Performing an Avian Physical Examination in Practice

It is a common misconception that avian patients are fragile animals that are not resistant to disease, which leads to a fear of them dying during physical examination. Healthy birds are actually quite hardy; however, as prey species, birds are adept at hiding signs of illness, even from human family members who care for them. As a consequence, many birds presenting to veterinarians are in more severe states of disease than small animals and are often decompensated. The ability to perform an avian physical examination or, in sick birds, a triage examination in a timely manner is therefore vital (BOX 1). This process starts with a distant examination.

Distant Avian Examination

Evaluating a bird from a distance before restraining it for a full physical examination can be a powerful tool. It takes practice to recognize a bird that is attempting to hide illness; however, subtle changes in behavior and appearance can suggest a problem.

Evaluate whether the bird is bright, alert, and responsive. Some avian species, such as parrots and chickens, will be vocal, which is normal.

Observe the bird’s body posture, as well as respiratory rate and effort. A healthy bird should hold its head up and be looking around the room. “Sick bird posture” is typically characterized by a bird being fluffed up, having its eyes closed, sitting at the bottom of the cage, tucking its head to one side or the other, and being lethargic. Some sick birds may even sleep while in the examination room.

Watch the bird moving around its cage or, with species such as chickens and waterfowl, walking around the room to check mobility.

Also evaluate the droppings, if they are available, and collect them in case they are needed for diagnostic testing following the physical examination (FIGURE 1).

Figure 1. Normal chicken droppings. Note the well-formed feces and the presence of white urates. A small amount of urine can also be present and often forms a ring around the other components of the droppings. Parrot droppings appear similar but less voluminous.

Avian Handling and Restraint

Safe handling involves safety for both the handler and the bird. As the handler, it is important to recognize the defensive mechanisms of the type of bird being handled. For all avian species, the first instinct is to escape (VIDEO 1). However, many companion birds have learned to trust humans and may not be as apt to try to escape when captured and handled.

Handling Parrots

Many parrots are best handled with a towel or cloth to prevent development of a fear of hands. Towels can also be used to aid in restraining the wings and pelvic limbs. Use caution when handling parrots, as their strong beak can inflict a painful bite.

Gently and slowly envelop the parrot in a towel while talking in a friendly, calm manner (VIDEO 2). With the towel, the handler can hold the bird’s head firmly at the base of the mandible or around the neck with 1 hand (FIGURE 2). The other hand can hold and control the feet while the bird’s body rests in the palm of the hand or along the forearm, depending upon the size of the bird.

Figure 2. Correct restraint of a parrotlet for a physical examination. Note the use of a towel to assist in wing restraint.

In some cases, use of sedation can be beneficial for physical examination and minimally invasive diagnostic testing, such as blood collection, radiography, and ultrasonography. Sedation can be performed using a traditional intramuscular route or can be administered intranasally (VIDEO 3). As birds look different when sedated, it may take time to develop a comfort level with what to expect with regard to muscle tone and other physical parameters (VIDEO 4). Information about sedation can be found elsewhere in the literature.¹

Handling Chickens

Most chickens are amenable to manual restraint. To reduce the chance of trauma to themselves, the handler can first restrain the wings close to the body, as chickens often flap. Once the wings are restrained, the handler can gently pick up the chicken with two hands and hold the bird close to their body. When the chicken is on an examination table, putting the feet on a solid, nonslippery surface with the wings held to the bird’s sides is often effective (FIGURE 3). Covering the head using a towel or a stockinette has also been shown to decrease stress in this species.²

Figure 3. Correct restraint of a chicken for examination with the wings held gently against the body.

Chickens should never be held upside down by the pelvic limbs, as this position can lead to injuries, regurgitation with possible aspiration, and stress for the bird. They also should not be restrained by the wings, which can lead to injuries from the bird’s weight being supported by such a small body part.

Hands-On Avian Examination

Once the bird is in hand, monitor its mentation, response to stimuli, and behavior throughout the physical examination and restraint period. If open-mouth breathing, excessive struggling or vocalization, or decreases in muscle tone are noted, the bird should be released from handling.

Care must be taken to avoid compressing the sternum during handling. Birds lack a diaphragm, and compressing the sternum prevents effective ventilation; therefore, the sternum must be allowed to move freely.

During palpation, be aware that birds do not have lymph nodes. A general, brief neurologic examination should be performed with each physical examination.³ While moving through the physical examination, note the cranial nerves and appreciate reflexes, motor responses, and sensory responses (VIDEO 5).

Body Weight and Body Condition Score

Both body weight and a body condition score should be obtained during the physical examination. Pairing these measurements is important and allows for tracking trends over time.

