In the present article, a review is given on adenovirosis in pigeons. Aetiology, pathogenesis, clinical signs, lesions, diagnosis and control of two clinical types of pigeon adenovirus infections are described.
-In this study we sequenced and analysed the fimH and fimA genes of 24 avian pathogenic Escherichia coli (APEC) isolates, in order to investigate their possible conserved nature. Additional parameters (serotype, presence of aerobactin receptor, expression of F1 pili and virulence for chickens) were investigated to look for correlations with the obtained sequences. The sequence analysis demonstrated that FimH is highly conserved among all investigated APEC strains (> 99% homology), whereas the major subunit FimA is less conserved, presenting 6 variable regions distributed along the protein. A hydrophilicity analysis suggested several variable domains of FimA to be potential epitopes. We were able to classify the investigated strains into three main groups, on the basis of the amino-acid sequences of the variable regions. This grouping was consistent throughout all variable regions and was independent of serotype, leading to an improved classification of the F1 pili. No correlation was found between the fimH and fimA sequences and the following parameters: avian species, organ of isolation, serotype, presence of aerobactin receptor and virulence for chickens. This study elucidated the molecular structure and the degree of conservation of FimH and FimA among various avian pathogenic E. coli strains. Escherichia coli / avian / APEC / FimH / FimA
ABSTRACT:The present study evaluated under field conditions the efficacy of bacitracin zinc soluble powder (Bacivet S ® ) for the treatment of Epizootic Rabbit Enteropathy (ERE). A blinded study was conducted in compliance with the "Good Clinical Practice" guidance. The trial site was known to be chronically infected with ERE. A total of 384 weaned rabbits (30 days of age) were enrolled in the study. They were randomly distributed over 6 rows of cages located in the same experimental room. Two rows of cages remained untreated (control group), another 2 rows were treated with Bacivet S ® for 14 days (T14) and 2 rows were treated with Bacivet S ® for 21 days (T21). The medication was administered per row via the drinking water and initiated when at least one animal, showing clinical signs of ERE, died. The dose was adjusted daily according to the weight of the rabbits to achieve the target dose of 420 IU/kg body weight in the two treatment groups. Animals were observed daily for mortality, diarrhoea, tympany, or any other abnormal sign for 42 days post enrollment. Weights of the animals and feed intake were recorded on a weekly base. On the second day after the set-up of the trial, mortality already occurred with clear signs of ERE and the medication was initiated. On the primary evaluation parameter, mortality, both treated groups showed significant (P<0.01) better results than the control group with an overall mortality reaching 13.5%, 12.6% and 26.6% in T14, T21 and control groups, respectively. Considering only ERE confirmed mortality, differences were even more pronounced; 4.0% (T14), 6.3% (T21) and 14.1% (control), respectively. The occurrence of clinical signs (tympany and diarrhoea) was also reduced in medicated rabbits but this reduction was markedly higher for T21 treated rabbits (P<0.001 compared to control) than in the T14 group. A few days after the termination of the medication period, moderate mortality and clinical symptoms were observed in both medicated groups. These isolated cases were probably due to a recontamination through the untreated groups. Data of daily weight gain and feed intake showed a good agreement with the observed mortality and clinical symptoms. In conclusion, Bacivet S ® proved its efficacy against ERE in a chronically infected environment for both tested treatment regimens.
AbstrAct:The efficacy of diclazuril in growing rabbits was investigated under experimental and field conditions. In a first experimental trial, the susceptibility of recent isolated French Eimeria field strains to in-feed use of diclazuril, salinomycin and robenidine was studied in fattening rabbits. Rabbits were challenged at the age of 31 d with a mixed inoculum of Eimeria magna, E. media and E. perforans. Production data and oocyst excretion were compared with an infected-untreated control group and an uninfected-untreated control group. Infection resulted in significantly lower production data and higher oocyst excretion in the infected-untreated control group. Salinomycin and diclazuril treated rabbits were able to control the infection, demonstrated also by comparable weight gain and final weight to those of the uninfected-untreated control rabbits and significantly higher than those of the infected-untreated control rabbits. Based on the production data and oocyst excretion, robenidine was not able to control the infection adequately. Economic performance (weight gain, feed intake, feed conversion) and oocyst excretion were significantly worse than in the uninfecteduntreated controls. In a second trial, a 1 yr longitudinal study was carried out in Italy to evaluate the excretion of coccidia in growing rabbits from 8 meat farms applying a 2-phase anticoccidial programme (diclazuril and robenidine). Parasitological parameters (oocyst counts and species identification) were measured monthly. Seven of the 11 known coccidial rabbit species were identified. Variable levels of oocysts per gram were detected in the farms, but on all farms lower oocyst per gram and a reduced number of Eimeria spp. in rabbit faeces were recorded in the 8-mo treatment period with diclazuril.
