Avian Medicine Today

When my client, Mary, brings her newly purchased baby bird in to me for its first check-up, I will perform a physical examination on it, listen to its heart and lungs, weigh it, draw some blood for testing, use my microscope to perform a Gram's stain, take radiographs using a sophisticated machine and special x-ray film, and give her detailed information related to nutrition, first-aid, common diseases, behavior and meeting a bird's emotional needs. I may vaccinate it or give it a booster for polyomavirus. While this all seems routine to today's modern bird owner, it wasn't that long ago that people would only bring their bird to the vet as a last resort, after having already tried all the medications that a pet store had to offer.

Beginning in the late 1970's and early 1980's some forward thinking veterinarians began to take an interest in avian medicine. Veterinarians learned volumes about avian diseases during the importation of psittacines while the birds were quarantined in USDA stations. Veterinarians associated with quarantine stations and wholesalers would often perform surgical sexing of the birds prior to sale, so many veterinarians became adept with using a fiber-optics endoscope to perform the surgeries. Continuing education courses began springing up and veterinary colleges began offering elective classes in avian medicine. Researchers began studying avian diseases more extensively. While poultry husbandry and medicine has been well-established for decades, diseases of psittacines (parrots) and passerines (canaries, finches, etc.) are often very different, as is nutrition.

In the mid-90's, farmers, entrepreneurs and consumers began developing an interest in ratites (emus, ostriches and rheas) as a more healthful source of meat, resulting in an explosion of knowledge about ratite husbandry and medicine.

So, we have come a long way, baby, when it comes to avian medicine and stewardship. Let's take a look at the state of avian medicine today.

Knowing Normals

Avian veterinarians now have at our fingertips information about the normal adult weights of most pet birds, and we have growth charts that allow us to ensure that baby birds are growing at a proper rate. Information has been tabulated that allows us to assess blood values of normal baby birds during the different stages of growth (complete blood counts, CBCs, and plasma chemistry values vary not only between species, but also within a species during the different stages of life). We now know what to expect during the first few months of a baby bird's life; when the eyes open, when the ears open, when feathers emerge, when it will begin to fledge, fly and wean. We know what to feed baby birds up to, during and after weaning. We know how much weight a baby bird should lose during and after weaning.

Methods of proper, safe and humane wing-clipping have been refined over the years. Gone are the days when a bird groomer takes a pair of scissors and hacks off all of the primary and secondary wing feathers at the level of the coverts, leaving a bird with a bunch of abnormal, sharp quills that poke the bird in the ribs, predisposing it to feather picking. Wing trims can be tailored to the specific species of bird, allowing it to glide gently to the ground and not crashing like a ton of bricks which may result in a broken, bleeding beak, split skin over the keel or other injuries. Toenails can be regularly trimmed, and in-between, a specifically designed pedicure perch can be placed in the cage to keep the sharp points worn down, although a professional trim will still be needed occasionally to shorten the length.

We now know much more about the general nutrition of pet birds. For example, when extruded pelleted diets first came out, many owners jumped on the bandwagon, wanting to provide the best for their pet birds. However, over time, it was discovered that many cockatiels, aged seven to ten years of age, began developing signs of kidney failure. Since cockatiels and budgies really are primarily seed-eaters in the wild, it was felt that the new pellets were too high in certain nutrients, such as protein and vitamin D3, resulting in premature kidney failure. Pellet manufacturers have corrected the nutritional imbalances, so now pelleted diets should be very safe. This goes to show that although we know volumes more than we did a decade ago, there is still much we need to learn, especially in the area of avian nutrition. For example, for most species of birds, we still don't know what constitutes their normal diet in the wild, including the seasonal changes in available foods consumed.

There are now atlases that show radiographs with detailed anatomical charts, assisting veterinarians in determining normal avian anatomy from pathological changes associated with disease conditions. At our disposal, we also have access to board certified radiologists who have a special interest in avian medicine. We can now take quality digital photos of your bird's radiographs (x-rays) and send them as an e-mail to a radiologist for evaluation. That way, a specialist can review the radiographs and offer an opinion, which is a great boon for the avian veterinarian who doesn't see many birds in practice and is not confident in their own skills at reading rads, or even for the experienced avian vet who is seeing something unusual and requires a second opinion.

Bird behavior has been studied over the years, and now birds exhibiting abnormal behaviors, such as feather picking, can be referred to qualified bird behaviorists, once medical problems have been ruled out. Behaviorists can be consulted by phone or e-mail, in addition to the more traditional housecall.

Thirty years ago, bird breeders rarely used avian vets for help with their breeding flocks. Now, many avian vets are well-versed in avicultural medicine and work closely with breeders to help them produce healthy, disease-free, socially well-adjusted baby birds for the pet trade. Avicultural vets also work with breeder flocks to ensure that they remain healthy, and are working with many endangered species to provide medical support for their captive propagation with genetic diversity.