Most adult chickens will stand readily on a tabletop baby scale that weighs in grams. Some may be large enough to stand on a floor scale designed for dogs. For medium or large psittacines, it is simplest to weigh the carrier while the bird is in it and then subtract the weight of the carrier while the bird is in hand. For small psittacines, using a gram scale is advantageous.

Body condition scoring is subjective but becomes more accurate and precise with repetition. Either a 5-point or 9-point scale may be used as long as it is consistent within the practice. To assess body condition, palpate over the keel for the pectoral musculature. In some birds, such as chickens, also palpate along the sides of the body over the ribs and up into the axillae for fat deposits. Chickens also deposit large amounts of fat in the caudal coelom.

A 9-point scale considering the pectorals is as follows:

• 1 indicates poor condition with very concave muscles.
• 4 indicates fair condition; in these birds, the musculature is slightly concave.
• 5 is considered ideal and reflects musculature that is symmetrically rounded over either side of the keel.
• 6 to 7 is given for slightly convex musculature and indicates some extra weight.
• 9 reflects a very convex shape and indicates obesity.

A client who handles their bird regularly may recognize a low body condition score as the first sign of illness and may state that the keel feels “sharp.”

Eyes

Assess the position of the eyelids first (FIGURE 4). A healthy bird should have the lids open, whereas a potentially sick animal may keep the eyelids partially or fully closed. Ocular lesions or pain may present as blepharospasm, similar to mammals.

Figure 4. Performing a direct ophthalmic examination in a parrotlet. Note the hand and instrument positioning to allow for examination of the small eyes.

Evaluate for evidence of ocular discharge, including any wet, matted, or crusted periorbital feathers. The surface of the cornea should be relatively flat, moist, and shiny.

The anterior chamber of the eye should be clear and the third eyelid, or nictitating membrane, should be smooth as it sweeps over the cornea. Evaluate the lens for any evidence of lenticular sclerosis, cataracts, or inappropriate shifting (i.e., posterior or anterior luxation). The sinuses, located ventral to the orbit, should be flat and free of swelling.

When evaluating the retina, note that birds have an anangiotic, or avascular, fundus. The pecten, which most often looks like a thick brown structure in the ventral region of the fundus, should also be evaluated.

External Auditory Canals

This is one of the most overlooked parts of the avian physical exam. To evaluate the external auditory canals (ears), gently retract the feathers and skin surrounding the opening (FIGURE 5). Evaluate both sides for symmetry and healthy-appearing skin within the canal. Typically, an otoscope is not needed to evaluate the aural canal; however, if further evaluation is needed, anesthesia to facilitate a deep otoscope or thin rigid endoscopy examination is advantageous.

Figure 5. Performing an otic examination in a parrotlet. This is the normal appearance for parrot ears. There should be no crusting, debris, erythema, or masses.

Nares, Cere, and Beak

The nares are located in the proximal area of the rhinotheca, or the maxillary beak, in the region of the cere. The nares should be symmetric, clean, and clear bilaterally. The gnathotheca, or mandibular beak, and the rhinotheca should fit together to allow the bird to close its mouth. Evaluate for any evidence of excessive keratin layering, flaking, or malocclusion.

Oral Cavity

The mouth may be opened manually using various techniques, depending on the species. One-inch white tape folded lengthwise to create half-inch strips may be used for medium to large parrots (FIGURES 6 AND 7). For small parrots, paper clips can be used to open the beak; however, take caution not to damage the keratin (FIGURE 8). In chickens, put gentle digital pressure at the commissures of the mouth and carefully depress the gnathotheca. A light source, such as a transilluminator, is very helpful when evaluating the oral cavity, as the caudal structures are relatively deep in some species, such as chickens.

Figure 6. Normal appearance of the oral cavity in an eclectus parrot. Note the pigmentation within the oral cavity and on the tongue, which is common in many species, as well as the presence of the glottis at the base of the tongue and the lack of an epiglottis, which is normal. Also note the use of white tape strips to restrain the beak in an open position without damaging it.

Figure 7. Normal, sharp choanal papillae in a monk parakeet. Again, white tape strips are used to restrain the beak in an open position without damaging it.

Figure 8. Blunted choanal papillae caused by hypovitaminosis A in a cockatiel. Care must be taken when using paper clips to restrain the beak in smaller species, as there is a risk of damaging the keratin with this method.

The mucous membranes should be pink and moist. Dry, stringy saliva may indicate dehydration, but note that birds do not have as much saliva in their mouths as dogs and cats do. The oral cavity should be clean and free of lesions or debris. Evaluate the caudal oropharynx carefully and look at the opening to the glottis, which should also be clean and free of lesions. The choana—the cleft that connects the nasal passages to the oral cavity—is found on the roof of the mouth. This area should be clear, and there should be symmetrically sharp choanal papillae bilaterally (FIGURE 7). Blunted papillae can suggest an underlying nutritional issue, such as hypovitaminosis A (FIGURE 8). Evaluate the tongue for lesions or masses, and look under it as well.

