1. health and fitness
2. disease

HOW TO BE AN AVIAN SUPER TECH
Kristina Palmer-Holtry RVT
As veterinary medicine becomes more specialized, veterinary technicians with specific fields of expertise are
increasingly in demand. The field of avian & exotic pet medicine can be challenging and very rewarding.
Incorporating exotic pets into a veterinary practice will require additional education, training and perhaps some new
equipment. In school veterinary technicians are taught very little about avian and exotic medicine. The same
principles of veterinary medicine with regards to canine and feline medicine can be applied to the exotic pet. Most
veterinary technicians will need to acquire continuing education and further training prior to working with these
unique pets. There are many resources available to assist with training including attending seminars and becoming
members of various exotic species organizations. These organizations are indispensable sources of knowledge and
information and include an international network of approachable experts in these fields. Veterinary technicians that
develop an interest in exotics should obtain additional texts that go into more depth regarding the husbandry,
anatomy and physiology, diagnostic techniques, medicine, and surgery for the different types of exotics being added
to a practice.
Professional Exotic Species Associations and journals
 American Association of Zoo Veterinarians http://www.aazv.org, Journal of Zoo and Wildlife Medicine
 Association of Avian Veterinarians http://www.aav.org, Journal of Avian Medicine and surgery
 Association of Exotic Mammal Veterinarians http://www.aemv.org, Journal of Exotic Pet Medicine
 Association of Reptilian and Amphibian Veterinarians http://www.arav.org, Journal of Herpetological
Medicine and Surgery
 International Association for Aquatic Animal Medicine http://www.iaaam.org, AAAM News
 National Wildlife Rehabilitator’s Association http:///www.nwrawildlife.org, Wildlife Rehabilitation
Bulletin
 Wildlife Disease Association http://www.wildlifedisease.org, Journal of Wildlife Diseases
Recommended Reading
 Altman RB et al, Avian Medicine and Surgery, Philadelphia, 1997, W.B. Saunders Company
 Carpenter, J.W.: Exotic Animal Formulary. Ed3, 2005, St. Louis, W.B. Saunders Company
 Johnson-Delaney, Cathy A et al, Exotic Companion Medicine Handbook for Veterinarians, 1996, Wingers
Publishing, Inc.
 Harrison G, Lightfoot T: Clinical Avian Medicine Vol. I & II, Palm Beach, 2006, Spitz Publishing Inc.
 Mitchell M, Tully, T: Manual of Exotic Pet Practice, 2009, St. Louis, Saunders Elsevier
 Ritchie BW, Harrision GJ, Harrison LR: Avian Medicine: Principles and Application, Lake Worth, 1994,
Wingers Publishing, Inc.
 Harcourt-Brown, Chitty, BSAVA Manual of Psittacine Birds, 2005, Gloucester, British Small Animal
Veterinary Association
 Ritchie, B.W.: Avian Viruses, 1995, Lake Worth, Wingers Publishing, Inc.
 O’Malley, B.: Clinical Anatomy and Physiology of Exotic Species, 2005, Germany, Elsevier Saunders
 Silverman, S., Tell, L.A.: Radiology of Birds An Atlas of Normal Anatomy and Positioning, 2010, St.
Louis, Saunders Elsevier
 Mader, D.: Reptile Medicine and Surgery, 2006, St. Louis, Saunders Elsevier
 Silverman, S., Tell, L.: Radiology of Rodents, Rabbits and Ferrets An Atlas of Normal Anatomy and
Positioning, 2005, St. Louis, Elsevier Saunders
 Stocker, L.: Practical Wildlife Care, 2000, Malden, Blackwell Science Ltd
 West, G. et al.: Zoo Animal and Wildlife Immobilization and Anesthesia, 2007, Iowa, Blackwell Publishing
Preparing the hospital for exotic pets
Working with these unique pets presents new challenges every day. You never know what is going to walk, fly or
slither through the door. Some challenges can be: Capture and restraint, examinations, administering medications,
collecting blood samples, radiographs, anesthesia and how to properly house these patients in your hospital a large
variety of species.
