Seminars in Avian and Exotic Pet Medicine最新文献

After a description of anatomy and physiology of the avian respiratory system, an approach to the dyspneic patient is discussed. Diagnostics that may be helpful in determining the cause of dyspnea include radiographic imaging, ultrasound, cytology of sinus or tracheal flushes, and endoscopy. Various avian respiratory diseases that may present on an emergency basis are described along with therapeutic options.

Increasing numbers of exotic animals are being kept as pets, and owners want to receive high-quality medical care for these pets. Treatment of hypovolemic shock and critical care monitoring in exotic pets are complicated by small patient size, physiological diversity, and lack of research and clinical data on their response to therapy. Despite these impediments, the same principles and techniques of monitoring used in domestic animals can be applied to the exotic patient. The goal of this article is to provide an in-depth presentation on the principles and pathophysiology of shock, types of fluids, monitoring techniques, and shock resuscitation methods for use in rabbits, ferrets, small mammals, and birds. An understanding by the veterinarian of the patient’s cardiovascular state and the characteristics of crystalloid and colloid fluids available is necessary for establishing a fluid therapy plan. Arterial blood pressure measurement is an important tool in the management of the critically ill pet. The message of clinical importance is that fixed fluid regimens (eg, Lactated Ringers), fixed volumes (eg, mL/kg) and rules of thumb are in most instances outdated, inappropriate and often times inadequate. Appropriate fluid therapy, combined with frequent patient evaluation and periodic blood pressure monitoring techniques, can produce astounding and at times miraculous results.

Cardiopulmonary-cerebral resuscitation (CPCR) is a comprehensive term used to describe both the basic principles of cardiopulmonary resuscitation (CPR) as well as advanced life support and postresuscitation care. Although there are numerous publications on CPCR in humans and small animals, there is little written on CPCR in special species. This article outlines the basic principles of CPCR, including the current recommendations from the human International Guidelines 2000 Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Although many of the basic principles of CPCR are applicable to any species, the important physiologic differences when applying these principles to special species are discussed. When appropriate, potential modifications are proposed for individual species. The final portion of the paper includes special considerations for avian, reptile and small mammals, as well as quick reference charts for CPCR in small mammals and avian/reptile patients.

Encephalitozoon hellem is a single-celled, intracellular parasite of the phylum Microspora. E. hellem was first recognized in immunosuppressed humans where it causes keratoconjunctivitis, sinusitis, and, uncommonly, systemic disease. Increasing evidence strongly suggests that birds are the primary host for E. hellem and that most bird infections are self limiting and do not result in disease. To date, commercially raised lovebirds appear to have the highest prevalence of spore shedding of the birds examined. When disease does occur in birds, it is usually associated with another immunosuppressive infection, inadequate husbandry, or immaturity. The kidney, liver, and intestine are the most common targets of infection, but lesion distribution is variable. Disease has been documented in a wide range of companion birds including parrots and finches, in an ostrich, and in wild hummingbirds. Albendazole has been used for systemic treatment of E. hellem and albendazole in combination with fumagillin have been used to treat ocular manifestations of E. hellem.

Exotic Newcastle disease (END) is a virulent strain of avian paramyxovirus-1. This virus has devastated the poultry industry in many countries. As a result, strict international regulations are in place to control the movement of exotic birds, poultry, and poultry products to prevent the introduction of this disease into countries where it has been eradicated. When END is introduced to a naı̈ve, unvaccinated population of poultry, mortality may reach 100%. Signs in chickens will depend on the strain of END involved. However, this disease should be suspected in any outbreak of disease in poultry where there is high mortality and respiratory, gastrointestinal and/or central nervous system signs are observed. In the most recent END outbreak in the United States, many birds had edematous heads, cyanosis, and diphtheritic lesions of the trachea, oral cavity, and esophagus. Signs in companion birds are variable and often nonspecific. Practitioners, however, should suspect this disease in parrots, particularly Amazon parrots, if the sick bird is of questionable origin and over the course of the disease develops signs related to the central nervous system. Efforts to keep END out of the United States have been largely successful; however, on repeated occasions in the last 30 years, END has entered the United States through the illegal transport of fighting chickens and psittacine birds. In two cases, END has made it into commercial poultry operations, resulting in the slaughter of millions of birds and a significant economic impact to poultry and exotic bird producers. Education about this disease, strict biosecurity measures, and continued vigilance will be necessary to prevent future outbreaks of END.

