chapter notes


avian events





Companion Avian Medicine


Keven Flammer, DVM, keven_flammer@ncsu.edu
Office D-250, Ext. 36353 (Call for an appointment)

Goals of This Portion of the Course:
1. Gain an appreciation for the importance of avian medicine in veterinary practice.
2. Be able to efficiently capture, restrain, and examine a bird. (click to view video/listen to audio segments describing these techniques).
3. Be able to instruct your future technician on how to collect an appropriate blood sample, cloacal swab and choanal swab from an avian patient. (click to video/audio segments describing these techniques).
4. Be able to collect a history for a companion bird case.
5. Be able to advise a new bird owner on appropriate husbandry, cage and perch selection.
6. Be able to advise a new bird owner on proper feeding of psittacine birds and canaries.

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A. Numbers: Large numbers of birds are kept as pets and aviary specimens. The US caged bird population is approximately 15-25 million. The most popular caged birds are the small psittacines (especially budgerigars and cockatiels) and canaries (a passerine bird). Larger psittacines (such as conures, parrots, cockatoos and macaws) are less commonly owned but more frequently brought to veterinary practices.

B. Impact on veterinary practice. AVMA surveys indicate that companion avian medicine is a profitable area, especially for small animal practitioners. Many bird owners also own dogs or cats and desire a single practice to care for them. Prior to 1985 few veterinarians saw birds, now most small animal practices offer routine care. The Association of Avian Veterinarians has approximately 3500 members. There are approximately 70 board certified avian veterinarians (American Board of Veterinary Practitioners).

C. Bird sources: Prior to 1993, most birds in the pet trade were imported (0.5 million/year). The Wild Bird Protection Act of 1992 eliminated most, but not all, psittacine importation. This caused a rapid shift in the pet industry and has impacted avian medicine because:
1. Domestic production is now the primary source of companion birds. This has increased the importance of aviculture and pediatric medicine.
2. Many diseases that were historically common due to the stress and crowding of importation, are now less common (e.g. poxvirus, beak and feather disease, etc.).

D. Why study birds? Because there is a need, clients will demand your services, it is enjoyable, it breaks the routine of small animal practice, and it is economically profitable.

E. Diversity: Birds are classified in the Kingdom Metazoa, Phylum Chordata, and Class Aves. There are four other classes in this same phylum: Mammalia, Amphibia, Reptilia, and Pisces. The term "avian medicine," therefore, encompasses a group of species with as much physiological, behavioral, and ecological diversity as the mammals.
1. Within the Class Aves, there are 27 Orders comprised of approximately 8,600 species. Birds from only 7 of these Orders are routinely seen in a non-zoological veterinary practice, and practicing veterinarians commonly sees only 2 orders. Since time in this course is limited, these lectures will concentrate on the companion bird species comprising the bulk of private practice, the psittacine birds and the finches.

F. General Bird Facts
1. Birds are biologically adapted to hide signs of disease to avoid predators and avoid being chased out of their flock. They will often preserve normal behaviors until they can no longer compensate. So a sudden onset of illness is common and a bird that acts ill is sicker than what you would expect with a dog or cat showing similar signs.
2. Ill birds often show the same set of clinical signs, regardless of the cause of illness. This constellation of clinical signs is called the "sick bird syndrome" and includes: Depression, anorexia, ruffled feathers, inactivity, decreased vocalization, dull eyes (due to dehydration), and sparse dark green feces (due to anorexia and bile staining).
3. Poor husbandry and poor nutrition underlie many bird health problems. Most birds are not good at self-selecting a healthy diet, even if a large variety of food is offered.
4. The normal alimentary tract flora of companion birds is gram positive. They are susceptible to infections from gram negative bacteria and yeast acquired from other birds or environmental sources.
5. Few psittacine birds are sexually dimorphic. Gender determination based on observation of behavior is unreliable. Birds are most commonly sexed with a blood test (DNA probe for the W chromosome of the female) and can also be sexed via endoscopy.
6. Most psittacine birds are moderately expensive. Hand-reared cockatiels cost approximately $50-100, conures $250-500, Amazon parrots $400-1500, African grey parrots $500-1,000, macaws $800-6000, and cockatoos $700-15,000. Add another $50-1000 for a cage and toys.