Client Education and The Front Office
Preventive medicine is an essential element of avian medicine and education is the first step. It is important to
provide the veterinary staff with the necessary training to guarantee their success in managing and educating clients.
All staff should be provided with a basic understanding of nutrition, safe and adequate caging, household hazards,
hygiene and bird behavior. Husbandry means animal care in captivity. We need to recreate what life would be like if
the patient were in its native environment; to the best of our abilities. Educating the clients about appropriate diet is
essential for the animals well being. The use of handouts indicating proper diet and housing are very useful since
these are instructions that are in writing and the client can take home to refer to later. Problems resulting from
improper husbandry and diet are the #1 reason for an exotic pet to visit a veterinary clinic.
History
The key to a thorough physical is a detailed history. A history form can be created for the different species seen and
the client can complete the form while waiting to be seen. Identify the chief complaint. Determine the duration of
the observed problem or problems. Evaluate the patient’s overall husbandry, diet and environmental conditions. Try
to streamline your questions, and make sure to take good notes. While obtaining the history it is advantageous to
visually evaluate the patient while it is resting in the carrier or cage. Evaluate the mentation and stance. If the animal
trying to sleep, exhibiting signs of dyspnia or neuropathies, then immediate medical attention may be necessary.
Physical Examination
The physical exam is not all hands on. A lot of information can be obtained simply by observing the patient’s
behavior and physical appearance prior to capture and restraint. Exotics are commonly a prey species with survival
instincts and frequently alter their behavior when they are in a stressful environment, such as a clinic. Some animals
will mask their symptoms in order to not stand out in their “flock” or “group” so they will not be eliminated by a
predator or members of their own group. Evaluate the patient’s ability to recover from the stress of transport to the
clinic. The respiratory rate should be smooth and regular and a healthy animal should show no signs of increased
effort. If a bird is exhibiting a tail bob, forward movement of the head or open beak breathing this could be a sign of
respiratory distress and may need immediate attention.
The patient experience needs to be non-threatening and safe. Approach the patient quiet, calmly, soothing vocal
tones. Even though the patient may act as if it wants to kill you, you must show compassion for them at all times.
These are not just pets, these are family members. The client experience needs to be pleasant and informative.
Restraint is often required for the safety of the patient and the personnel. You will need to learn how to safely and
confidently capture and restrain your exotic patients to perform various procedures such as a thorough physical
examination, and many different diagnostic and therapeutic procedures. Competent knowledge about avian and
exotic species and handling of these patients will inspire confidence in you client.
Capturing the patient needs to be done in a room that can be sealed and has no escape route or hiding places for the
animal to get to. Close and lock the door, close window blinds, and remove any cage accessories. Darkening the
room may help reduce the stress of capture in some cases, such as smaller birds that otherwise try to fly around in
their cages. When working with critically ill patients it is best to perform your physical exam in stages giving the
patient time to recover.
Infectious Disease and Zoonoses
Patients suspected of having infectious diseases, must be isolated from other patients. Isolation areas must be out of
the mainstream of the clinic, where there is minimal foot traffic. Ideally the isolation room should have a ventilation
system separate from the main clinics system. Disposable protective shoe covers or foot baths must be used when
exiting this room to prevent carrying any infectious agent out of the isolation area.
