Tel.+49 30 838 62261 Fax.+49 30 838 62512
In pigs conditions that cause septiceamia will lead to reduced acitivity, failure to thrive and, consecutively, to a an impaired weight gain of the animals. The ensuing financial losses for the owner are considerable. Searching for causative pathogens by drawing blood cultures, as it is common practice in clinical medicine, is not routinely performed in veterinary medicine. Therefore, the intention of the present work was to develop suitable techniques for drawing sterile venous blood samples in the pig and to gain experience with a commercially available blood culture system. As contamination seriously limits the interpretation of blood cultures, the former was considered a prerequisite for an adequate assessment and a particular focus of the study.As a culture system we used the "Signal-Blutkultursystem" (Unipath, Wesel, Germany) and developed a special sampling technique in 91 healthy animals that served as controls. Samples were preferentially obtained in a supine position from the V jugularis externa through a 1 cm incision of the skin. In piglets and younger animals icing with ethylene spray was sufficient for local anaesthesia. General anaesthesia was considered necessary in adult animals. Venipuncture and injection of the blood into culture bottles could be performed in a clean and dustfree environment using disposable syringes and small-bore needles for single use. In this setting we observed a rate of 5,3% false positive results.Bacteraemia as documented by positive blood cultures could be found in subgroups of animals with osteomyelitis and polyarthritis. Serial cultures demonstrated that animals with osteomyelitis and bone abcesses could not be cured as cultures remained positive at the end of treatment. Animals with polyarthritis could be cured if treatment started early before abcess formation occurred. In this latter group of animals we found fever to be a useful clinical indicator of bacteraemia. No positive culture results could be obtained in animals with, pneumonia. Possibly special culture media will be required to identify the causative organisms of pneumonia in pigs.In conclusion the present study demonstrates that performing blood cultures in pigs is feasible using the techniques described and the "Signal-Blutkultursystem". However, as sterile samples are difficult to obtain and as sterile transfer into the culture bottles is cumbersome, the use of blood cultures in pigs will be limited to the evaluation of septicaemia in high-prized animals or within scientific investigations.