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At least 127 records · Page 7Linked to original sources
PubMed1993

Serum enzyme activity evaluated in budgerigars (Melopsittacus undulatus) inflicted with muscle injury.

Aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH) concentrations were measured in 73 budgerigars. In spite of increases in the serum concentration of AST and ALT the loss of enzyme activity from the injection site occurred at about the same rate for all four enzymes tested. The rate constants, calculated in birds administered muscle extract via the intravenous or the intramuscular route of injection, disclosed that in subjects treated intramuscularly the serum enzyme elevation was dependent on the elimination half-life of the enzyme and partly on the rate at which the particular enzyme was absorbed into the bloodstream. Moreover, serum enzyme elevations correlated inversely with total clearance. To determine the aetiology of blood enzyme elevation in budgerigars, for diagnostic purposes, the absorption rate, total clearance and elimination half-life of each of these four enzymes are deemed valuable components.

Alanine Transaminase↗
PubMed1984

Varied egg gas conductance, air cell gas tensions and development in Agapornis roseicollis.

Different color varieties of the small African parrot, Agapornis roseicollis , lay eggs which differ by as much as a factor of 7 in gas conductance. Oxygen consumption (VO2) and air cell gas tensions (PAO2, PACO2) were measured repeatedly on individual eggs during development. No differences were observed in the ontogeny of VO2, incubation period, or hatchling mass of eggs with different gas conductances, in spite of large differences in PAO2 and PACO2. Low conductance eggs reached PAO2 as low as 46.0 torr (6.13 kPa) and PACO2 as high as 90.5 torr (12.07 kPa). Although pipping occurred earlier in low conductance eggs, pipping did not occur at similar air cell gas tensions in eggs differing in conductance. Chorioallantoic membrane development was about 75% complete on day 12 and not fully complete until day 18 of the 22-23 day incubation period. The capacity of avian embryos to develop and hatch normally in eggs of different conductances may be important in allowing adaptation to varying nesting environments.

Animals↗
PubMed1989

Characterization of a new virus from cockatoos with psittacine beak and feather disease.

A novel virus isolated from the feather follicles of cockatoos diagnosed as having psittacine beak and feather disease was characterized by electron microscopy, nucleic acid content, and polypeptide composition. Purified virions displayed an icosahedral symmetry, were nonenveloped, and had a mean diameter of 14 to 16 nm negatively stained. Three major viral proteins were identified, with approximate molecular weights of 26.3, 23.7, and 15.9 kDa. The viral nucleic acid was found to be single-stranded DNA based on acridine orange staining, resistance to alkali and ribonuclease, and sensitivity to both DNAse 1 and S1 nuclease. The size of the DNA was estimated to be between 1.7 and 2.0 kb by agarose gel electrophoresis. This size and its circular conformation were confirmed by electron microscopy. A preliminary transmission study using purified virus induced pathological lesions characteristic of those observed in the natural disease. On the basis of the extremely small size of the virions and the single-stranded circular viral DNA, we propose that the etiologic agent of psittacine beak and feather disease represents a previously undescribed viral pathogen.

Animals↗
PubMed1985

A stereotaxic headholder for Psittacidae.

A stereotaxic headholder suitable for lovebirds is described. In addition to modified ear bars, the head is fixed by means of a clamp gripping the depressions of the lacrimal bones.

Animals↗
PubMed1986

Memory formation in birds: 1. Avoidance conditioning of the budgerigar (Melopsittacus undulatus) to sound stimuli.

A system is described for avoidance conditioning of the budgerigar (Melopsittacus undulatus), for sound patterns consisting of one or two sequential subunits and to discriminate between two closely resembling sounds. Electric shock was used as the unconditioned stimulus. Simple conditioning was accomplished in about 300-400 trials. After a given sound pattern was firmly fixed by conditioning, discrimination between this and a new sound pattern was established relatively rapidly by using several consecutive sessions in which the two patterns were mixed. Discrimination was reinforced by associating the two signals by opposing electric shocks. An overnight rest period after the first few sessions improved the rate of conditioning during the following experimental period. A temporary, partial or complete extinction of conditioning was produced by longer rest intervals, but the original conditioning was reestablished by subjecting the animal to a few trials of reconditioning. Short intercalations of a new conditioned stimulus had no effect on the retention of the original conditioning whereas a random mixing of the first conditioned stimulus with a second produced a temporary decay in the original conditioning. The experimental system described here is useful for studying physiological and biochemical changes accompanying a memory process based on a linear sequence of sound patterns.

Animals↗
PubMed1986

Memory formation in birds: 2. Effects of stress due to experimental procedures on the conditioning of the budgerigar (Melopsittacus undulatus) to sound stimuli.

Conditioning studies involving administration of biochemical or pharmacological agents are often stressful to experimental animals. Some of these stressful manipulations were examined for their effect on the avoidance conditioning of the budgerigar to sound stimuli. There were individual variations in the capacity of the birds to accommodate to these stresses, but generally the stress factors had negative effects on their subsequent conditioning, the degree of this effect depending upon the type and severity of stress. Simple anesthesia with ether had the least effect, intravenous injection being next in severity, while intracerebral injection was most inhibitory. The effects due to anesthesia and intravenous injection could be decreased by delaying the conditioning procedure for 1 to 2 hours following the treatment, but the effect of intracerebral injection was more prolonged. The retrieval of temporarily lost conditioned response through brief reconditioning was not affected by intracerebral injection, indicating that, once a memory trace was formed, subsequent emotional and physical stresses did not obliterate it irreversibly.