All veterinary team members who handle animals suspected of having a zoonotic or any infectious disease must
wear personal protective equipment not only to protect themselves against infection but also to prevent transmission
to others. Personal protective equipment includes disposable outer garments, lab coats or coveralls, disposable head
or hair covers and gloves, safety goggles, and disposable particulate respirators approved by the National Institute
for Occupational Safety and health. Disposable equipment should be considered contaminated and be properly
disposed of after use. Non-disposable items such as lab coats and goggles should be cleaned and disinfected between
uses. When removing contaminated protective equipment, personnel should remove their outer garments—except
for gloves—first and discard them. They should then remove their gloves, wash their hands with soap and water,
remove their goggles and particulate respirators and immediately wash their hands again. If soap and water are not
available, an alcohol-based hand gel is sufficient. NOTE: Washing your hands is the number one way to prevent the
spread of disease, so do it between each patient regardless of the patient’s potential for carrying an infectious
disease. Using these protective measures will help prevent the spread of disease in your clinic and protect those
working with the patients. Reliable, accurate and timely information about zoonotic and infectious diseases and
personal protection can be found at:
 Center for Disease Control and Prevention, www.cdc.gov
 World Health Organization, www.who.int
 National Institute of Allergy and Infectious Diseases, www3.niaid.nih.gov
 Occupational Safety and Health Administration, www.osha.gov
Infectious diseases in avian species:
 Chlamydophila psittaci Zoonotic
 Psittacine Beak and Feather Disease Virus (PBFDV); Circovirus
 Avian Polyoma Virus (APV)
 Psittacid Herpes Viruses (PsHVs) or Pacheaco’s Disease
 Paramysovirus 3 (PMV-3)
 Exotic Newcastle Disease Virus
 Psittacine Proventricular Dilatation Disease (PDD)
 Papillomaviruses
 Adenoviruses
 Avian Influenza
 West Nile Virus (WNV)
 Eastern Equine Encephalitis (EEE)
 Poxviruses
 Mycobacterium sp Zooinotic
 Fungal infections like aspergillus sp.
Anatomical uniqueness found in birds
 Normal body temperature—depending on species 39-42°C, higher than most mammals.
 Ciracadian pacemaker system—physiological clock that controls the annual calendars of birds by
synchronizing a bird’s internal state with its seasonal environments.
Integument:
 Plume—Down feathers have non-interlocking barbules and provide an undercoat for insulation.
 Fluffed Birds—Cold birds fluff their feathers and crouch to retain heat.
 Powder down feathers—produce a keratin material that creates a dry lubrication and insulation function
and are located anterior to the hips. These feathers are prominent in cockatoos, cockatiels and African grey
parrots. These grow continuously and develop abnormalities if the bird is infected with the circovirus.
 Uropygial gland—A bilobed gland with one duct opening which empties into a lone papilla, found dorsally
at the base of the tail. Found in most Columbiformes and most psittacine species except for Amazon
parrots. Non-essential gland secretes a lipoid sebaceous material that is spread over feathers during
preening to help with water proofing. Impaction or neoplasias are common.
Senses:
 Sight—most birds’ eyes have a very large, asymmetrical globe and 10-18 ossicles (eye bones) that overlap
to form a ring encircling the sclera (sclerotic ring)
 Eye shape—either flat, round or tubular
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Sight—most birds’ eyes have a very large, asymmetrical globe and 10-18 ossicles (eye bones) that overlap
to form a ring encircling the sclera (sclerotic ring)
Ears are located on the sides of the head, behind and slightly below its eyes. It consists of three chambers,
external, middle, and inner. The ear canal is short and horizontal.
Tympanic membrane—separates the external ear from the middle ear and projects outwards rather than
inwards, resulting in otitis externa being an uncommon avian disease presentation.
Gastrointestinal:
 Rhamphotheca—The beak.
 Rhinotheca—the horny keratinized sheath covering the maxilla.
 Gnathotheca—the horny keratinized sheath covering the mandible.
 Kinetic joints—both jaws are connected to the skull by these joints and can move independently.
 Choana—a slit between the palatine folds of the roof of the mouth that closes during swallowing.
 Papillae—caudally directed papillae are abundant in.
 Esophagus—goes down the right side of the neck opposite to its anatomic position in mammals.
 Ingluvies or crop—is a dilation of the esophagus in which food is stored and softened with mucus prior to
its passage into the proventriculus.
 Proventriculus—the cranial glandular stomach is thin-walled and lined with mucus secreting cells which
secrete hydrochloric acid and pepsinogen.
