Spatial analysis of the exposure of dogs in rural north-coastal California to vectorborne pathogens

Between 0 and 50 per cent of the dogs in eight rural villages in far northern California with a high risk of tickborne diseases were seropositive for Anaplasma phagocytophilum and Bartonella vinsonii subspecies berkhoffii, and between 0 and 10 per cent were seropositive for Borrelia burgdorferi. The odds ratio for the co-exposure of individual dogs to B vinsonii berkhoffii and A phagocytophilum was 18.2. None of the diseases was associated with the sex of the dogs, whether they slept out of doors, or whether tick-preventive measures were taken. When the villages were assessed for landscape risk factors, a particularly high seroprevalence for B vinsonii berkhoffii and A phagocytophilum was observed in a village at a relatively high altitude and greater distance from the Pacific coast, and montane hardwood conifer woodland was most associated with a high seroprevalence for these two pathogens.     

Culicoides biting midges at the National Zoological Gardens of South Africa

Culicoides biting midges (Diptera: Ceratopogonidae) are responsible for the transmission of a large number of pathogens to livestock and wild animals. In this study the presence of the genus, using light traps based at four different sites within the National Zoological Gardens of South Africa, was investigated during 2002-2004. In total, 37 species were recorded, including large numbers of Culicoides imicola Kieffer, 1913, which is responsible for the transmission of economically important arboviruses in South Africa, Europe, Middle and Far East. These results are discussed with reference to the wider Culicoides fauna in the Onderstepoort area of South Africa, their vector competence as well as biosecurity at the National Zoological Gardens.     

Pharmacokinetics of cefquinome in healthy and Pasteurella multocida‐infected rabbits

The pharmacokinetics of cefquinome were studied in healthy and Pasteurella multocida‐infected rabbits after a single intramuscular (IM) injection at 2 mg/kg of its sulfate salt. Twelve female New Zealand white rabbits (2.0–2.5 kg) were used; six of them served as controls, and the other six had been infected with P. multocida; the experiments were conducted 1–2 days after nasal inoculation of P. multocida when rabbits showed the signs of respiratory infection. Plasma concentrations of cefquinome were determined using high‐performance liquid chromatography. The values of elimination half‐life, area under the curve, area under the first moment curve, and mean residence time were significantly lower in infected rabbits (0.48 hr, 4.54 hr*μg/ml, 3.63 hr* hr*μg/ml and 0.8 hr, respectively) than healthy rabbits (0.72 hr, 9.11 hr*μg/ml, 9.85 hr* hr*μg/ml and 1.1 hr, respectively), whereas total body clearance was significantly higher in infected than healthy rabbits. Therefore, P. multocida infection caused significant changes in some of the pharmacokinetic parameters of cefquinome in rabbits. These pharmacokinetic changes may affect dose regimen when used in P. multocida‐infected rabbits.     

Energy and protein concentration of broiler rations in Cuba. 4. Female broilers in the summer

A total of 1,900 female broilers of the variety White Plymouth Rock was tested with 4 energy concentrations (10.5, 11.5, 12.6 and 13.6 MJ metabolizable energy/kg feed) and 4 protein concentrations (15.0, 17.5, 20.0 and 22.5% CP) in their first 56 days of life in 16 test groups. The animals were kept in cages and were directly exposed to the natural Cuban summer temperatures from their 15th day of life onwards. As every test group was run with 6 repetitions, the results could be variance analytically calculated. In a comparison of male and female broilers in summer one can state that the female animals achieved a lower intake of feed, energy and crude protein as well as a lower live weight than the male animals. In winter the female broilers consumed between 15.7 and 36.4% more feed and achieved a live weight gain between 11.1 and 43% higher than in summer. It could be shown that the maximum live weight of the female broilers could be achieved in summer if rations containing 12.6 MJ metabolizable energy and 20% CP are fed in a one-phase feeding system.     

Exercise-induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. III. Subgross findings in lungs subjected to latex perfusions of the bronchial and pulmonary arteries

Latex was injected under pressure into bronchial and pulmonary arteries of the inflated lungs of Thoroughbreds and transverse sections taken to calculate the area of lesions resulting from exercise-induced pulmonary haemorrhage. Extensive areas of dense brown haemosiderin varying from 0 to 45 per cent of total lung volume were identified, predominantly in the dorsocaudal lungfields. Bronchial arterial proliferation appeared to have replaced the pulmonary supply in affected areas of the lung. Closely associated with the staining and bronchial arterialisation, there was widespread small airway disease. The most severely affected bronchioles contained thick gelatinous or mucous exudate or mucoid plugs and had grossly thickened walls. These lesions suggest that the source of haemorrhage in exercise-induced pulmonary haemorrhage is from alveolar capillaries anomalously supplied by the bronchial arterial circulation through the development of pathological shunts. Small airway disease is suggested as being of major importance in the pathogenesis of the disease and may have led to the initial proliferation of the bronchial circulation.     

The Prevention and Control of Epidemics of Acute Undifferentiated Diarrhea of Beef Calves in Western Canada

It is frequently evident that outbreaks of diarrhea occur in spite of apparent “good management” and “good calving conditions”. This observation underlies the fact that we still do not understand many of the epidemiological factors which contribute to calf diarrhea outbreaks. For example, we still lack biological criteria by which to judge the degree of crowding and the degree of stress. Nevertheless, application of the principles described above will prevent or decrease the severity of many annual epidemics. To be successful, a program of prevention and control should be discussed with producers long before the calving season, preferably during the preceding summer or fall. Implementation of a complete program may take several calving seasons and producers should be made aware that prevention by improved management is an on-going, evolutionary process. More and improved vaccines are becoming available; however, as is the case with most biologicals, their impact cannot be determined until after they have been used for several years. They should be recognized as only one of several managent tools at the disposal of the veterinarian and livestock producer.     

Potential use of lymphocyte blastogenic responses in diagnosis of bovine tuberculosis

A comparison of in vitro lymphocyte responses and delayed type tuberculin skin test responses was made in an animal experimentally exposed to a Mycobacterium bovis-infected animal and in cattle naturally infected with M. bovis. Tuberculin skin tests did not suppress in vitro lymphocyte responses to M. bovis PPD and to M. avium PPD tuberculin. The whole blood test used in these studies provided for considerable savings in time as compared to use of purified lymphocytes for evaluating in vitro cellular responses. Variations in the responsiveness of lymphocytes to specific mycobacterial antigens was observed, therefore, it is recommended that profiles be established using three or more tests conducted at 14-day intervals.