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The companion avian history is similar to that of other species. Since infectious diseases are common, it is important to record the origin of the bird, note how long the owner has had it, and investigate any possible contact with other birds. Poor diet and husbandry also contribute to health problems. Questions to ask include:

What are the problems and how have they progressed?
Ask what the problem looked like when first noticed and how it has changed. Define what problems are currently present. Include progression and any treatments the owner might have attempted.

What is the origin of the bird?

1. Birds are often obtained from pet stores, breeders, and private parties. They may also be purchased from flea markets, bird marts, wholesalers, and rarely, from smugglers.
2. Birds in contact with other birds (e.g. swap meets and pet stores) have greater changes for exposure to infectious diseases. Birds from private households have greater risk for behavioral and nutritional problems, depending on the standard of care.
3. Different pet shops and breeders have different standards of care. Disreputable and inexperienced dealers frequently have problems with microbial infections and chlamydiosis.

How long has the client owned the bird?

1. Recently purchased birds are more likely to break with infectious diseases due to the stress associated with a change in environment.
2. Birds from a stable household are more likely to experience nutritional and chronic disease problems, but acute bacterial infections do occur.

What is the purpose of the bird?

1. The emotional attachment of bird owners to their pets is similar to cat or dog owners. The economic value of the bird may be a secondary consideration.
2. Aviculturists will be concerned with the future breeding potential of the bird.
3. Bird owners with multiple birds will be concerned about the disease risk of any ill bird to the rest of their collection.

What is the reproductive status of the bird?

1. Reproducing hens may experience behavioral changes, egg binding, salpingitis and other problems that would not be present in a male bird.
2. Both male and female birds may become aggressive and territorial during the breeding season.
3. Many psittacine birds are not sexually dimorphic so the sex may not be known.

Have any new birds been added to the household or collection in the past three months, or has the bird come in contact with other birds?

1. You will want to know the species, age, health status and date of acquisition for all new birds.
2. Investigate the history of new birds to determine if they are suspect for carrying infectious diseases.
3. Question the quarantine practices the owner followed in introducing the new birds. Husbandry notes in the following sections will discuss quarantine.
4. Consider potential exposure to other birds during boarding or visits to/from households with other birds.

What other species does the client own, and are they sick?

1. The presence of disease in several birds suggests presence of an infectious agent.
2. Some birds are common carriers of certain diseases. For example, cockatiels are common carriers of chlamydiosis (psittacosis).

What diet is fed, and more importantly, what does the bird actually eat?

1. The presence of a balanced seed diet does not mean that the bird is eating everything offered. Ask what percentage of the diet actually consumed is made up by high fat foods such as peanuts and sunflower seed.
2. Birds become habituated to familiar diets and may resist a diet change.
3. Poor nutrition is a common underlying cause of other diseases.
4. Commercial parrot pellets usually provide the best source of nutrition. Ask what percentage of the diet consumed is composed of pellets.

H. Has the owner tried any forms of treatment themselves?

Some bird owners will administer "over the counter" preparations containing tetracycline or erythromycin first, and then call a veterinarian if this fails. Treatment may affect diagnostic tests such as cultures and blood counts.

I. Interpret the owner's comments carefully.

Birds are masters at hiding their signs of disease and most people are not trained to recognize subtle symptoms. Even observant clients may not realize their bird is sick until the disease is well advanced. Common misinterpretations include:
1. The bird wasn't sick until last night. (In fact it may have been sick for a long time but the bird masked signs of disease or subtle signs were missed.)
2. Runny droppings-since the urine and feces are combined in the same dropping, clients may confuse polyuria with diarrhea.
3. Bird's appetite. Birds will often maintain feeding behaviors but not actually consume food. The client may think the food cup is full, when in fact it contains empty seed hulls or crushed (but not eaten) pellets.

J. Is the bird allowed out of the cage- Supervised or unsupervised?

Psittacine birds are notorious "chewers" and can get into trouble if left unsupervised. Flighted birds may land on the stove or collide with ceiling fans, walls or windows.