 Ventriculus (gizzard)—is the caudal stomach lies in the ventral position on the left side of the midcoelomic cavity with the pylorus joining the duodenum right of the midline.
 Gallbladder—usually absent in psittacines and ostriches, but is present in many other avian species.
 Cloaca—the common terminal chamber of the genital, urinary and gastrointestinal systems.
 Coprodeum—cranial portion of the cloaca that receives feces from the rectum.
 Urodeum—the middle part of the cloaca into which the ureters enter dorsolaterally on both dies; in makes
the ductus deferens in males and enters near the ureters, while in females a single oviduct enters the
urodeum dorsolaterally on the left side.
 Proctodeum—the caudal part of the cloaca, in juveniles the bursa of Fabricius is located on the dorsal
surface. The phallus, if present, on the floor of the proctodeum. Psittacines do not have a phallus.
 Droppings—Normal bird droppings have three distinct components: liquid urine, semi-solid white or cream
urate, and feces.
 Vent—the external opening of the cloaca. In most avian species the vent is horizontally flattened (i.e.
shaped like lips rather than being circumferential like a mammalian anus).
Respiratory system:
 Nares—fixed and located above the beak and may be surrounded by feathers.
 Cere—the fleshy structure around the nares. In budgerigars the cere is generally blue or pink, smooth in
males and brown and lumpy in females.
 Operculum—a cornified flap of tissue located immediately behind the nares in the nasal cavity.
 Trachea—located on the left side of the ventral cervical area, is mobile throughout its length and contains
complete cartilaginous rings (360°).
 Syrinx—located at the caudal bifurcation of the trachea, and produces voice by vibrations of bilateral
tympaniform membranes during the expiratory phase of respiration.
 Lungs—Are small and located dorsal near the spine and recessed between the ribs. There are no lobes or
alveoli; consequently expansion of the thorax during inspiration is minimal and occurs by extension of the
intracostal joints. In the absence of a diaphragm, the triangular shape of the coelomic (combined thoracic
and abdominal) cavity allows for a bellows-like effect during breathing. Both inspiration and expiration
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require active muscle contraction. Breathing takes two complete breathing cycles to pass through the avian
respiratory system.
Air sacs—Gas exchange does not occur in the air sacs, which are hollow spaces with thin walls consisting
of simple squamous epithelium supported by a small amount of connective tissue. Poor vascularity
Paired caudal air sacs: caudal thoracic and abdominal (in psittacines)
Paired cranial air sacs: cervical and cranial thoracic (in psittacines)
Unpaired medial sac—with several diverticula (clavicula) (in psittacines)
Reproductive:
 Daylight hours—and other environmental triggers are important in initiating reproductive activity.
 Testes—internal and paired and are located craniomedial to the cranial pole of the kidneys and caudal to
the adrenal glands.
 Ovary & oviduct—In most avian species apart from raptors and kiwis, only the left ovary and oviduct
develop.
Renal:
 Kidneys—Birds have paired kidneys recessed into renal fossae. There are three lobes, anterior, middle and
posterior, in which there is no renal pelvis.
 Renal Portal System—avian kidneys receive over half of their blood supply from the renal portal system,
which comes as venous blood from the large intestines and pelvic limbs via the internal and external iliac
veins, the ischiadic vein and the caudomesenteric vein.
 Renal Portal Valve—a smooth muscle sphincter under combined adrenergic (causing valve closure) and
cholinergic (allowing valve opening) control; located between the renal portal vein and the common iliac
artery. If the valve is open blood flows directly into the vena cava. If the valve is shut blood is forced into
the renal portal vein and from there to the peritubular capillary network within the cortical region of the
lobule.
 Uric acid—is produced by the liver, transported in the blood and excreted by means of glomerular filtration
and tubular secretion.
 Urine—urine is drained by ureters, which empty into the urodeum; it is then moved by retroperistalsis into
the rectum, where resorption of water and salt takes place.
