Abstract: A 14-year-old Arabian cross-bred gelding was referred to the University Clinic because of mild, recurrent signs of colic for 5 days. The pony showed icteric mucous membranes, haemolytic blood, and dark coloured urine. Internal examination did not give a clear diagnosis. Unidentified intra-abdominal strands were found and haemorrhagic abdominocentesis led to the decision to perform an exploratory laparatomy. An extremely enlarged spleen was the sole finding. A splenal biopsy sample was taken and surgery was completed. The pony remained colicky, so the spleen was examined by ultrasonography. After this examination, the tentative diagnosis 'tumour of the spleen' was made and splenectomy was performed. Pathological examination of the spleen revealed splenomegaly caused by infarctions of unknown origin. Eight weeks after surgery, the pony started again in dressage competition. Six months after splenectomy, the pony won the provincial dressage competition.

Abstract: 'Rollkur' or 'overbending' is the low and deep riding of a dressage horse during training or warming up. Lately, this technique has been criticized, and not necessarily objectively, on welfare grounds. To be able to evaluate these criticisms, more needs to be known about the workload and stress of horses being ridden 'rollkur'. The aim of the present study was to compare the workload of eight riding-school horses when being ridden deep and round with a draw rein ('rollkur') and when being ridden in a natural frame with only light rein contact ('free'). Workload (as measured by heart rate and blood lactate concentration) was slightly higher when horses were ridden 'rollkur' than when they were ridden 'free'. There were no differences in packed cell volume, or glucose and cortisol concentrations. No signs of uneasiness or stress could be determined when the horses were ridden 'rollkur'. Subjectively, all horses improved their way of moving during 'rollkur' and were more responsive to their rider.

Abstract: 1. Models on territory acquisition and tenure predict that territorial animals benefit by adjusting territorial defence behaviour to previous challenges they had experienced within the socially complex environment of communication networks. 2. Here, we addressed such issues of social cognition by investigating persisting effects of vocal contests on territory defence behaviour in nightingales Luscinia megarhynchos (Brehm). 3. Using interactive playback during nocturnal song of subjects, a rival was simulated to countersing either aggressively (by song overlapping) or moderately (by song alternating) from outside the subjects' territory. Thereby, the time-specific singing strategy provided an experimentally controlled source of information on the motivation of an unfamiliar rival. 4. Expecting that nightingales integrate information with time, the same rival was simulated to return as a moderately singing intruder on the following morning. 5. The results show that the vigour with which male nightingales responded to the simulated intrusion of an opponent during the day depended on the nature of the nocturnal vocal interaction experienced several hours before. 6. Males that had received the song overlapping playback the preceding night approached the simulated intruder more quickly and closer and sang more songs near the loudspeaker than did males that had received a song alternating playback. 7. This adjustment of territory defence strategies depending on information from prior signalling experience suggests that integrating information with time plays an important part in territory defence by affecting a male's decision making in a communication network.

Abstract: INTRODUCTION: The connection between morphologic changes of the spine and the intensity of training has been assessed for a number of sport activities. The influence of horseback riding on the spine has only rarely been evaluated. The aim of our study was to evaluate to what degree horseback riders suffer from back pain and whether there is an association between this parameter and the category i. e. the intensity of horseback riding. Furthermore we wanted to judge whether riding may have a positive effect on pre-existent back pain. METHODS: 508 horseback riders (63.2 % females; 36.8 % males) competing in either dressage, showjumping or vaulting were interviewed using a questionnaire. Apart from biometric data, the intensity with which riding was performed and the localisation and intensity (VAS) of back pain was assessed. Furthermore, in the case of existing back pain, riders were asked whether different riding disciplines and paces changed the intensity of pain. RESULTS: 300 dressage riders (59.1 %), 188 showjumpers (37.0 %) and 20 vaulters (3.9 %) with an average age of 33.5 Jahre (12 – 77 years) were questioned. The incidence of back pain was 72.5 %. A significant correlation between back pain and riding discipline respectively gender or riding level could not be found. Discrepancies in VAS-score for dressage riders (3.95 +/- 0.13), show jumpers (4.10 +/- 0.16) and vaulters (3.76 +/- 0.5) were marginal and not significant (p > 0.05). Overall 58.7 % resp. 15.2 % reported to have pain in the lumbar i.e cervical spine. Despite the fact that a large fraction of dressage riders claimed to have problems in these spine areas with 57.7 % resp. 68.8 %, this finding was not significant compared to the other riding disciplines. While 61.6 % of dressage riders reported an improvement of their back pain when riding, this was only the case in 40.9 % of show jumpers. CONCLUSION: Compared to the general population, a high incidence of back pain is found among riders. A significant correlation between the intensity of riding or the riding discipline and frequency or severity of back pain could not be found. For riders with pre-existent back pain the pace “walk” seems to have a positive influence on pain intensity.