Oxygen concentration and asexual development of Eimeria tenella in cell cultures.

Primary chicken kidney cells in Flexiperm cultures were either inoculated with Eimeria tenella sporozoites or incubated as noninoculated controls. Oxygen concentration was reduced (10 or 15 vol% O2, 5 vol% CO2) or increased (25 or 30 vol% O2, 5 vol% CO2) in a triple gas incubator (Heraeus B 5061 EK/O2) and retained in a CO2-air incubator (20 vol% O2, 5 vol% CO2) 24 hours post inoculation (hpi). Mature second generation schizonts (mS2) were counted microscopically at 120 hpi and numbers were compared either as mS2 or mS2/cm2 confluent cells. Asexual development of Eimeria tenella was neither stimulated nor inhibited by different oxygen concentrations, indicating that higher numbers of schizonts in cultures under reducing conditions reported earlier are probably a result of increased invasion rates of sporozoites.

Clinical selection criteria for secondary examinations of the health-status of broiler flocks.

Results of post-mortem and laboratory examinations of broilers sampled randomly or selected by clinical symptoms were compared. The male:female-ratio was in all cases nearly equal for randomly sampled and selected birds. Regarding post-mortem findings, differences dependent on selection criteria were observed: in randomly-sampled birds the frequency of breast-blisters and plantar inflammations was higher than in selected broilers, whereas in the latter osteodystrophy and bursal atrophy were seen more frequently. Alterations of joints and tendon-sheaths caused by a reovirus-arthritis in one flock were seen in same frequency in randomly sampled and selected birds, respectively. Parasitological examinations revealed the highest coccidial lesion scores in selected birds with lameness or slightly retarded growth but when dwarfism birds were included into calculations, there was no significant difference among both groups. Results of bacteriological and serological examinations showed no differences between the groups.

[Diseases and causes of death in native wild birds--a literature review]. / Krankheiten und Todesurachen bei einheimischen Wildvögeln--Eine Literaturübersicht.

Little attention was dedicated to diseases and causes of death of indigenous wild birds compared to poultry until recent decades. The interest of veterinary medicine in the spectrum of causes of morbidity and mortality of wild birds increased with the understanding of the importance of these birds as vectors in the epidemiology of zoonoses and as a biological indicator for the occurrence of substances noxious for the environment. The climate as a natural factor and the influences of civilization as traffic, high voltage lines and oil contamination of the sea lead to a reduction of bird species by starvation, traumata, intoxication and degenerative or proliferative and inflammatory or non inflammatory processes. Many parasitological, bacteriological, mycotic and viral diseases are wide spread among free living birds and make difficulties in keeping and breeding endangered birds.

[Clinical diagnosis and differential diagnosis in ornamental birds]. / Zur klinischen Diagnostik und Differentialdiagnostik bei Ziervögeln.

Clinical diagnosis in companion birds consists of well established procedures such as case history, clinical observation, physical examination and further special investigations, e.g. radiology, endoscopy or clinical chemistry. Also some peculiarities of the numerous bird species have to be taken into consideration. These are, for example, certain characteristics of the different species, the varieties of husbandry and environment as single caged birds or flocks in zoos and aviaries and, especially, the lack of typical clinical symptoms in most cases. In regard to those aspects, case history concerning aspects such as age, sex, feeding or course of the disease and special investigations in the case of single caged birds and diagnostic dissections and etiological laboratory examinations, e.g. microbiology, parasitology and toxicology, in the case of flock problems are of major significance. Examples of differential diagnosis in single caged birds, e.g. abnormal behaviour ("feather plucking"), gout, intestinal foreign bodies, tumors or pneumomycosis, and flock health problems, e.g. acariasis, canary pox, coccidiosis or bacterial infections complete this paper.

[Subclinical coccidiosis in broilers and pullets]. / Subklinische Kokzidiosen bei Broilern und Junghennen.

In the period from 1985 to 1987, 24 broiler crops (12 houses; one integration and 3 farms) and 9 pullet flocks (9 houses, 4 farms) were examined for parasites. Intestinal lesion scores and the number of parasites in the intestinal lumen (semiquantitative estimation) were recorded, and the Eimeria species determined when possible (broilers crops: 3rd and 5th week, pullet flocks 4th, 8th, 12th and 18th week). Additionally, the quantity of parasites in litter or faecal samples was examined in regular intervals. Clues for economic damage were only found in broiler crops with increased numbers of coccidial oocysts per gram litter in the 5th week of the fattening period. Eimeria tenella and E. acervulina were the dominating species in broiler chickens and also pullets, E. maxima oocysts however were only casual findings. No ectoparasites, helminths or other protozoa than Eimeria were observed. With regard to the intestinal lesions and the quantities of parasites in the intestine no significant differences were seen when comparing selected broiler chicks and birds taken at random. In pullet flocks the examination of random samples was the superior method, because only freshly dead bodies, collected in insufficient numbers, were suitable for diagnostics. In 3 broiler crops and one flock of replacement pullets kept on a wired floor no Eimeria were diagnosed.