K. Has there been any exposure to potential toxins? For example:

1. Psittacine birds like to chew lead (stained glass, curtain weights, bell clappers, bullets, fishing sinkers, lead paint, etc.)
2. Potential sources of zinc include galvanized wire, galvanized food and water bowls, and snap links used to hang toys.
3. Ask if any insecticides or rodenticides have been recently used.
4. Teflon fume toxicity. Can occur if a Teflon-coated surface is burned (>550o F) and releases polytetrafluoroethylene gas. The gas causes acute pulmonary hemorrhage and death. Sources of "Teflon" include non-stick cookware, irons, ironing board covers, self-cleaning nonstick ovens, and Teflon sprays.
5. Some carpet fresheners, scented candles, and aerosol sprays can cause toxicity (respiratory failure and death).

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Poor husbandry underlies many disease problems, particularly in avicultural collections where housing may not be ideal. Some questions to ask and things to note:

A. Cage size and construction.
1. The minimum size cage should permit the bird to extend its wings in all directions without touching the sides. Birds should be able to perch without dragging their tail.
2. Cages for the smaller, more active birds (e.g., finches, parakeets and cockatiels) should permit enough room for flight. This is less important for the larger psittacine birds, or if the owner allows supervised exercise periods inside the home.
3. Hardware cloth (soldered wire) should not be used for cage construction since the solder contains lead and zinc. Welded wire that is galvanized after welding can be used, but zinc toxicosis can occur if chewed (especially if the wire is of poor quality). The safest cages are made from brass or powder coated steel.
4. Better cages are constructed with a wire floor that allows spilled food and droppings to pass through the floor and out of the cage.
5. If there are multiple birds in the cage, is it large enough? Birds that are overcrowded may fight and feather-pick each other.
6. Ask what substrate is used on the bottom of the cage. Paper products are best. Corncob bedding can grow Aspergillus fungus; sand may cause impaction if ingested.

B. Perches-are they appropriate?

1. Perches should provide a variety of “perching diameters”. Dowels of uniform size are less desirable since they force the bird to perch in the same position ? which can lead to abnormal foot wear. Suitable perches can be made from cloth rope, sisal rope, plastic, and nontoxic natural branches such as manzinita, fruit or nut wood.
2. Sand paper covered perches should not be used-they will abrade the bird's feet. Concrete perches manufactured specifically for birds are OK and aid in keeping nails trimmed, but must be of the appropriate size and used intermittently.
3. Perches made from PVC pipe are useful for hospital and isolation facilities since they are easily disinfected. They must be grooved to provide a rough surface so the bird can grip.
4. Perches should not be placed over food and water cups, or the bird may defecate in the cups while perching.

C. Food and Water Containers

1. All containers should be constructed of a nontoxic, easily cleaned material such as ceramic, plastic or stainless steel. Aluminum and galvanized steel containers should not be used. Large psittacines will destroy thin plastic cups.
2. All bowls should be placed to avoid contamination by feces.
3. Water containers should be washed and refilled daily, especially if vitamins are added.
4. Water bottles are more hygienic than bowls, but birds must be trained to recognize them as a source of water. They should be washed 4-7x weekly.
5. It is helpful to separate the food and water containers to discourage birds from placing food in the water.
6. It is helpful to have two sets of bowls so one set can be used while the other is cleaned.

D. Toys

1. Toys are essential for most birds but should not clutter the cage. Many birds will be fearful of new items.
2. Inappropriate toys can be dangerous. Consider the size of the bird and its ability to break or chew the toy. Bells may have a zinc or lead clapper. Fasteners may be a source of zinc. String toys may be ingested. No one certifies toys as safe, so purchase from a commercial or “bird source” does not guarantee that the toy is appropriate for all birds.

E. General Hygiene

1. Note the cleanliness of the cage, perches and food and water cups. Ask the client how often the cage and dishes are cleaned. Cages for individual pet birds should be cleaned at least 3-4 times each week. Fresh water should be provided daily and bowls holding water; fruit or other easily spoiled food should be washed daily.
2. Fruits and vegetables should be removed from the cage within 4-24 hours of being offered.
3. Food or water that the owner would not consume themselve should not be fed. "If you wouldn't feed it to your baby, don't be feeding it to your birds"… (said in an Irish accent).