Avian veterinarians now can take their education one step further and become board certified in avian practice by the American Board of Veterinary Practitioners. Avian veterinarians who have completed a residency program in avian medicine or who have been in practice for five years or more may apply to take the exam by submitting two publishable papers in avian medicine and surgery, submit several letters of recommendation and provide a detailed synopsis of their avian practice, including what tests they perform, what types of surgeries they perform and their avian case-load. If they are accepted to sit for the exam, they must then pass a very comprehensive test, in several parts, that encompasses all areas of avian medicine and surgery. Only then may they be called avian specialists. This distinction has only been available for about a decade. Fifteen years ago, having board certified avian specialists was a goal, but nowhere near a reality.

Veterinary diagnostic laboratories now offer consulting services for their clients. Veterinarians seeking help on challenging cases or wishing for a second opinion can now consult with avian specialists who can provide information regarding interpretation of lab tests, recommendations for additional diagnostics, treatment protocols and surgical options. So no veterinarian practicing avian medicine need feel that they are alone out there when it comes to dealing with their avian patients.

There are now continuing education courses and conferences that offer a wide array of topics for avian practitioners. Conferences offer classes for every level of expertise, from introductory courses for new graduates of veterinary colleges and practitioners beginning to practice avian medicine, all the way to advanced sessions for avian specialists and those vets studying to become board certified. All across the country, and all around the world, conferences are held to advance the knowledge of avian medicine. Also, web sites and veterinary professional sites offer places for avian vets to post questions, offer advice, chat with other avian vets or to read the newest information on avian topics. Any motivated avian veterinarian can easily remain up-to-date in avian medicine with the vast and diverse information that is available in a number of forums.

Testing

We now have at our disposal a wide array of sophisticated tests in order to best diagnose pet and aviary birds. In addition to radiographs, some sophisticated veterinary practices and referral centers now offer advanced imaging. Ultrasound, which uses sound waves, not radiation, to create a picture of internal organs, is a safe, non-invasive technique that can be used to diagnose tumors, heart defects, internal organ abnormalities and other diseases. One advantage to ultrasound is that anesthesia is not usually necessary. In addition to radiographs, using high speed film for mammograms in humans, the newest technology employs taking radiographs digitally, which can be displayed immediately on a computer screen, eliminating using toxic chemicals to develop x-ray film, and also eliminating potential errors in the development of the films, as well. Veterinary radiologists are also available to evaluate ultrasound exams and other advanced diagnostic imaging techniques.

Large veterinary referral centers may have the most sophisticated imaging equipment available today, or they may have an agreement with human facilities to utilize their equipment. CT scans (computerized tomography) and MRIs are advanced techniques enabling avian vets to perform detailed studies of the avian body. Although not commonly employed, tests using injected isotopes or dyes can be used to perform organ studies.

Cardiac exams can also be performed, utilizing ECG (electrocardiograms), echocardiograms (using ultrasound), dye studies, radiographs and blood tests. Some species of birds, including African Greys, seem more susceptible to heart-related problems such as atherosclerosis (hardening of the arteries).

Board certified specialists who's specialty is in an organ system of all species, such as cardiologists and ophthalmologists, for example, may often be willing to apply their expertise to avian patients. This can be very helpful when a patient has a particular problem that could benefit from the knowledge of such a specialist.

Complete blood counts can be performed on almost any size patient, using just a few drops of blood. Blood chemistries to evaluate organ function and examine electrolytes (calcium levels, potassium, sodium, etc.) are routinely performed on small quantities of blood (actually plasma is used, which is the blood with the cells removed). Chemistry analyzers utilize very small amounts of plasma to perform sophisticated tests. In cases where birds, especially African Greys, are having problems with seizures associated with low blood calcium levels, labs can now perform a specialized test to determine ionized calcium levels that may be more helpful in determining exactly what is going on concerning calcium metabolism in the bird.

Protein electrophoresis, a test that separates out the different fractions of a bird's protein levels, can be used to determine if acute or chronic inflammation or infection are present, and can be a very useful test to help diagnose psittacosis, aspergillosis and other diseases.

In addition to the many blood tests that can be utilized to help diagnose specific diseases, such as titers, which measure antibodies to certain disease-causing organisms, newer tests have been developed that are very specific and precise, to help us diagnose avian diseases. These new tests are called DNA PCR tests, and they actually look for pieces of the DNA from certain organisms. Since PCR tests do not rely on the body's response to an organism, or require growing the organism, these tests are very reliable and rarely result in false-negative results. If a bird is shedding the Chlamydophila organism (that causes psittacosis), and a DNA PCR test is run on a pooled choanal/cloacal swab, the test will come back positive, unlike cultures, which can be unreliable. We have PCR tests for Chlamydophila, polyomavirus, Psittacine Beak and Feather Disease (2 variants), mycobacterium (tuberculosis), Pacheco's Disease, as well as other diseases. In addition to performing DNA PCR tests on swabs or blood from live birds, it is also possible to run DNA hybridization tests on processed tissue samples that were used for histopathology (staining and examination of tissues under the microscope). Using this technique, suspicious lesions on a histo slide can be tested using a DNA probe to determine if specific organisms are present. This is a great advance in technology, so if swabs are not taken in advance during a necropsy, for DNA PCR testing, it may still be possible to run the probe on histo samples.

