commercially available products specific for avian critical care) can be given at an approximate rate of 30 ml/kg, for 2–3 treatments per day. Birds should not be handled for at least 3–4 hours following tube feeding, to avoid iatrogenic regurgitation and aspiration. Antibiotic agents for possible bacterial infection should always be initiated for sick birds with an undiagnosed illness, while diagnostic test information is pending. Unlike with mammals we never wait to start antibiotics with birds since there is little time to waste! If a gram-negative bacterial infection is suspected, enrofloxacin at 25 mg/kg once daily SQ in the SQ fluid "pocket" should be started. Chlamydophila suspects should be started on doxycycline. Terbinafine, itraconazole or voriconazole can be considered for aspergillosis suspects. Calcium EDTA or dimercaptosuccinic acid (DMSA) should be initiated for possible lead or zinc poisoned birds. Under almost no circumstances should steroids be used, particularly long-acting or multiple doses. Generic treatments are often initiated before the clinician has any definitive information about the underlying disease or problem. The treatment options can always be modified based upon new diagnostic information or response (or lack thereof) to treatments. It's also possible that an emergency patient will respond to the generic treatments and a definitive diagnosis is never made.

References

1.  Carpenter J. Exotic Animal Formulary. 4th ed. Philadelphia, PA: Elsevier; 2012.

2.  Harcourt-Brown N, Chitty J, eds. BSAVA Manual of Psittacine Birds. Quedgeley, Gloucester, UK: British Small Animal Veterinary Association; 2005.

3.  Harrison G, Lightfoot T. Clinical Avian Medicine I, II. Palm Beach, FL: Spix Publishing; 2006.

4.  Samour J. Avian Medicine. 2nd ed. Philadelphia, PA: Mosby/Elsevier; 2008.

5.  Tully TN, Dorrestein GM, Jones AK. Handbook of Avian Medicine. 2nd ed. Philadelphia, PA: Saunders/Elsevier; 2009.

  

Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

Laurel Degernes, DVM, MPH, DABVP (Avian)
College of Veterinary Medicine
North Carolina State University
Raleigh, NC, USA


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