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A. Diets Commonly Fed to Companion Birds
1. Seed mixes - millet, canary and oats to small birds; sunflower, safflower and peanuts to larger birds.
2. Fruits and Vegetables
3. Commercial parrot pellets
4. Table food
5. Nutritional supplements
a. Vitamins

b. Minerals
c. Calcium source (cuttle bone, mineral block, powdered supplement)

B. Avian Feeding Behaviors

1. What the bird eats is more important than what's offered. Psittacine birds become habituated to certain foods and may select a narrow range of items, even if offered a smorgasbord.
a. They especially like sunflower seeds and peanuts and may eat these to the exclusion of everything else.
b. Birds are not good at self-selecting a nutritionally balanced diet.
2. Many birds are intolerant of rapid changes in their diet, and may even be fearful of new food items.

C. The most commonly recognized nutritional disorders in pet birds are:

1. Obesity in Psittacine Birds. Commonly associated with feeding all-seed diets since peanuts, sunflower and safflower seeds contain 30-50% fat. Some species are particularly prone to obesity (e.g. Amazon parrots, rose-breasted cockatoos and blue and gold macaws) and may become fat even on pelleted diets. Birds eat to satisfy energy requirements so a high fat diet can also result in relative nutritional deficiencies.

2. Vitamin A Deficiency. Associated with birds fed unsupplemented all-seed diets. It causes squamous metaplasia of epithelial surfaces and renders the bird more prone to respiratory and alimentary tract infections. Clinical signs include blunting of the choanal papillae and oral abscesses.

3. Protein Quality Deficiency. Associated with unsupplemented all-seed diets. Lack of high-quality balanced protein can cause dull plumage, increased susceptibility to disease, and decreased reproductive success. Lysine, methionine, and tryptophan are often deficient in seed diets.

4. Metabolic Bone Disease. Associated with unsupplemented all-seed diets. Calcium deficiency, calcium/phosphorus imbalance, or Vitamin D3 deficiency may cause this disorder. Calcium deficiency is the most common cause in pet birds. Clinical signs in growing birds include deformed and broken bones, plus swelling and deformity of the ribs. Signs in adult birds are less common but can include egg binding or laying of soft-shelled eggs in hens.
a) Hens have a specific appetite for calcium during egg laying and will readily consume oral sources.

5. Hypervitaminosis D. Caused by over supplementation with Vitamin D3. Toxicity causes calcification of internal organs, primarily the proventriculus, ventriculus and kidney. It is most common in hand-fed macaws and cockatiels. Affected birds will be hypercalcemic and mineralization of the kidneys can result in renal failure, polyuria and uricemia.

D. Dietary Recommendations - the condensed version.

1. 80% Commercial pellet, 20% fruits and vegetables or healthy table foods. Amounts are based on what's consumed.
a) Healthy table foods = items that are healthy for people, excluding fatty foods, spicy foods, salty foods, meat (except for small quantities of chicken or fish), avocado, and chocolate.
b) Do not supplement vitamins with this diet.
2. Vitamins should be supplemented if an all seed diet is used.
3. It is not necessary to offer grit to psittacines. Canaries and finches should be offered grit weekly.

E. Diet changes are stressful so avoid changes during times of stress (e.g., illness, molting, following a recent move, breeding season, cold weather, etc.). Monitor droppings and body weight during a diet change.

F. Diet switching strategies.
a) Feed new diet in morning when birds are hungry, offer old diet in late morning if they fail to eat.
b) Add new food to old and gradually increase the amount of the new.
c) Feed the new food on alternate days, then 4x/week, 5x/week etc.

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Conducting a physical examination in birds is similar to that in most species. Establish a routine so that all systems will be examined.

A. Prior to catching the bird.
1. Warn the client that handling the bird could potentially have harmful effects that are
not in your control.
a. Handling a sick bird could stress it to death. This rarely happens if handling is done properly and quickly. Be especially careful with birds that show respiratory distress (open mouth breathing, tail bobbing, etc.)
b. Handling the bird may damage a few feathers and return the bird in a disheveled condition. This is sometimes unavoidable.
c. Normal handling might slightly bruise the bare cheek patches on macaws.
2. Observe the bird in the cage and note its posture and attitude. Once capture is attempted, the bird will change appearance.
3. Anticipate your needs. The key to successful handling of non-domestic animals is reducing stress by minimizing restraint time.
a. Set out routine exam equipment such as a mouth speculum, stethoscope, penlight, and anticipated equipment such as bandaging material and scissors.
b. Have routine diagnostic equipment such as swabs, microscope slides and bleeding equipment easily available.
4. Secure the room-remove cats and dogs, close doors and windows and remove potential dangers, in case the bird escapes. Close curtains on windows.
5. Dim the room lights-this will calm the bird and make it easier to catch.
6. I prefer to handle the bird myself or with a technician. If the owner handles a tame bird it may resent them after the procedure. Never catch a bird off the owner's shoulder or arm-either one of you could be bitten.