 Excretion of water and nitrogenous wastes by birds combines processing by the kidneys and the intestines
and in some species the action of slat-secreting glands.
Circulatory:
 Heart—four chambered and is larger and beats faster than that of a mammal of the same size. Surrounded
by the liver caudally and the lungs dorsally.
Skeletal:
 The avian skeletal system is efficient, strong, lightweight and aerodynamic. Specific adaptations along with
the bird’s feathers, muscles and specialized circulatory and respiratory systems enable flight. Many avian
bones are fused to decrease weight, increase strength and improve aerodynamics.
 Birds have two types of bones: pneumatic and medullary.
 Pneumatic—linked with air sacs and filled with air, found in the skull, vertebrae, pelvis, sternum, ribs,
humerus and femur.
 Medullary bones—long bones with large medullary cavities and thin cortices.
 Vetebral Column—divided into cervical, thoracic, lumbar, sacral, and coccygeal sections.
 Occipital condyle—the first cervical vertebra; a single ball-and-socket device for attachment to the skull.
Enabling an extremely mobile neck.
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Synsacral—fused lumbar, sacral and caudal vertebra. This plate fuses with the pelvis to provide a stiff
framework for support of the legs. Acts as a shock absorber during landings to protect the legs and back.
Ribs—the first few ribs are relatively short and incomplete. The other ribs are complete, attach to the
underside of the sternum.
Uncinate process—a projection that overlaps the adjoining rear ribs to strengthen the rib cage.
Anisodactyl—three toes forward with one toe faces the rear.
Zygodactyl—the second and third toes face forward with the first and fourth toes are directed backward.
Blood Sampling From Birds
Safe diagnostic sampling can be achieved by taking 1% of the bird’s body weight in healthy birds and 0.5% in sick
birds. In the avian patient there are a few sights that can be utilized for blood collection. In order to obtain quality
results blood collected from a severely trimmed toenail is not acceptable. This is painful, stressful and can yield
abnormal cell distributions and cellular artifacts. A venous blood sample should be obtained. The three most
common sights are the medial metatarsal vein or leg vein, the jugular vein, and the ulnar or basilic vein also referred
to as the wing vein. The ulnar vein should only be used in anesthetized patients.
Blood collected for hematology should be collected into a tube containing EDTA as the anticoagulant. Because
avian blood does not store well, such as during transport to a lab, CBC’s run soon after collection are preferred over
those performed several hours later. A blood film should be made if the blood is going to stay in the EDTA for any
length of time. EDTA exposure may cause increased disruption of cells in the blood film. EDTA will cause
hemolysis of erythrocytes in some birds including Corvidae, currasows, cranes, hornbills, and a variety of water
fowl. Consult with your lab, if using one, to verify the species that have had this problem. Lithium heparin can be
used as an alternate anticoagulant to EDTA. A very important fact to remember in the lab is that erythrocytes and
thrombocytes in birds are nucleated and interfere with the counting of white blood cells using electronic cell
counters.
Interpretation of the Avian Hemogram
Blood is made up of several components and functions to carry nutrients, oxygen, and hormones to cells; to carry
metabolic wastes from the cells; to control and prevent disease; and to regulate a bird’s body temperature. Blood
consists of RBCs, WBCs, platelets and plasma.
Erythrocytes (RBCs): In birds these are larger than mammals, oval, nucleated that live around 30 days (compared
to 120 days in mammals). In general HCT should fall between 35-55%.
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A PCV less than 35% is indicative of anemia and a PCV greater than 55% is suggestive of dehydration or
polycythemia.
RBC polchromasia is indicative of red blood cell regeneration. In normal birds this range is between 1% 5%. An anemic bird with 5% or less degree of polychromasia is responding poorly to anemia. An anemic
bird showing a 10% or greater degree of polychromasia is showing a marked regenerative response.
Hypochromasia can be associated with certain nutritional deficiencies, especially iron deficiency.