Animals↗
PubMed1991

Comparison of isolates of Chlamydia psittaci of ovine, avian and feline origin by analysis of polypeptide profiles from purified elementary bodies.

The single species Chlamydia psittaci is a diverse grouping which contains several different types of chlamydial strain for which there is no generally accepted typing method. The results obtained when profiles of polypeptides from purified elementary bodies are compared are consistent with type designations obtained using other criteria. However, the method still requires large scale culture and extensive purification of the chlamydial cells.

Animals↗
PubMed1995

Chlamydia psittaci infections: a review with emphasis on avian chlamydiosis.

In the first part of this article the general characteristics of Chlamydia psittaci namely the history, taxonomy, morphology, reproductive cycle, metabolism and genetics are reviewed. For the taxonomy in particular, a considerable amount of new information has become available in recent years, following the application of monoclonal antibodies and restriction enzymes. Using these techniques isolates of Chlamydia psittaci from birds have been subdivided in different serovars, a number of isolates have been classified in a new species (Chlamydia pecorum) and isolates from animals have been classified as Chlamydia trachomatis. In the second part of the article, the current knowledge on avian chlamydiosis is summarized. Emphasis is put on clinical signs, lesions, pathogenesis, epizootiology, immunity, diagnosis, prevention and treatment. Also the public health considerations are reviewed. It is concluded that the diagnosis of avian chlamydiosis is laborious and that there is still a need for more accurate, simple and rapid diagnostic tools, both for antigen and antibody detection in various species of birds.

Animals↗
PubMed1979

Frequency selectivity in bird and man: a comparison among critical ratios, critical bands and psychophysical tuning curves.

The relative frequency selectivity of the internal auditory filters, as measured by critical bands or critical ratios, and psychophysical tuning curves, was compared in an avian species (parakeet) and human listeners. The results indicate that the critical band predicts the frequency selectivity of psychophysical tuning curves and vice versa. These findings suggest that there are similar mechanisms which contribute to the frequency selectivity measured by these two procedures and that these mechanisms operate in both the human and avian ear.

Adult↗
PubMed1980

Forward and backward auditory masking in the parakeet (Melopsittacus undulatus).

Backward, foward and simultaneous masking of brief tone pulses was examined in four parakeets. The pattern of non-simultaneous masking in parakeets is quite similar to that observed in humans with rates of threshold recovery faster for backward compared to forward masking conditions. These results may have relevance for the design of vocal signals and the coding of species-specific information in parakeets.

Animals↗
PubMed2004

Wound healing and management in psittacine birds.

Psittacines and other companion avian species often develop wounds requiring some form of medical or surgical therapy. Advancing technology in the field of wound care and management continues to evolve for use by the veterinary clinician. Although not all wounds can be successfully treated, many can be reduced and minimized with therapy. Consideration of the overall health, management, and nutrition of the avian patient will also aid in wound management. The avian patient with normal immune function and optimal nutrition will have improved wound healing compared with an immunocompromized or malnourished patient. The duration of treatment and potential stress of the wound-management program should also be taken into consideration when selecting a treatment program for the avian patient.

Animals↗
PubMed2006

Common procedures in psittacines.

General techniques performed on psittacine birds are described in this article, including restraint, handling, and grooming. Procedures to collect diagnostic samples and to administer therapeutic agents are detailed, including fluid therapy and nutritional support.

Animals↗
PubMed2006

Vitamin A toxicosis in a lorikeet flock.

Vitamin A toxicosis has recently been recognized as a concern for granivorous birds such as cockatiels (Nymphicus hollandicus) and nectarivorous birds such as lorikeets. Such birds have little exposure to performed vitamin A in their wild diet, relying on carotene conversion to supply their vitamin A needs. Multiple clinical problems arose in a lorikeet flock when excessive vitamin A supplementation was used.

Animal Feed↗
PubMed2004

Avian circovirus diseases: lessons for the study of PMWS.

The diseases associated with psittacine beak and feather disease virus (BFDV), pigeon circovirus (PiCV) and goose circovirus (GoCV), which can be classified with porcine circovirus type 2 (PCV2) as members of the genus Circovirus of the family Circoviridae, have clinico-pathological features in common with post-weaning multisystemic wasting syndrome (PMWS), with which PCV2 infection is causally associated. Intracytoplasmic botryoid inclusions within macrophages and depletion of T and B lymphocytes are common histopathological features, and, in each case, affected animals usually exhibit ill-thrift and a predisposition to secondary infections, that is suggestive of an underlying immunosuppression. Although these avian diseases have been the subjects of relatively little research, their study can provide directly applicable lessons in the areas of diagnosis, epidemiology, pathogenesis and disease control for those charged with investigating PMWS. In keeping with its taxonomic separation as the only member of the genus Gyrovirus, the disease caused by chicken anaemia virus (CAV) differs histopathologically from the other circovirus-associated diseases. Most notably, the target cells of CAV have been identified as haemocytoblasts and precursor T lymphocytes, with lymphocyte depletion, which affects T cells only, occurring in cells directly infected with the virus. Nonetheless, CAV is the best-researched circovirus and provides excellent examples of both virus-induced immunosuppression and virus-virus interactions. The study of CAV-induced disease can therefore provide valuable, if less directly applicable lessons.

Animals↗