Comb (Chickens)

The comb should be an even red color, except in heavily pigmented breeds, which may have a variety of colorations. Normally, the comb should be upright, but over time it may deviate to one side. As long as this is not an acute change, it is considered normal.

The comb may be digitally blanched to assess the capillary refill time. A normal comb should refill in 2 seconds or less. Color change or lesions of the comb may indicate an underlying disease condition. For example, a blue/purple/gray/dark red color may indicate cyanosis and inadequate oxygenation or cardiovascular compromise; paleness may represent numerous conditions, including anemia, molting, heat stress, or dystocia.

Crop

After evaluating all structures of the head, move down to palpate the cervical structures, most importantly the crop. Depending on the species, the crop may be large or small. In parrots, the crop should be soft and may contain food material, depending on when the bird last ate. If the bird has been fasted, the normal crop should be empty. In chickens, the crop is normally larger than in parrots, may contain food material, and may be somewhat pendulous (like a moist bean bag). The crop has peristaltic movement, and rates of emptying vary by species. In most parrot species, the crop empties rapidly—within a few minutes in some smaller birds, and within a couple of hours in larger birds. In chickens, the crop should empty within a few hours. It is abnormal for the crop to feel “liquidy” or “doughy” or to have a sour or yeasty odor. It is also abnormal for the crop to fail to empty.

Heart

All birds have a 4-chambered heart, similar to mammals. To auscultate the heart, place the stethoscope over either side of the keel and listen to both the right and left sides. A heart rate should be obtained. Heart rates vary by species, with smaller birds having faster rates than larger birds. Heart murmurs and arrhythmias are possible to auscultate but require a keen ear and a quiet room due to the relatively fast heart rate of most species.

Lungs and Air Sacs

Birds have complete cartilaginous tracheal rings, a syrinx (where vocalizations are produced), and 2 lungs firmly attached to the dorsal body wall and ribs. In general, birds have 9 air sacs, including paired cervical, cranial thoracic, caudal thoracic, and abdominal air sacs, and a single clavicular air sac. Air sacs are not involved with gas exchange but do connect to the lungs and pneumatic bones, including the humerus and femur.

To auscultate the lungs, place the stethoscope over the dorsum between the wings. There should be minimal sound present. To listen to the air sacs, auscultate on the ventrum, just caudal to the sternum, on both sides. There should be minimal sound present.

A respiratory rate should be obtained and will vary by species. Observe the bird for signs of open-mouth breathing, tachypnea, or dyspnea. In sick birds, dyspnea is frequently accompanied by other signs, including tail pumping. If tail pumping is seen, respiratory compromise needs to be considered.

Keel

The keel is attached to the sternum of the bird and serves as a point of attachment for the large pectoral muscles. Its movement is required for breathing. The keel should be straight, and deviations may indicate acute or chronic trauma. Between the crop and the keel, you may palpate the furcula (clavicle or “wishbone”), which should be V-shaped.⁴

Wings

When evaluating the wings, it is important to support the entire wing at each joint to prevent accidental trauma. Extend each wing individually and put each joint through passive range of motion as it is palpated. Evaluate hydration by identifying the ulnar vein, also known as the basilic or wing vein, which may be found by using a moistened cotton ball to part the feathers over the ventral elbow. The vessel may be blanched using digital pressure; it should have almost instant refill (visualizing the refill should not be possible because it is so fast) in a normally hydrated bird (VIDEO 6). Any delay is suggestive of hypoperfusion/hypovolemia (VIDEO 6).

Coelom

Birds have a coelom, as they lack a diaphragm to separate the thoracic and abdominal cavities. The sternum and keel are large in most avian species, which limits palpation of the coelomic structures.

Cranially, the organs will be covered by the sternum and will not be palpable. In the normal bird, this includes the heart, lungs, esophagus, proventriculus, and liver. The liver should not be felt beyond the caudal border of the keel. Caudally, there is a palpable area of the coelomic space between the caudal end of the sternum and the pubic bones of the pelvis. Organs in this space include the ventriculus; the remainder of the gastrointestinal tract; and the spleen, pancreas, reproductive organs, adrenal glands, and kidneys. Palpable structures may include the ventriculus in the left cranial portion of the coelom and, in females, the oviduct on the left if it is enlarged or if there is an egg present.

Overall, in parrot species the coelom should be concave and few to no structures should be palpable (FIGURE 9). In chickens, the coelom is often convex, especially in egg-laying birds. Eggs may be palpable, which can be mistaken for the ventriculus in some cases. Coelomic palpation is key to assessing for ascites, organomegaly, or masses.

