Preliminary Evaluation

When a critically ill bird is presented, the initial task is to determine whether or not the patient is stable in order to gauge its ability to withstand physical examination. The mechanics of obtaining lab samples or administering treatment seem relatively easy; keeping the patient alive during those procedures is not. The scenario where the "healthy" canary dies in the hands of the examiner during a routine exam is all too familiar; the chances of the patient dying unexpectedly are much greater when the patient is ill. The level of risk directly correlates with the degree of illness. In some situations, the bird may require immediate transfer into an intensive care unit to revive or stabilize its condition. These birds cannot tolerate manipulation. It is a practitioner's primary responsibility to assess, "How much is too much?" with regard to critical patients.

The technique of ascertaining the patient's stability involves obtaining meaningful information from the owner and observing the bird as presented. The history may reveal the period of time and the manner in which the problem evolved. Although it may seem that a chronically ill bird might be closer to the end than an acutely ill patient, the opposite is often true. Birds that display signs of illness for several days to weeks often compensate for their disease and consequently become stable. Those that develop serious clinical signs acutely may be very decompensated. The history must be taken carefully and specific questions asked; examine the owner's account of the onset and duration of signs. Knowing the client may be helpful in deciphering the information. "He was fine yesterday" is only as legitimate as the client is knowledgeable and/or perceptive. It may become evident that the owner is not knowledgeable enough, or has not observed the bird closely enough, to know when the illness (or at least its clinical signs) started. On the other hand, a diligent client who is faithful to the bird's needs may provide a very accurate history. Whenever uncertainty exists, it's best to be cautious.

Whatever background information the client provides, the clinician must observe the patient before attempting to handle him. This practice may seem straightforward, but it cannot be overemphasized that the bird's life may depend on this "hands off" assessment. A thorough step-by-step visual exam provides preliminary information that minimizes the chances of unexpected deaths.

When the situation permits, the bird should be observed from a distance. A bird will often appear more alert and responsive when approached, giving the illusion of wellness. Observations made from a distance more accurately reveal the bird's condition. A resting bird that displays open-mouthed breathing, tail-bobbing, closed eyes, and ruffling of the feathers will tolerate little (if any) stress. The same bird may perk up and seem less critical when examined closely. The distant behavior in such a case warns the clinician to proceed with caution. The bird that brightens when approached may be stronger than one that continues to show significant signs, but a false sense of security may exist in an examiner who fails to realize how well a bird disguises its signs of disease.

Once the bird has been observed from a distance, it may be examined more closely. Attention should be paid to the bird's response upon the clinician's approach. Some birds may instantly react, while others must be provoked before responding. Obviously, a bird which hops down to the bottom of the cage when approached is more stable than one that falls to the bottom. Circle the cage; a bird that does not suspiciously follow your movements is not reacting normally, and may not have the strength to do so. As the bird is observed, details will be noted which reveal more about its condition and stability. The eyes may be open or closed, the corneas clear or dull. Nostrils may be crusted over, restricting the airway, or completely unaffected. Respiratory motions may be normal or labored, with pronounced tail-bobbing and respiratory sounds potentially audible without a stethoscope.

Posture may be erect or the bird may squat on the perch, conserving what little energy remains. Looking at the shape or contour of the bird's body can reveal weight loss, abdominal distension, etc. When all information has been collected from observation, the clinician must decide whether he should: a) place the bird in a supportive intensive care chamber in hopes of reviving its health before further action, b) directly administer basic supportive treatment before proceeding, or c) perform the physical exam with or without collecting diagnostic samples. Experience will fine-tune the clinician's ability to determine which route to follow.

Medical Management

Before handling the bird for any reason, a detailed plan based on findings of preliminary observations must be formulated. This plan must account for all the diagnostic and therapeutic actions warranted by the patient's condition while identifying the degree to which the bird is expected to tolerate handling. More delicate patients require greater care in handling. These birds, however, are the ones that need the most support. A difficult situation then exists, in which the patient needing the most help is the one least capable of tolerating stress. The key to managing these birds is conservative progression - gently performing one maneuver at a time, prioritized relative to estimated needs, then waiting for the clinical effect before proceeding. It is imperative that every detail of the diagnostic/therapeutic plan be anticipated and accounted for beforehand. It could be fatal to remember a necessary item after the process has begun.

Specific supportive measures depend on actual needs; these needs may only be estimated in critical patients without background clinical data. However, general techniques can be employed on almost any critical patient which consistently provide some degree of clinical stabilization. Upon presentation, the majority of critical cases will be suffering from dehydration and hypothermia. Birds that are collapsed on the bottom of the cage, and/or have been ill for a long period of time, are probably severely dehydrated and hypothermic. A bird that collapsed within the previous hour or so may not suffer from either condition. An astute impression can be gained during preliminary observations. Dehydration can be assessed by closely observing the eyes and skin of the face and feet. The eyes may appear dull and dry, while the skin of the lower legs and feet may appear discolored, withered and wrinkled. A bird that is fluffed and trembling on the perch or huddled on the cage bottom can be presumed to be hypothermic. If these conditions are considered, they can be further evaluated when the patient is eventually handled. By anticipating the need to treat, therapy can be administered immediately if the requirement is confirmed.

