Seminars in Avian and Exotic Pet Medicine最新文献

Abstract

Echocardiography in birds is a useful intravitam technique for morphological and functional cardiac assessment, although the technical equipment has to be advanced to examine the avian heart. Probes with small coupling surfaces and frequencies of at least 7.5 MHz are necessary, and ultrasound devices should be able to produce at least 100 frames/s. A bipolar ECG is used to examine the heart in endsystolic and enddiastolic stage. Two approaches for coupling the probe are described. By using the ventromedian approach, two horizontal longitudinal views present the chambers, the interventricular septum, and the valves of the heart. Reference values for B-Mode and spectral Doppler are available for different species, but experiences with Doppler examinations in diseased birds are still rare. Common pathological echocardiographic findings in birds are hydropericardium, hypertrophy and/or dilation of the right ventricle, and hypertrophy of the muscular right atrioventricular valve.

Based on the available information from canine and feline electrocardiography, an overview of the physiological basis, the indications, limitations, and interpretation of the ECG is presented. Where possible, specific information regarding the avian and ferret ECG is given, and several ECGs from parrots and ferrets with cardiac disease are presented and interpreted.

Reptile cardiology is in its infancy. Veterinarians treating reptiles should develop a basic knowledge of reptile cardiovascular anatomy and physiology. Cardiology is vital to interpreting the results of various diagnostic tests and planning an effective therapeutic plan for a case. This article will provide a review of the anatomy and physiology of the reptilian cardiovascular system, the common diagnostic tests used to assess cardiac function, and the common disease presentations associated with the cardiovascular system.

Waterfowl, whether free-living or in captivity, are hosts to a wide variety of internal and external parasites. With few exceptions, the significance of most parasitic infections is unknown, due, in part, to the fact that mixed parasitic infections are the rule rather than the exception. Therefore, effects of any one parasite species must be made in light of the other parasites, diseases, or stressors (eg, malnutrition) that may be present. Furthermore, the pathogenicity of a parasite may differ among species of birds as well as different populations of the same species. Experimental assessment of the effects of some parasites have been attempted using the mallard duck as the model; however, in light of species differences, the applicability of such studies to other species of waterfowl is unclear. Of the several hundred parasites that are present, nasal leeches, Leucocytozoon simondi, certain species of coccidia, some nematodes, the trematode Sphaeridiotrema globulus, cestodes in the genus Gastrotaenia, and some acanthocephalans have been associated with morbidity and/or mortality in captive or wild waterfowl. Detection of many parasitic infections can be accomplished through traditional diagnostic techniques (eg, fecal flotation, blood smears); however, the presence of parasites does not automatically equate with the presence of disease. Control and treatment measures are few, especially for free-ranging waterfowl. However, excellent sanitation can help combat many parasites in captive situations.

Viral disease can cause substantial mortality in wild populations of ducks as well as domesticated geese and ducks. Migrating and captive waterfowl play a role in the dynamics and epidemiology of some viruses that also infect humans, such as influenza virus and West Nile virus. Crowded farm conditions favor the transmission of infectious disease agents among birds. Disease transmission is further facilitated by the comingling of wild anatids with nonmigratory resident waterfowl flocks in zoological parks or on farms. The following article will emphasize the most important viral diseases of waterfowl and briefly cover the newer diseases of suspected viral etiology in this group of birds. As viral detection and identification techniques become more and more sophisticated, and as the study of wildlife diseases increases, new viruses will be discovered and new diseases will be encountered. More research into the viral diseases of waterfowl is needed; the implementation of the latest techniques in molecular epidemiology in addition to the “gold standard” techniques such as virus isolation and histopathology, will yield insight into how viruses move from species to species and from region to region.

Although chickens and turkeys comprise the majority of poultry species seen by the private practitioner, on occasion, backyard waterfowl such as ducks and geese, are also brought into the private practice setting. In order to treat our waterfowl patients expediently, it is important to be familiar with the common diseases often reported in backyard waterfowl species. As veterinarians, not only do we have to be familiar with common waterfowl diseases, but we also have to be aware of the environmental situations that may enhance some of these disease conditions.