As new emerging diseases begin appearing in pet birds, researchers at universities and diagnostic laboratories work quickly to develop tests that can help in their diagnosis. For example, there are already tests available to aid the practitioner in the diagnosis of West Nile Virus, both in live and dead birds.

Many organizations and agencies are set up to deal with any outbreaks of disease in birds. For example, when Exotic Newcastle's Disease broke out late last year in California, members of the Association of Avian Veterinarians in California were sent a packet of information about the outbreak, including sterile swabs and mailers to send off tests for suspected cases. Sending out this information to avian vets greatly aided government officials in helping to control the outbreak.

Advances in Surgery

In addition to regular surgery that is routinely performed on avian patients, many avian vets employ advanced equipment to aid in performing successful delicate surgery. For example, a radiosurgical unit is often used to greatly aid in controlling bleeding, which is so important in avian surgery, especially when performed on neonates. When compared to an electrocautery unit that is often used in human and dog and cat surgery, a radiosurgical unit is much safer for avian patients. Electrocautery units create a good deal of lateral tissue damage to cells on either side of the blade when it is used for cutting or cauterizing (stopping bleeding) due to thermal injury, whereas the radiosurgical unit, using radio waves, causes minimal tissue damage.

Microsurgical techniques have been employed for years in avian medicine, using a surgical microscope to perform delicate surgeries. Now, the newest techniques in surgery utilize the application of a laser unit for surgery. Carbon dioxide lasers can be used for a variety of surgical procedures in birds, including performing tumor removal, biopsies of tissues, removal of reproductive organs, papilloma excision and crop biopsy, to name just some applications. The advantages of laser surgery include the minimal amount of tissue damage during surgery, and very good control of hemorrhage. Lasers can be used for delicate procedures, such as removal of eyelid masses. While at this time lasers are very expensive, some referral centers and specialty practices are now offering laser surgery as an option.

Endoscopic procedures have been available for avian patients for quite some time now. Endoscopy began as a method to surgically sex birds with no outward signs of sex (monomorphic), by making a small incision into the left side of the bird under anesthesia, and then passing a small, rigid fiber-optics endoscope (initially designed for human joint surgery) into the body cavity to look for the gonad (testicle or ovary). Today, endoscopy can be used to remove infectious granulomas, biopsy tissues, assess internal organs and repair certain internal problems. These procedures are minimally invasive, requiring a very small incision site, and rapid healing time.

Newer anesthetic agents are available that provide very safe anesthesia for surgical procedures in avian patients. Newest anesthetic agents include isoflurane and sevoflurane, gases that are inhaled to provide a sleep-like state and pain control for surgery. Gases are administered via a small, clear chamber that the bird is place in, or by a mask, and then once the bird is asleep, it will often have a tube placed in the windpipe (trachea) and the anesthetic agent will be administered with oxygen. In cases where the oral cavity is the surgical site, it is possible to place an air sac tube into the body cavity of the bird, and the anesthesia can be administered that way, leaving the oral cavity, beak and trachea open and available for surgery. There have been excellent advances in pain control and management before, during and after a surgical procedure, so that no bird need suffer needlessly after surgery or after an injury. Many different drugs have been studied that provide safe and effective relief from pain.

Therapeutics

Many excellent antibiotics are available for treatment of bacterial diseases in birds. While most antibiotics were developed and labeled for use in humans, dogs or cats, they are often used in avian medicine. New antibiotics are continually being developed, and universities and research facilities study them to develop treatment protocols. Many avian vets work with compounding pharmacists to provide avian patients with oral, palatable, liquid antibiotic and antifungal preparations. Medications may be delivered by injection (subcutaneous, intravenous, intraosseous, intramuscular), oral, intratracheal, topical or inhalation (by nebulization) routes.

There are many drugs that are effective for bacterial, mycoplasmal, Chlamydophila, fungal, protozoal and parasitic infections. There are even a few drugs available that will actually treat viral infections. However, some of the newer drugs in the avian arsenal are those that can be used to treat certain cancers in birds. Several protocols have been developed to treat lymphosarcoma, leukemia and osteosarcoma in avian patients. Other drugs can be used to lower cholesterol, to help control blood sugar levels in diabetics, to increase gastrointestinal motility, to treat ulcers, to control egg-laying, to treat cardiac disease, to help control symptoms of Proventricular Dilatation Disease (PDD) and drugs to help control obsessive behaviors related to feather picking.

The state of avian medicine today means that, no matter where you live, you and your avian vet have access to state-of-the-art medical care for your bird, whether by consultation with a board certified avian specialist, via telemedicine or by referral to a university or referral center. Your bird deserves the best and in many ways, the best is available to you.

Cadeusus
Copyright 2006 Margaret A. Wissman, D.V.M., D.A.B.V.P.
All Rights Reserved
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