Initial Handling

After the bird is visually examined, he may be removed from the original cage/carrier so that his status can be reevaluated. At this time, the clinician should be keenly attentive to the behavior of the bird. Any evidence of distress should prompt immediate release of the bird into a suitable intensive care unit. The physical exam at this point should focus on indicators of the patient's hydration, thermal condition, etc. In many situations, it will be necessary to treat dehydration and hypothermia prior to further manipulations. If the patient appears stable, the examination may proceed to the taking of samples for selected diagnostics. The veterinarian should be careful not to over-handle the bird.

In general, any bird presented in critical condition due to illness (as opposed to injury) can be presumed to be at least 10% dehydrated and acidotic; those that have been vomiting may be alkalotic. A bird that is 5% dehydrated will demonstrate brief tenting of the skin over the tarso-metatarsus, face, or between the shoulders, dryness of the eyes, and a dullness to the skin; at 10% dehydration the patient will show persistent tenting, mild hypothermia, and thick oral secretions; 15% dehydration will lead to the above signs plus profound weakness, tachycardia, and collapse.

A hypothermic bird will have a cold beak and feet, and often feels noticeably cool when handled. Circulatory condition can be assessed by observing the basilic (median ulnar vein) as it crosses the ventral elbow. Circulatory collapse will be indicated by slower refilling of this vein after digital compression. Use of warmed IV fluids and a heated intensive care unit will simultaneously elevate core and peripheral body temperature efficiently. Peripheral vasodilation from external heat may exacerbate the hypovolemia, further lowering body core temperature, and may aggravate acidosis if it exists. It is important that the hypothermia is not attended to without recognition of the fluid needs.

Fluids containing glucose may be of great benefit in anorexic patients. Fluid therapy is discussed at length elsewhere in this publication, including guidelines for calculating fluid volumes and compositions. In avian patients, IV fluids may be administered as a bolus at the fastest rate the needle will allow. The syringe and fluids should be warmed to a temperature approximating body temperature (100°F) prior to administration. The fluids may be administered via the jugular, basilic, or medial metatarsal veins, or through an intraosseous catheter. If the patient is significantly dehydrated, oral or subcuticular fluids may not be beneficial. Intraperitoneal fluids are not advised, and may be hazardous due to the risk of fluids entering the air sac system.

The addition of medications such as antibiotics or steroids to the fluids may be indicated. In situations where the patient is possibly septic or in shock, the use of steroids may be indicated as discussed elsewhere in this volume. If bacterial sepsis is suspected, antibiotics may be given directly IV or via IV fluids. When adding drugs to the fluids, incompatibilities should be avoided.

Once fluids have been administered, the patient may be placed in an intensive care unit which ideally can supply heat, humidity, and oxygen. Many commercial units are designed to provide heat and oxygen, without regard to humidity. In the author's experience, warm, moist air appears to safely and effectively reverse hypothermia, possibly because of its effect of reducing evaporation from the extensive internal respiratory surface area. Also, the drying tendency of oxygen, when used, is nullified. In the author's practice, the best method of providing heat and humidity has been to place a pan of hot water covered by a rubber grill inside the intensive care unit. The bird is placed on the grill, allowing the mild steam to envelop its body. Monitoring the hypothermia is mostly a matter of clinical perception. The average adult bird has a core body temperature of 38–42°C (100.6–112°F), but monitoring this directly can add stress and even be dangerous if the patient is fractious or if a rigid thermometer is not handled carefully. Overheating (as evidenced by panting) can become a problem if the patient is not monitored closely while in the chamber.

The administration of oxygen is often beneficial and rarely contraindicated. A critical patient, especially one in shock, may suffer from diminished cardiac output. Providing oxygen maximizes the efficiency of the cardio-respiratory system. If the bird is dyspneic for any reason, oxygen is recommended. Over-oxygenating the patient prior to handling may also decrease the risks of handling.

A critically ill bird handled in the described manner will often show clinical improvement within a short period of time, sometimes less than an hour. At this time, the clinician may choose to further examine the bird, collect diagnostic samples, or implement further therapy.

Conclusion

The goal of supportive therapy centers on stabilizing the patient until specific therapy can be established. Initially, therapy aims toward correcting fluid deficits and hypothermia. As the diagnosis is delineated, treatment becomes more focused. Supportive care may be withdrawn after the patient demonstrates a satisfactory degree of self-sufficiency. Successful management means providing aggressive support carefully - one step at a time. A keen awareness of the patient's tolerance for stress prevents him from being handled to death.