Salmonella bacteria, especially Salmonella enterica, serotype Typhimurium, are commonly found in the intestine of wild birds. These organisms are maintained within bird populations by several mechanisms. The simplest of these mechanisms occurs in raptors since birds that eat other animals risk eating Salmonella-infected prey. Both wild and captive raptors may be temporary or permanent Salmonella carriers or even suffer from clinical Salmonellosis as a result of eating infected prey. A similar infection pathway affects scavenging or carrion eating birds such as vultures, crows, and, most importantly, gulls. For example, gulls are opportunistic scavengers who feed at sites where raw sewage is released. They appear to be relatively resistant to disease but may serve as effective carriers of Salmonella and thus are a source of infection for other animals. In other situations, birds exposed to a contaminated environment may become infected accidentally. This is the case with domestic pigeons and colonial waterbirds. The most significant outbreaks of wild bird Salmonellosis occur, however, in passerines. Thus, although only a few healthy passerines harbor Salmonella in their intestine, these birds often gather in very large numbers at bird feeders. The growth of the “bird feeding industry” has promoted this behavior. Garden bird feeders can become so contaminated with feces that Salmonella contamination may grow to significant levels. If this is accompanied by other stresses such as bad weather or a food shortage, large numbers of these birds may develop Salmonellosis and die. Finches, house sparrows, and cowbirds appear to be especially at risk. Phage and genetic typing suggests that these passerines carry strains of S. enterica Typhimurium that are specifically adapted to songbirds. These infected birds may transmit infection to humans, either directly as a result of handling, or more commonly, as a result of exposure to domestic cats infected by preying on sick and moribund birds.

Prairie dogs (Cymonys spp.) are native to North America. They have proved to be a relatively popular pet in North America and in multiple countries around the world. All or the vast majority of prairie dogs sold in the pet trade are wild caught. Two zoonotic diseases that naturally occur in wild prairie dogs are tularemia and plague. Epizootics of both of these diseases have occurred in recently captured prairie dogs intended for the pet trade. The lot containing prairie dogs with tularemia was widely distributed within the United States and internationally before the disease was recognized. Recently, prairie dogs intended for the pet trade were exposed to monkeypox as the result of close contact with several species of wild caught African rodents. Infected prairie dogs developed a systemic disease with cutaneous manifestations. Prairie dogs were distributed to six states before the disease was recognized. As many as 76 people developed monkeypox from exposure to these prairie dogs. The last reported case was in June 2003. Currently, it is illegal to buy, sell, trade, or transport prairie dogs in the United States. However, veterinarians are still permitted to treat them.

The evolution of West Nile virus (WNV) has resulted in the emergence of WNV variants that have a significant pathogenicity for humans, horses, and birds. WNV appeared in North America in New York City in 1999 and has since spread throughout the continent into the Caribbean and Mexico and is now believed to be enzootic in much of the United States and southern Canada. Crows, the blue jay, chickadees, hawks, and owls appear to be the most susceptible to WNV disease, although mortality has been reported in nearly 200 species of birds. Disease in companion birds is rare. WNV disease in birds is rapidly fatal and signs, if they occur, are predominately of the central nervous system. Characteristic necropsy findings in birds are intraosseous hemorrhage of the calvaria, an encephalitis, myocarditis, and pancreatitis. Infection can be confirmed by PCR, antigen detection, and virus isolation. Chickens and turkeys are refractory to WNV disease, and chickens have been used to monitor WNV activity. Domestic geese appear to be relatively susceptible to WNV disease. Outbreaks of WNV in Europe, Israel, and the United States have resulted in a significant number of cases of meningitis, encephalitis, and acute flaccid paralysis in people. Encephalitis has also been a common sequella to WNV infection in horses in Europe, North America, and Africa. WNV disease occurs sporadically in many other species of mammals and has been reported to cause significant mortality in a commercial operation of alligators.