B. Capture
1. In a cage-remove the water bowl and perches and gently grab the bird by the back of the head with a towel. Gloves can be used but they are cumbersome and may make the birds "hand-shy" (birds don't seem to associate the towel with hands).
2. In a flight-catch the bird with a net. Avoid rim shots.

C. Restraint
1. There are two “grips” for holding the head
a. Side-to-Side: Grasp the back of the head at the jaw, between the thumb and index finger. This prevents the head from turning and is the grip to use if the head is being examined or if you are tube feeding a bird.
b. Encircling: Place your thumb and index finger under the jaws of the bird such that the entire head is above your hand. Gently extend the neck. This is more comfortable for the bird, but the head can turn.
2. Hold the legs just above the feet (at the tarsometatarsus) with an overhand grip and finger placed in-between the legs. Avoid grasping the bird higher up on the legs as this is painful and will remove feathers.
3. Control the wings with the fingers of the hand holding the head and “body-English”.
4. Avoid pressure on the sternum or the bird may suffocate.
5. Excessive pressure on the jaws of large birds will cause bruises.
6. The bird can be left in the towel, but this makes a complete examination more difficult.

D. Preliminary examination. Quickly examine the following areas as they may influence how dangerous completing the rest of the physical examination will be:
1. The crop. Birds with fluid in their crop may regurgitate and aspirate during handling.
2. The abdomen. Female birds with a swollen abdomen and dilated pelvis may be getting ready to lay an egg. Handling a bird during egg laying may cause "egg binding" (dystocia).

E. Examination of the head
1. Examine the head and note any asymmetry-pay particular attention to the beak, nostrils and periorbital areas.
a. Swelling in the periorbital area or exophthalmus may indicate sinusitis. Birds have large periorbital sinuses that can fill with inspissated pus.
b. Crusty honeycomb lesions around the eyes and beak may be caused by scaly face mite.
c. Decide if the beak needs to be trimmed.
2. Check the nostrils for enlargement or any discharge. Birds with discharge may also have stains on the beak and matting or loss of the feathers above the cere.
3. Examine the eyes. Signs of disease are similar to that in other animals.
a. Conjunctivitis is common in psittacine birds.
b. Birds have striated muscle in their iris and voluntary control over the pupil. There is no consensual papillary response.
4. Open the mouth and examine the oral mucosa, the choanal slit, and the glottis.
a. Blunting and swelling of the small papillae lining the edge of the choana is usually caused by an upper respiratory infection or vitamin A deficiency.
b. A white pustule with easily removed exudate is suggestive of vitamin A deficiency.
c. Pox or bacterial infections may cause shallow white plaques with an adherent membrane.
d. White or brownish, cheesy lesions are usually caused by bacteria, yeast or trichomonas.
5. Examine the head for signs of feather loss. Feather damage in this area cannot be caused by self-mutilation since this is the one place a bird cannot pick itself. This is an important observation in the differential diagnosis of feather picking.
6. Macaws have bare cheek patches and will "blush" when frightened or angry.

F. Examination of the neck and thorax
1. Palpate the crop for food and foreign bodies. Avoid handling a bird with a full crop as it might regurgitate.
2. Palpate the pectoral muscles.
a. They should be rounded and fill the space surrounding the keel, but muscle conformation differs among species. Amazon parrots are stocky, macaws slightly streamlined, and cockatoos more slender.
b. The muscles should feel firm. Mushy feeling muscles are common in cockatoos, obese birds, and birds that get little flight exercise.
c. Weight loss is rapidly reflected in atrophy of the pectoral muscles. As the muscles atrophy the keel becomes more prominent. This atrophy may not be apparent unless the bird is handled-while the bird is in the cage loose skin and feathers can hide weight loss from even the most trained observer.
d. Disuse atrophy of only one side of the pectoral muscles may be caused by injury
to the wing on that side.
3. Note the condition of the plumage. Look for feather defects such as “stress bars”.
4. Palpate the contours of the neck and thorax for masses and abnormal feathers.