Recent advances in the epidemiology and control of parasitic gastroenteritis in sheep. Veterinary Record 92,469-473 MCKELLAR, Q. A. & MARRINER, S. E. (1987) Comparison of the anthelmintic efficacy of oxfendazole or ivermectin administered orally and ivermectin administered subcutaneously to sheep during the periparturient period. Veterinary Record 120,383-386
Mycoplasma gallisepticum (M. gallisepticum) remains one of the most important diseases in poultry production. Controlling the impact of the disease is done by eradication of positive breeder flocks or by vaccination and medication. A widely used molecule in medication programs is tiamulin, a pleuromutilin antibiotic. Since recent data on the in vivo efficacy of this molecule are scarce, 2 challenge studies were conducted using a recently isolated M. gallisepticum strain belonging to the wildtype population with regard to its tiamulin and tetracycline minimum inhibitory concentration (MIC). In the first challenge study, the dose rate of tiamulin was tested. For this, broilers were infected with M. gallisepticum and treated with 10 mg or 25 mg tiamulin hydrogen fumarate (hf)/kg body weight (BW) for 5 successive days. In a second challenge study, the dose rate of tiamulin combined with chlortetracycline was tested. For this, broilers were infected with M. gallisepticum and treated with 6.25 mg tiamulin hf/18.75 mg chlortetracycline hydrochloride (hcl)/kg BW or 12.5 mg tiamulin hf/37.5 mg chlortetracycline hcl/kg BW for 5 successive days. Clinical scoring of respiratory signs, macroscopic scoring of respiratory tract lesions, M. gallisepticum isolation from the respiratory organs, weight gain, and mortality were the monitored efficacy parameters. The first study demonstrated that a 5-day 10 mg/kg BW tiamulin hf treatment provided significant protection against the M. gallisepticum infection. However, since the 5-day 25 mg/kg BW group was significantly better than the 10 mg/kg BW for reducing the post-treatment clinical signs and the M. gallisepticum numbers in the respiratory organs, the 25 mg/kg BW treatment is recommended for clinical M. gallisepticum infections. In the second study, the combined 12.5 mg tiamulin hf/37.5 mg chlortetracycline hcl/kg BW resulted in a significant reduction of the severity of clinical respiratory disease post treatment and a significant reduction of the M. gallisepticum numbers in the respiratory tract.
Two killed adjuvanted vaccines were evaluated for their efficacy against salmonellosis in pigeons. Both vaccines contained whole-cell formaldehyde-inactivated Salmonella typhimurium var. Copenhagen bacteria. Two groups of 10 pigeons were inoculated twice with a 3-week interval with one of the vaccines. Ten weeks after the second vaccination, all vaccinated pigeons as well as 10 non-vaccinated birds were challenged by crop inoculation of 10 9 colony-forming units of a Salmonella serotype Typhimurium var. Copenhagen strain. Ten pigeons that were not vaccinated or challenged served as negative controls. As determined by clinical examination, plasma chemistry and necropsy, neither vaccine induced protection against challenge. The only significant effects observed were a reduction in the level of faecal shedding and a less severe polydipsia in the pigeons treated with one of the two vaccines. Results of this study indicate that vaccination against salmonellosis in pigeons with killed vaccines may not be very useful. However, the ability of certain vaccines to reduce shedding may contribute to the control of salmonellosis in infected pigeon lofts.
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