06 Physical Examination.Qxd

CHAPTER 6 Maximizing Information from the Physical Examination BOB DONELEY, BVS c, FACVS c (Avian Health) ; GREG J. HARRISON, DVM, Dipl ABVP- Avian , Dipl ECAMS; TERESA L. LIGHTFOOT, DVM, Dipl ABVP-Avian The last ten years have seen amazing advances in diagnostic testing capabilities in avian medicine. Tests that were not even considered a decade or two ago are now commonplace. However, the cornerstone of good avian medicine is still the careful evaluation of the patient. Diagnosis Diagnostic tests are an important part of that evaluation, but they are not the whole evaluation. Their use is only a part of a continuum that starts with a careful anamne- Diagnostic Testing sis and concludes with a diagnosis. This can be illustrated by the diagnostic pyramid shown (Fig 6.1). Astute clinicians will move carefully through these levels, refining their differential list through careful history tak- Physical Examination ing, physical examination and selection of diagnostic testing until a final diagnosis (or at least a much short- ened list of differentials) is reached. Anamnesis Understanding the Fig 6.1 | The Diagnostic Pyramid Masking Phenomenon A common misconception held by many bird owners and veterinarians is that birds are not very resistant to illness. To the novice it often appears that birds show signs of illness one day, are at the bottom of their cage the next, and dead the day after. This misconception has stemmed from two sources. First, many of the birds seen in practice are only a few generations descended from wild birds. As such, they retain many of the protective instincts inherited from their forebears. Many avian species kept as companions are relatively low on the food chain. These protective instincts have been developed to avoid drawing the 154 Clinical Avian Medicine - Volume I Greg J. Harrison Greg J. Fig 6.2c | This canary’s illness has wasted away all the pectoral muscle. One must observe the bird in a quiet situation — waiting Greg J. Harrison Greg J. Greg J. Harrison Greg J. a few minutes for the masking behavioral Fig 6.2a | The bird’s natural masking Fig 6.2b | Observing a caged bird is defense to wane and the fluffing to recur. A phenomenon misleads owners and an art well worth perfecting. Outwardly, history of a small bird that has not eaten in a many veterinarians. They think the bird this dead canary appeared fine to the day and has scant feces denotes a very sick is fine, until the bird decompensates owner who brought the bird to the bird. See discussion under Fig. 6.42a-d prior and shows overt signs of illness. This veterinarian. The bird died moments to handling such a sick bird. blue budgerigar is showing the signs of after examination. the latter stages of illness and is “sleep- ing” and “fluffed up.” In the same envi- ronment, the yellow bird is keenly alert. attention of predators. One such instinct is often known and the ease with which early clinical signs can be over- as the “masking phenomenon.” Predators are naturally looked highlight the importance of regular health exami- drawn to prey that look or behave differently from oth- nations for the companion bird. Long-standing condi- ers. Unusual coloring, weakness or lameness can single tions such as malnutrition can be detected and cor- out a bird and make it attractive to a predator. A natural rected before the bird begins to decompensate and instinct is therefore to avoid appearing “different.” A sick shows overt signs of illness. bird will make a determined effort to look healthy, even in the absence of predators. The classical “sick bird look” we usually associate with illness — fluffed feathers, closed eyes, lethargy — only develops when the bird is History Taking incapable of masking these signs (Fig 6.2a). Therefore, The collection of an accurate and thorough history of a many of the patients presented to veterinarians are past patient is as crucial to making a diagnosis as is the physi- the initial stages of their illness and are now decompen- cal examination and comprehensive diagnostic testing. A sating rapidly. good history can alert the clinician to likely problems and allow him/her to refine the diagnostic approach. Secondly, due to lack of experience, most owners and many veterinarians may miss subtle changes in a bird’s behavior or appearance that are indications of a health SIGNALMENT problem. Overlooking these early signs, combined with The first step in obtaining a history is to gain as much the bird’s efforts to mask obvious clinical signs, invari- information about the bird itself as possible. A good ably leads to the delayed detection of illness and the receptionist or technician can often obtain such informa- presentation of the bird in extremis (Figs 6.2b,c). It is tion. The clinician should be familiar with avian taxon- important that veterinarians learn to recognize early omy, sexual dimorphism, and