Occurrence of Aeromonas hydrophila in wild birds.

Aeromonas hydrophila was isolated from 135 of a total of 1226 wild birds. It was the only bacterial species in eight birds, while other bacteria, mainly enterobacteriaceae, staphylococci and/or streptococci were identified in all other birds. The rate of isolation from aquatic birds (18.5%) was higher (P<0.001) than from birds of terrestrial habitats (3.4%). Infection may also depend on dietary habits: 7.0% of the granivorous and herbivorous species, 8.4% of the omnivores and 12.0% of carnivorous and insectivorous birds were infected. A. hydrophila was isolated more frequently during the summer (12.9%) than the winter (8.9%).

[Comparative studies of paramyxovirus isolates from wild birds]. / Vergleichende Untersuchungen an Paramyxovirus-Isolaten aus Wildvögeln.

As a result of a surveillance programme in North-Germany, paramyxovirus-isolates of serogroup 1 with different pathogenicity were isolated from different species of feral birds (Black-headed gull, mallard, tawny owl, tree sparrow, mute swan). In chick embryo fibroblast monolayers these isolates produced plaques exhibiting different plaque morphology. After cloning the isolates, further physicochemical, serological and pathogenicity testings were performed. On the basis of mean death time and intracerebral pathogenicity index, two of the isolates were found to be avirulent (lentogenic), whereas the others proved to be virulent (velogenic). SDS-Polyacrylamide-gel-electrophoresis showed polypeptide patterns similar to that of the PMV-1 reference strains. Summarizing all relevant findings of these investigations under consideration of the suggestions for the virological description of avian PMV (Alexander, 1987; Alexander et al., 1987; Who-Expert-Committee, 1980), including the recently established serotyping by means of monoclonal antibodies, the following designations of the PMV isolates tested herein are proposed: 1. PMV-1/black-headed gull/Germany/SSP-233/83, lentogenic NDV, monoclonal antibody group G 2. PMV-1/mallard/Germany/SSP-284/83, lentogenic NDV, monoclonal antibody group H 3. PMV-1/tawny owl/Germany/SSP-262/84, velogenic NDV, monoclonal antibody group B 4. PMV-1/tree sparrow nestling/Germany/SSP-352/84, velogenic NDV, monoclonal antibody group B 5. PMV-1/mute swan/Germany/SSP-204/85, velogenic NDV, monoclonal antibody group B.

[The occurrence of paramyxoviruses in game birds: epizootiological aspects, characteristics in vivo and in vitro. A review of the literature]. / Vorkommen von Paramyxoviren bei Wildvögeln: Epizootiologische Aspekte, Eigenschaften in vivo und in vitro.--Eine Literaturübersicht.

The recent review is based on recent literature on the epizootiology and on properties of avian paramyxoviruses in vivo and in vitro. Paramyxoviruses are classified according to their pathogenicity (especially serotype 1), in addition to serotyping by means of hemagglutination-inhibition tests and by monoclonal antibody binding assays. Also, neuraminidase-inhibition tests, double-immunodiffusion tests can be performed. Growth properties of the different paramyxovirus-serotypes are accessory techniques to classify paramyxoviruses parallel to the determination of the pathogenicity. Structural polypeptides can be demonstrated in polyacrylamide-electrophoresis, thus leading to a distinction of the different serotypes.

[Hygiene problems with ornamental birds in the household]. / Hygieneprobleme mit Ziervögeln im Haushalt.

Approximately 8 million pet birds are kept in the Federal Republic of Germany. The number of households where these birds are living is insignificantly lower, and the birds are usually kept as singles. Hygienic problems can arise due to the close contact between humans and birds. In view of the different pet birds species originating from different biotopes, specific knowledge is often lacking regarding adequate housing, nutrition and general management. This can result in a decrease of natural resistance and therefore can lead to diseases of those birds. Therapy, performed by a nonveterinarian, usually does not only affect the birds, but also endangers the owners themselves. Especially, the carrier state of newly purchased birds with pathogens hazardous for human health has to be considered. Psittacosis has to be mentioned as one of the major zooanthroponoses deriving from birds. This requires to reconsider governmental measures to cope with this disease including policies of bird import as one of the major reasons for spreading the disease. Better management conditions can extend the life expectation of birds. This might also lower the fluctuation within the pet bird population and therefore biohazards for humans. Therefore, instruction and advice of pet bird-owners are necessary.