G. Examination of the abdomen and pelvic area
1. Palpate and examine the abdomen-think of it in quadrants. In the normal bird few structures can actually be palpated.
a. Upper mid-left quadrant-the gizzard is a hard, round, lump located just caudal to the sternum. It can often be palpated. Other masses may displace the gizzard.
b. Upper right quadrant-the largest lobe of the liver is located in this area and is not palpable in the normal bird. If severely enlarged this lobe may become palpable.
c. Lower right and left quadrants-usually little can be palpated in the lower abdomen. The presence of masses in this area is abnormal. The normal abdomen of an adult psittacine bird is concave. Nestlings have a convex abdomen.
d. Part the abdominal feathers (or carefully wet with alcohol) to examine the abdomen. Birds have thin skin and enlarged liver lobes can be visualized extending beneath the sternum.
2. Palpate the pelvic bones-in most normal birds there is only a slight separation between them. Shortly before egg laying the bones will separate.
3. Examine the cloaca (also called the vent).
a. Pasting of feathers surrounding the vent by urates or feces is suggestive of polyuria or diarrhea. This will also occur if the bird is unable or unwilling to perch and drags its tail on the cage floor.
b. Tenesmus, papillomas, or an idiopathic syndrome in psittacine birds resulting in hyperplasia of cloacal tissues can cause prolapse of the cloaca.
c. Knemidokoptes mites can infest the cloacal area and cause a honeycombed thickening of the skin.
4. Examine the uropygial (preen) gland. It is found on the dorsal surface at the base of the tail. Swelling caused by blockage of the out flow duct and tumors are the most common problems. Amazon parrots do not have this gland.

H. The Extremities
1. Wings
a. Palpate the bones and extend each joint and assess range of movement. Compare to the opposite side.
b. Examine the flight feathers and assess if the bird can fly-this is important if the bird is in a flight cage and must fly to reach food and perches.
(1) Fault lines in feathers indicate a stressful episode during feather formation.
(2) External parasites such as mites and lice are most easily found on the
ventral surface of the flight feathers.
(3) Feather cysts (ingrown feathers) may cause swollen feather follicles.
2. Legs
a. Palpate the bones and joints.
b. Examine the feet for evidence of abnormal wear from improper perches.
c. Assess the length of the toenails.
d. Record the location and number of the identification band (if present)

I. Auscultate the chest (careful if the bird is screaming!).
1. Listen to the heart over the ventral chest and ventral-lateral body wall. Listen for murmurs and arrhythmias. Auscultation is not as reliable as in mammals due to the rapid heart rate.
2. Listen to the lungs over the dorsal chest area. A very soft rushing sound is normal. Wet noises or pops and wheezes are abnormal.

J. Assess hydration by noting skin turgor on the tops of the feet, or the speed with which the upper eyelid returns to a normal position after retraction.

K. Weigh the bird every time it is examined. Weight loss is one of the earliest signs of disease.

L. Stress/Exercise Response Test
1. Return the bird to its cage-often the stress of the physical exam will make apparent signs the bird was previously hiding.
2. If a group of birds is being examined in a flight cage, force them to fly a few lengths of the cage and assess their stamina. A sick bird will rest earlier than the rest of the group and can be singled out for diagnostic tests.

M. Droppings
1. Avian droppings are composed of three parts:
a. Feces
b. Urates (white, formed portion of the urine)
c. Urine (clear, liquid portion)
2. Feces
a. The feces of psittacine birds should be formed, brownish or dark green in color, and occupy the center of the dropping.
b. Anorectic birds will have sparse, loose, dark green feces (due to the presence of bile). Teach techs and bird owners to recognize this change.
c. Abnormal colors may be associated with disease.
(1) Black-may indicate melena. Check fecal occult blood
(2) Red-may be due to fresh blood (cloacal papillomas or colacitis) or interaction of the feces with substrate (some paper towels) or due to diet (colored pellets, berries).
(3) Dark green, sparse-indicates the presence of bile. Most common if the bird is not eating.
(4) Clay colored-maldigestion or malabsorption. Exocrine pancreatic insufficiency occurs in birds.
(5) Weird colors (purple, blue, etc.) are usually caused by feeding berries or other colored foods.
(6) Passages of whole seeds-causes include lack of grit in small birds, gastrointestinal hypermotility, lead poisoning, avian gastric yeast (megabacteria) and proventricular dilatation syndrome.
c. Diarrhea-causes are the same as for other small animal species.