Hypochromasia has also been seen in lead toxicosis.
Thrombocytes are nucleated cells that act as platelets. They are smaller than red blood cells and have a large, round
to oval nucleus. They are important in blood clotting and are produced by bone marrow in adult birds.
Leukocytes (WBCs) are important in helping fight disease. In adult birds WBC’s are primarily produced by the
spleen.
 Stress leukocytosis occurs in a variety of avian species when the patient is observed to be excited or
“stressed” secondary to transport, handling and restraint. This should be kept in mind when reviewing an
avian leukogram.
Granulocytes:
Heterophils the equivalent to the mammalian neutrophil and is the most frequently observed leukocyte in the avian
hemogram. They are generally round, have a bilobed nucleus with clumped chromatin, and have rod-shaped, redorange granules in the cytoplasm: Phagocytic cells that engulf foreign matter.
 Heterophilia is found in acute inflammatory and infectious processes, including chlamydophila, bacterial
and fungal infections.
 Toxic heterophils, when present, suggest the presence of a septicemia or toxemia.
 Heteropenia can be due to bacterial sepsis and severe viral disease. Artifactual hertopenia can follow poor
blood smear techniques.
Eosinophils in birds resemble mammalian eosinophils but may not be found in all avian species. Their function may
differ from mammalian eosinophils, but his is still not well understood. They are round cells with a lobed nucleus
and large, red-orange, round granules in the cytoplasm. Their numbers increase in response to allergic reaction and
heavy internal parasite loads.
 Eosinophilia can be observed in a variety of alimentary tract parasitism, suspected allergic, non parasitic
conditions and resolving tissue damage.
 Eosinopenia is not well documented in birds.
Basophils are uncommon in avian peripheral blood and their function is still being investigated. Basophils appear to
participate in the initial phase of the acute inflammatory response, but may not always show as a basophilia in the
leukogram. Identified by a round, centrally placed nucleus and stain dark blue. Peripheral basophilia may suggest
early inflammation and possibly hypersensitivity reactions.
 Basophilia is observed in respiratory infections or resolving tissue damage. Basophilia can be found in
birds with an active chlamydophila infection.
 Basopenia is not well documented but many normal avian hemograms show no basophils.
Mononuclear Cells:
Lymphocytes are the essential components of the immune system and are second in frequency next to heterophils.
Their centrally placed nucleus is round and contains densely clumped chromatin. They are produced by the thymus
and bursa of Fabricius.
 Lymphocytosis occurs with antigenic stimulation associated with certain infections, lymphocytic leukemia
and lymphoid neoplasia. Lymphocytes can appear with varying degrees of reactivity.
Monocytes are phagocytic cells that act as a body’s second line of cellular defense. These are the largest leukocytes
found in the peripheral blood films of birds. The nucleus is often shaped like a kidney bean and can be located
centrally or off to one side.
 Monocytosis—can be found with certain diseases that produce chemotatic agents for monocytes, such as
chlamydiosis, tuberculosis, aspergillosis, mycotic and bacterial granulomas and massive tissue necrosis.
Monocytosis can also occur in birds on a zinc-deficient diet.
Hematology Reference Ranges for Amazon Parrots
(Avian Medicine: Principles and Application by Ritchie Harrison & Harrison)
RBC (x106)
2.4-4.0
WBC (103)
6.0-11
HCT (%)
37-50
Hb (g/dL)
1.0-17.5
MCV (fl)
85-200
MCH (pg)
28-55
MCHC (g/dL)
22-32
Heterophils (%)
55-80
Eosinophils (%)
0-1
Basophils (%)
0-1
Monocytes (%)
0-3
Lymphocytes (%)
20-45
Interpretation of the Avian Biochemistry
Biochemistries can be run on plasma in most laboratories. A larger plasma yield can be achieved by using a
microtainer containing lithium heparin. Using serum microtainers can produce a fibrin clot, immobilizing some of
the valuable serum used for sampling, thus requiring a larger amount of blood to be taken from the patient.