species-specific behaviors. signs of illness, and educate their clients, so that ill- Clients are often unaware of some basic facts about their nesses can be detected before becoming too advanced. A bird (such as species, sex and age). Veterinarians intend- physical examination form, used routinely by veterinari- ing to see avian patients regularly need to acquire a ans and support staff, allows thorough and methodical working knowledge of commonly kept bird species and documentation of the essential parameters of the physi- their physical characteristics. Such knowledge, while cal examination (Fig 6.2c). The “masking phenomenon” available in some publications, is generally acquired Chapter 6 | MAXIMIZING INFORMATION FROM THE PHYSICAL EXAMINATION 155 through experience and through being proactive and PATIENT HISTORY inquisitive. This may require visiting other veterinarians, How long have the clients owned this bird? (Fig 6.5) aviaries, avian pet stores and zoologic collections and Birds that have been in the owner’s possession for many will take some time to acquire. years, with no recent exposure to other birds, are less The species of the bird is the first key piece of informa- likely to have infectious diseases (Fig 6.6) and are more tion. Many clients are unaware of the correct identifica- likely to be suffering from underlying chronic conditions such as malnutrition or inadequate exercise. Recently tion of their bird, or may refer to it by a local name unfa- obtained birds are more likely to have been in close con- miliar to others. The cockatiel (Nymphicus hollandicus) is tact with other birds and, as such, have possibly been known all over the world as the cockatiel or ‘tiel, except exposed to infectious diseases (Figs 6.7-6.9). in Australia (the bird’s native land), where it is more commonly known as the Quarrion or, in Western Australia, as Where did the owner obtain the bird? the Weero (Figs 6.3a-f). The clinician needs to be able to With experience, the clinician will be able to identify recognize common species and have access to illustrated “problem sources” of birds in the local area (ie, a certain literature that will enable the clinician to confirm the sci- breeder with a history of circovirus, bird fairs or a pet entific name and to identify unfamiliar species (see shop renowned for chlamydial problems). Developing a Chapter 2, The Companion Bird for selected photos). working knowledge of the quality of the sources of pet Knowledge of the species can offer the clinician vital clues birds in your area can be a key element of patient evalu- to likely differential diagnoses for the sick bird and appro- ation in your practice (Fig 6.10) (see Chapter 2, The priate preventive medicine and husbandry during well- Companion Bird). ness examinations. For example, black cockatoos (Calyp- torhynchus spp.) and some macaws require more fat in Is the bird aviary bred or wild-caught? (Fig. 6.11) their diet than many other psittacines. The same diet fed Wild-caught psittacines, although less common in recent to galahs (Eolophus roseicapillus) and budgerigars (Melo- times, are still coming into the pet market in certain psittacus undulatus) can result in obesity, atherosclerosis parts of the world, such as in Europe. In countries such or hepatic lipidosis. Species-specific behaviors, such as the as Australia, Africa and South America, it is reasonably alarm “snuffing” typical of Pionus spp., is often mistaken easy to obtain a bird from the wild. The challenge of tam- by new owners and veterinarians unfamiliar with this ing a wild-caught bird can be daunting. Paradoxically, behavior as a pathologic respiratory condition. wild-caught (and therefore parent-raised) parrots that survive the rigors of capture and have adapted to interac- The age of the bird, while usually difficult to determine tion with humans, are much less likely to demonstrate once adult plumage has been attained, is another impor- the common behavioral problems of our domestically tant part of the anamnesis. Juveniles are more suscepti- raised parrots. Feather plucking, vent prolapse, inappro- ble to conditions such as rickets, polyomavirus, circo- priate screaming, and learned biting are all more preva- virus and bacterial infections, while adult birds are more lent in captive-raised African greys, Cacatua spp., and likely to suffer from neoplasia, chronic malnutrition and macaws (Ara spp.) Fortunately, improved techniques for degenerative conditions. While owners may not be sure raising these birds are being implemented, and both vet- of the exact age of their pet, they usually know how long erinary and client awareness of the need for continued they have owned it, and that may be sufficient for estab- attention to the emotional well-being of our parrots is lishing an age-specific list of differential diagnoses.

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