4. Urine
a. In most birds urine is present as both a watery portion and a solid paste (urates). Desert adapted species, such as budgies, parakeets and cockatiels pass more formed urates. More tropical and frugivorous species, such as Amazon parrots and macaws, pass more watery droppings.
b. Causes of polyuria include excitement, anxiety, consumption of fruits and vegetables, renal disease, increased water consumption (polydypsia), etc.
c. Causes of bloody urine include renal disease, lead poisoning, and bleeding in the cloaca.
d. Causes of green colored urine (biliverdinuria) include liver disease (especially common with psittacosis), and bile staining from feces.
e. Yellow urine is rare. It is usually caused by severe, rapid liver disease (e.g. infection by Pacheco's herpesvirus)

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Blood Collection

A. Sites:
1. Venipuncture of the right jugular, wing (basilar or cutaneous ulnar), or medial metatarsal vein.
a. The right jugular vein is easiest to hit. The left jugular is smaller than the right, but can be used in larger birds.
b. Hematoma formation is common because avian veins are thin walled and fragile. To reduce hematoma formation, use minimal negative pressure, release negative pressure in the syringe before withdrawal, and immediately apply pressure to the venipuncture site.
c. There are a limited number of veins so allocate them for diagnostic sample vs. drug administration.
2. Clipping a toenail. Less desirable than venipuncture as it is painful and the sample
will often clot.

B. Collection Amounts
1. In a normal bird, 1% of the body weight in grams = # of milliliters you can collect (i.e. 1 ml/100 g). This is equivalent to approximately 10% of the total blood volume.
2. Less than 10% of the total blood volume (0.2-0.50-ml/100 g) should be collected from sick birds and even less from severely compromised patients or those where repeated sampling is anticipated.
3. Plasma is most often used for biochemical and serological tests because fibrin clots reduce the yield of avian serum. Heparin is the most widely used anticoagulant.

C. Common Tests: Complete blood count, plasma biochemistry panel, protein electrophoresis, serology for specific diseases (e.g. chlamdyiosis), tests for heavy metal (zinc or lead) .

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A. Microbial infections of the alimentary and upper respiratory tract are common. Cultures and Gram's stain cytology are commonly used diagnostic tools.

B. Normal flora of the alimentary tract is predominately gram positive and includes anaerobic and aerobic bacteria. Common normal aerobic bacteria include:
1. Lactobacillus
2. Corynebacteria
3. Staphylococcus (excluding Staph. aureus)
4. Most Streptococcus (hemolytic Strep. may be pathogenic)
5. Bacillus (present in very low numbers).

C. Common Culture Sites
1. Cloaca-receives most flora from the alimentary tract, but is also the common opening for the urinary and reproductive tracts.
2. Crop/Oral Pharynx-normal flora is similar to the cloaca. Cultures must be interpreted with caution, since transient gram-negative organisms are frequently isolated that are not causing disease. Organisms that are present in large numbers or isolated from repeated samples are more likely to be pathogens.
3. Choana-Cultures reflect the flora of the upper respiratory tract and the oral cavity. Usually cultured when there are clinical signs of an upper respiratory illness (rhinitis, sneezing, etc.). Results can be interpreted as for the cloaca.

D. Culture sites not recommended for routine culture.
1. Voided droppings-In flora surveys, fewer gram?negative organisms are recovered from feces than the cloaca. Yeast can grow in moist newspaper or corncob substrate and contaminate the droppings. If droppings are used, they should be sampled immediately after defecation.
2. Nares-it is tempting to culture nasal exudates and the nares themselves, but many transient organisms are found at the nasal opening that are not causing disease. This makes nasal swabs difficult to interpret.

E. Gram-stained smears of crop and fecal material are useful detecting:
1. Normal flora
2. Yeast (non-pathogenic yeast may be seen in birds fed bread products)
3. Gram negative bacteria
4. Abnormal anaerobic spore forming bacteria.
5. Avian gastric yeast (Megabacterium).

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Page last updated December 10, 2003