Enzyme evaluation: When the integrity of a cell is damaged enzymes escape into the surrounding fluid
compartment and into the serum/plasma. Enzymatic-based tests are a measurement of cell damage and not
necessarily a measure of organ function.
 Aspartate Aminotransferase (AST): High levels have been found in liver, skeletal muscle, heart, brain and
kidney damage.
 Alkaline Phosphatase (AP): Elevations of this enzyme can be due to irritation of cells in many different
tissues. Elevations are most common in liver disease, enteritis. Low AP levels have been linked to dietary
zinc deficiencies.
 Alanine aminotransferase (ALT): activity occurs in many different tissues in birds. Elevated activities are
difficult to interpret. The specific diagnostic value of these enzymes in birds is poor.
 Creatine Kinase CK (CPK): Elevations are mostly seen with muscle cell damage. This enzyme has value in
distinguishing muscle from liver cell damage.
 Glutamate Dehydrogenase (GLDH): A mitochondrial enzyme found in numerous tissues. Found in liver,
kidney and brain. Increases in this enzyme occur when cells are necrotic or markedly injured but not
necessarily inflammatory processes.
Electrolytes: Balanced electrolytes are essential for all living matter. The major electrolytes occur primarily as free
ions.
 Chloride: A major extracellular anion essential to the maintenance of water distribution in the body,
osmotic pressure and the normal anion:cation ratio. Elevations in chloride concentrations are rarely
detected but can occur in cases of dehydration.
 Potassium: The major intracellular cation. Vital for muscular and cardiac function, respiration, nerve
impulse transmission and carbohydrate metabolism. Hyperkalemia can be caused by severe tissue damage,
reduced potassium excretion by diseased kidneys, adrenal disease or because of redistribution of potassium
from the intracellular to the extracellular fluid (acidosis). Hypokalemia may be caused by decreased
potassium intake, increased potassium loss as in diarrhea and a shift of potassium from the extracellular to
the intracellular fluid (alkalosis).
 Sodium: The major cation of plasma and interstitial (extracellular) fluid. Sodium plays a major role in the
distribution of water and maintenance of osmotic pressure of fluids in the body. Hypernatremia can occure
from increased sodium intake, excessive water loss or decreased water intake. Hyponatremia may be due to
increased sodium loss as in kidney disease or severe diarrhea.
 Bicarbonate: The second most common anion of plasma. It is an important part of the bicarbonate/carbonic
acid buffer system and aids in transport of carbon dioxide from the tissues to the lungs, which helps keep
the body pH in balance. Bicarbonate levels are useful for establishing whether or not acidosis or alkalosis is
present and if so, the degree of severity. Increases are mainly due to metabolic alkalosis and decreases are
due to metabolic acidosis.
Nutrients and Metabolites: These measurements provide information about the functional capacity of the organs
that are involved in a particular metabolic pathway.
 Plasma Ammonia: High blood ammonia concentrations may indicate reduced liver function or ammonia
toxicity (rarely reported in companion birds)
 Amylase: Increases can be seen with acute pancreatitis, but little information is available on amylase
activity in birds.
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Bile Acids: The liver synthesizes the primary bile acids, cholic acid and chenodeoxycholic acid. These
acids are excreted as sodium salts in the bile. When food is ingested the bile acids act as emulsify agents in
fat digestion and absorption. Most bile acids are reabsorbed or recycled in some manner with very small
amount remaining in the blood. This fraction of unextracted bile acids is what is measured. Bile acids in the
plasma are normally higher following the ingestion of food. If liver function is impaired, bile acids are not
properly reabsorbed from the blood and the levels are elevated in peripheral circulation. This test is a very
sensitive test for evaluating liver function in birds.
Uric Acid: This test is widely used in birds for the detection of renal disease. If reference ranges are
available, hyperuricemia is a good indicator of renal disease. Normal uric acid concentration does not
guarantee that the kidneys are healthy.