Figure 9. Coelomic palpation in a parrotlet. The coelomic cavity should be concave, and the pubic bones should be easily felt at the caudal aspect, near the vent.

Pelvic Limbs and Feet

To evaluate the pelvic limbs, palpate each joint, including the coxofemoral joint, stifle, tarsus/hock, and digits, and put the joint through passive range of motion. Each joint should move smoothly in both flexion and extension and be free of crepitus. Palpate the musculature of the limbs for symmetry. Evaluate the nonfeathered skin of the lower limbs for scaling and lesions. The nails should be straight and at a comfortable length for the bird to walk.

Carefully evaluate the feet, as many species, such as chickens, are prone to pododermatitis or “bumblefoot” (FIGURE 10). Check each toe individually on the dorsal and plantar aspects as well as the central metatarsal pad. Evaluate for erythema, flattening of the plantar papillae, fissures (often associated with interphalangeal joints), ulcers, and fibrosis. In acute cases with fresh lesions, and in chronic or severe cases with large lesions, the bird’s mobility and comfort may be affected.

Figure 10. Pododermatitis in a chicken. (A) Dorsal view. Note the appreciable swelling on the dorsal and lateral sides of the feet.

Figure 10B. Plantar view of the same chicken. This is an example of grade 4 (out of 5) pododermatitis.

If pododermatitis is noted, use a 1 to 5 grading scale to document it and promote consistency within the practice. Photos or a detailed drawing in the bird’s medical record can be helpful to track trends over time, as cases may require long-term management.

• Grade 1 (mild) indicates flattening of the skin or blunting of the plantar papillae, some erythema or shininess of the skin surface, but no evidence of infection.
• Grade 2 indicates infection surrounding a superficial lesion.
• Grade 3 indicates abscess formation with serous or caseous fluid draining from a fibrotic lesion.
• Grade 4 indicates a chronic infection with swelling of deeper tissues, which may include comorbidities such as arthritis or osteomyelitis.
• Grade 5 (severe) indicates infection with swelling, possible comorbidities with severe loss of comfort and function, and radiographic changes to the underlying bones.

Feathers and Skin

During the physical examination, take note of overall feather quality and condition. A healthy bird should have smooth, shiny, well-preened feathers. Birds going through molt may have feather loss and may also have new feathers growing in, called blood feathers, on the wings (remiges), tail (rectrices), or over the body. Molting feathers are different from traumatized or barbered feathers, which may have split shafts, be uniformly short, or be associated with dermatitis (FIGURE 11).

Figure 11. Feather-destructive behavior in a grey parrot. Note the presence of the tattered and destroyed feathers, as well as a blood feather.

If there are areas of absent feathers on the body, note the location. If they are on the head and dorsal neck (i.e., somewhere the bird cannot reach itself), consider trauma from other birds, if present. Stress bars are areas where the feather was weakened while it grew, usually by physical or nutritional stress; if present, these should be noted (FIGURE 12). Missing feathers around the vent with pain and irritation in the region is common in chickens and may be seen with reproductive issues.

Figure 12. Stress bars on feathers due to a previous traumatic event.

Vent

The vent, which is the external opening of the cloaca, should be evaluated. The cloaca is the communal chamber of the digestive tract (coprodeum), urinary tract (urodeum), and reproductive tract (proctodeum). The vent should display adequate tone. The vent and surrounding feathers should be dry and free of urates or feces.

Uropygial Gland

The uropygial gland, also known as the preen gland or oil gland, is located over the proximal dorsal tail base. The gland is bi-lobed and has a common central papilla with a tuft of short feathers. The gland secretes an oily liquid that is used to maintain feather quality. The lobes should be symmetric and free of lesions. It is often most easily found by palpation first, then visualization.

Cloacal Palpation (Chickens)

In hens, perform cloacal palpation using a gloved and lubricated finger. Many of the same structures appreciated transcoelomically may be felt, including the cloaca itself, oviduct, ventriculus, gastrointestinal tract, and potential free fluid. Cloacal palpation may be helpful when assessing a hen for egg binding, as the egg may be palpable.

Evaluation of the Sick Avian Patient

Physical examination of a sick bird can be intimidating, and a triage examination may be necessary. Initially weighing the bird with its crate and then subtracting the weight of the crate can allow the examiner to obtain a body weight without the need for a second restraint. For the rest of the triage examination, determine a body condition score; auscultate the heart, lungs, and air sacs; palpate the coelomic cavity; and evaluate the ulnar vein and refill time. These quick steps can provide a great deal of information about the patient.

Summary

The physical examination of psittacines and galliformes follows the same basic principles as for small animals. Practice improves both comfort level in handling avian patients and the speed of the examination. Developing the ability to recognize a sick bird, as well as honing skills around the distant examination, will also be beneficial. Use of sedation may reduce stress levels for both the bird and the clinician.