Lack of immunostimulatory effect of N-acetyl muramyl-L-alanyl-D-isoglutamine on selected chicken immune functions.

Synthetic N-acetyl muramyl-L-alanyl-D-isoglutamine, syn. muramyl-dipeptide (MDP) was found to be immunostimulatory in several experimental animal species. In order to determine the influence of MDP on the chicken immune response, different doses (0.05-0.2 mg) of this compound were administered to 6-week old chickens, and cellular as well as humoral immune functions were tested. Neither the immune response against sheep red blood cells or Newcastle disease virus (strain Hitchner B 1), nor the ability to reject skin grafts, or to react in the delayed hypersensitivity (tuberculin) test, were affected significantly under the experimental conditions employed. This study reveals little evidence for parallels between the ability of the chicken immune system and the immune system of other animal species examined so far, to develop enhanced immune reactions under the influence of MDP.

Antibodies to egg-drop syndrome 76 virus in wild birds in possible conjunction with egg-shell problems.

Antibodies against egg drop syndrome 1976 (EDS 76) virus (strain 127) were detected with the aid of the haemagglutination inhibition test and virus neutralisation test in serum samples of two out of 381 owls, in one out of four storks, in one out of two swans and in one out of 18 wild geese. The antibody positive two owls and the stork laid eggs with a malformed shell. No antibodies against EDS 76 virus were detected in sera of 16 partridges, 28 pheasants, and 72 birds of prey.

[Immunisation of turkey poults against bordetellosis with an adjuvant vaccine]. / Immunisierung von Putenküken gegen die Bordetellose mit einer Adjuvans Vaccine.

Turkey poults obtained from a commercial source were vaccinated with a water-in-mineral oil vaccine consisting of one part complete Freund's adjuvant and one part of a watery suspension of heat-inactivated Bordetella (B.) bronchiseptica-like organisms. Birds of group A received one dose of vaccine at 4 days of age, group B received one vaccination at 4 days of age and a second vaccination at 27 days of age. The vaccine was injected subcutaneously at the base of the neck. A third group (C) of poults served as a non-vaccinated control and a fourth group (D) as a negative control. At the 41st day of age birds of groups A, B and C were challenged by infraorbital inoculation of viable virulent organisms. Eight days later all birds of groups A, B, C and D were killed and examined for pathological changes and samples from the respiratory tract were cultured for B. bronchiseptica-like organisms. The vaccine produced a reversible tissue reaction of an acceptable degree at the site of inoculation in approximately 30% of the birds after the first vaccination and in most of the birds after the second vaccination. The results of these experiments show that one vaccination at 4 days of age does not give a full protection. However, after two vaccinations full protection could be observed. The vaccine was also effective in increasing the clearance rate of B. bronchiseptica-like organisms from the trachea. Results of cultural examination 8 days post-challenge revealed the presence of viable organisms in 100% of the non-vaccinated birds but only in 50% of the poults immunised once and in only 25% of the birds immunised twice with the oil adjuvant vaccine. Both vaccination and challenge induced the production of agglutinating antibodies against the heat labile antigen of the Bordetella strains used.

Short- and long-term stability studies on four lyophilised and one cell-associated turkey herpesvirus vaccines against Marek's disease of chickens.

One cell-associated and four lyophilised turkey herpesvirus (HVT) vaccines of different manufacturers were investigated comparatively in respect of the stability of their infectivity. All titrations were performed in primary chicken embryo fibroblast cell cultures and repeated seven times. The obtained data were computerised and statistically analysed. The long term stability study employed vaccine ampoules containing only lyophilised HVT. After appropriate storage in a refrigerator (4 degrees C) of all tested vaccine ampoules for 1 year no drop of titre was found. In contrast, storage at room temperature (24 degrees C) resulted in a loss of about 50% of the infectious units of HVT by 4 months. Marked differences between the products of different manufacturers were noted after 4 weeks of storage at 37 degrees or 45 degrees C. The infectivity dropped to values between 1/10 to 1/100 and 1/100 to 1/300, respectively. In the short term stability study cell-associated and lyophilised vaccine virus was resuspended in the manufacturer's diluent and maintained at temperatures of 4 degrees , 24 degrees , 37 degrees and 45 degrees C. The infectious units were titrated at 0, 2, 4, 6, 8 and 24 hours for estimation of the half life of the infectivity of HVT. The half life of infectivity of HVT at 4 degrees C was for three vaccines approximately 5 hours and for two vaccines between 1 and 3 hours. With increase of temperature the loss of infectivity increased resulting in half life times close to 1 hour at 45 degrees C.