Calcium (Total): Calcium exists as three fractions in avian serum: ionized as a salt, protein bound
(primarily with albumin), and complex with a variety of anions such as citrate Calcium should always be
interpreted along with albumin concentrations. Any condition affecting serum albumin levels will affect the
total serum calcium concentration, due to alterations in the protein-bound calcium fraction, but the serum
ionized calcium level will not necessarily change.
Calcium (Ionized) Ionized calcium is the physiologically active fraction of serum calcium The
measurement of ionized calcium levels is therefore considered the most accurate reflection of the patient’s
calcium status, especially in a diseased animal.
Creatinine: A metabolite of creatine. Severe kidney damage can lead to increased levels. This test
parameter is very insensitive and is a relatively poor diagnostic test in birds.
Phosphorus: The diagnostic value is poor in birds. Increase plasma levels can be seen in some cases of
severe kidney damage due to hypervitaminosis D, nutritional secondary hyperparathyroidism and
hypoparathyroidism. Hemolyzed samples can give false elevations.
Glucose: Pathologic changes in birds are seldom detected. Glucose should be evaluated in convulsing birds
or those with glucosuria.
Total Protein: This test is often used as an indicator of the overall health of a patient. Results can help in
diagnosing gastrointestinal, hepatic or renal diseases.
Lactate Dehydrogenase (LD): Found in skeletal muscles, cardiac muscle, liver, kidney, bone and red blood
cells. Elevated enzyme activity can be observed in liver and muscle damage.
Urea: Present in very small amounts in avian plasma. Increased levels can be indicative of renal disease in
pigeons and can be used as a sensitive indicator of dehydration in other species.
Cholesterol: This is a major lipid that is a precursor of all steroid hormones and bile acids as well as a
component of the plasma membrane of cells. Elevations can occur in cases of hypothyroidism, liver
disease, bile duct obstruction, starvation or high fat diets. Decreased levels are associated with some cases
of liver disease, aflatoxicosis, reduced dietary fat, E. coli endotoxemia and spirochetosis.
Biochemistry Reference Ranges for Amazon Parrots
(Avian Medicine: Principles and Application by Ritchie Harrison & Harrison)
Alkaline Phosphatase (U/L) 15-150
ALT (U/L)
5-11
AST (U/L)
130-350
Amylase
(U/L)
205-510
BUN (mg/dL)
3.5-5.3
Calcium-total (mg/dL)
8.5-14
Cholesterol (mg/dL)
180-305
Creatinine (mg/dL)
0.1-0.4
CO2 total (mmol/L)
13-25
CPK (U/L)
55-345
GGT (U/L)
1.0-12
GLDH (U/L)
0-9.9
Glucose (mg/dL)
LDH (U/L)
Lipase (U/L)
Phosphorus (mg/dL)
Potassium (mmol/L)
Sodium(mmol/L)
Total bilirubin (mg/dL)
Total protein (g/dL)
Triglycerides (mg/dL)
Uric Acid (mg/dL)
Bile Acids (µmol/L)
T4 (µg/dL)
Albumin (g/dL)
190-345
155-425
35-225
3.1-5.5
3.0-4.5
125-155
0-0.1
3.0-5.0
49-190
2.3-10
20-98
0.1-1.1
1.9-1.05
Avian Radiology
Radiographs are an excellent diagnostic tool and give you a lot of information. Some birds will require heavy
sedation or anesthesia for diagnostic radiographs. The diagnostic value of a radiograph is proportional to the quality
of the radiograph. The positioning of the patient is crucial for a diagnostic radiograph. The standard whole body
views are a ventrodorsal and a right lateral. It is best to ALWAYS take both views. The patient must be straight for
a diagnostic quality radiograph. For the VD place the bird on its back, legs stretched down to expose the coelomic
cavity and the wings need to be stretched out. For the lateral the patient is placed in right lateral recumbency, legs
stretched downward, and wings pulled back together.