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Westerduin, F. E., Lankveld, D. P. K., van der Velden, M. A., Back, W., & Sloet van Oldruitenborgh-Oosterbaan, M. M. (2003). [Splenectomy in a dressage pony: end of sports career?]. Tijdschr Diergeneeskd, 128(13), 406–411.
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.
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West, R. E., & Young, R. J. (2002). Do domestic dogs show any evidence of being able to count? Anim. Cogn., 5(3), 183–186.
Abstract: Numerical competence has been demonstrated in a wide range of animal species. The level of numerical abilities shown ranges from simple relative numerousness judgements to true counting. In this study we used the preferential looking technique to test whether 11 pet dogs could count. The dogs were presented with three simple calculations: “1+1=2”; “1+1=1”; and “1+1=3”. These calculations were performed by presenting the dogs with treats that were placed behind a screen that allowed manipulation of the outcome of the calculation. When the dogs expected the outcome they spent the same amount of time looking at the result of the calculation as they did on the initial presentation. However, when the result was unexpected dogs spent significantly longer looking at the outcome of the calculation. The results suggest that the dogs were anticipating the outcome of the calculations they observed, thus suggesting that dogs may have a rudimentary ability to count.
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Werth E,. (1929). Zur Abstammung des Hausesels. Sitzungsber Ges Naturforsch Freunde, , 1–3, 342–355.
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Werner, C. W., Tiemann, I., Cnotka, J., & Rehkamper, G. (2005). Do chickens (Gallus gallus f. domestica) decompose visual figures? Anim. Cogn., 8(2), 129–140.
Abstract: To investigate whether learning to discriminate between visual compound stimuli depends on decomposing them into constituting features, hens were first trained to discriminate four features (red, green, horizontal, vertical) from two dimensions (colour, line orientation). After acquisition, hens were trained with compound stimuli made up from these dimensions in two ways: a separable (line on a coloured background) stimulus and an integral one (coloured line). This compound training included a reversal of reinforcement of only one of the two dimensions (half-reversal). After having achieved the compound stimulus discrimination, a second dimensional training identical to the first was performed. Finally, in the second compound training the other dimension was reversed. Two major results were found: (1) an interaction between the dimension reversed and the type of compound stimulus: in compound training with colour reversal, separable compound stimuli were discriminated worse than integral compounds and vice versa in compound training with line orientation reversed. (2) Performance in the second compound training was worse than in the first one. The first result points to a similar mode of processing for separable and integral compounds, whereas the second result shows that the whole stimulus is psychologically superior to its constituting features. Experiment 2 repeated experiment 1 using line orientation stimuli of reversed line and background brightness. Nevertheless, the results were similar to experiment 1. Results are discussed in the framework of a configural exemplar theory of discrimination that assumes the representation of the whole stimulus situation combined with transfer based on a measure of overall similarity.
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Werner, C., & Rehkämper, G. (2001). Categorization of multidimensional geometrical figures by chickens (Gallus gallus f. domestica): fit of basic assumptions from exemplar, feature and prototype theory. Anim. Cogn., 4(1), 37–48.
Abstract: Five hens, experienced in discrimination of two categories of multidimensional geometrical figures presented in fixed pairs in a simultaneous discrimination, were tested with familiar figures arranged as new pairs to assess the dependence of categorization performance on learned relational or configural cues. Test performance did not differ from training: relational or configural cues still influenced discrimination performance. It was suggested that – in accordance with exemplar theories – this influence depended on differences between pairs of probe exemplars that facilitate retrieval of learned category members. To test whether exemplar, feature or prototype theory was most suitable to explain categorization by chickens, the rates of pecking at exemplars were analysed using principal components analysis (PCA). The distribution of the exemplars' component loads on the single component obtained was examined in the light of the conditions dictated by the three types of theories on how representative category exemplars should be. The least constraining theory, i.e. the exemplar theory, was most suitable. Defining factors of classificatory behaviour are discussed with a special emphasis on the characteristics of category-defining stimulus attributes.
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Werner, C. W., & Rehkämper, G. (1999). Discrimination of multidimensional geometrical figures by chickens: categorization and pattern-learning. Anim. Cogn., 2(1), 27–40.
Abstract: Japanese bantam hens were trained to discriminate between geometrical figures varying along four integral dimensions. Only one dimension predicted food: selections of sharp-cornered figures were reinforced, while selections of rounded figures were not. In experiment 1, hens were subsequently trained to discriminate between nine figure pairs in a simultaneous discrimination task. Because single pairs contained multiple redundant cues, whereas the relevant dimension was obvious only across stimulus pairs, the results revealed effects of both generalization and reversal learning. Accordingly, learning speed was enhanced for later discriminations. Experiment 2 tested the hens“ transfer performance to unknown pairs, following experience of 9 or 18 figure pairs. Four of seven hens showed reliable transfer after experience with 9 figures, but only three showed transfer after experience with 18 figures, indicating lower transfer with higher number of stimulus pairs learned. In experiment 3, hens were trained to discriminate 27 figure pairs. Discrimination ratios further decreased and the groups of pairs differed significantly in their ratios of discrimination. Individual hens” pecking behaviour was analysed in relation to each dimension of single figures and in relation to relative differences in the levels of dimensions between paired figures. Hens were shown to be oriented towards irrelevant information and more towards relational and configurational than elemental and dimensional aspects. The results are discussed in the biological context of individual recognition in chickens" dominance hierarchies, in which we suppose that chickens identify individual flock mates by representation of their visual pattern rather than by single characteristics.
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Werhahn, H., Hessel, E. F., & Van den Weghe, H. F. A. (2012). Competition Horses Housed in Single Stalls (II): Effects of Free Exercise on the Behavior in the Stable, the Behavior during Training, and the Degree of Stress. Journal of Equine Veterinary Science, 32(1), 22–31.
Abstract: Although housing horses in single stalls limits their natural behavior to a great extent, this housing system is widespread in Germany, especially for competition horses. To improve the welfare of this system, free exercise on pastures or paddocks is deemed suitable, but it is also feared because of injuries and decreased willingness or motivation to perform. In the present study, three treatments were investigated with regard to their effect on the behavior of six competition horses in the stable, behavior during training, and on their degree of stress: daily training without free exercise (no turnout [NT]), solitary turnout for 2 hours after training, and 2-hour turnout in groups of two after training (group turnout). The horses' behavior in the stable was continuously analyzed through video recordings (2 pm to 6 am) on 3 days at the end of each treatment. The degree of stress was evaluated daily by heart rate variability at rest. The behavior during training was evaluated by a questionnaire answered by the riders, and the distance covered during training was measured by global positioning system. When NT was allowed, the horses showed less lying in the stable compared with the treatments with turnout. Heart rate variability measurements resulted in great individual differences, but generally, there was a higher degree of stress shown with the treatment NT according to the following parameters: standard deviation of inter-beat-intervals (SDNN), square root of the mean of the sum of the squares of differences between successive inter-beat-intervals (RMSSD), and ratio between low frequency and high frequency (LF/HF). The willingness to perform was evaluated as being slightly better in the treatments with turnout than in the treatment without turnout.
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Wennerstrand, J., Johnston, C., Roethlisberger-Holm, K., Erichsen, C., Eksell, P., & Drevemo, S. (2004). Kinematic evaluation of the back in the sport horse with back pain. Equine Vet J, 36(8), 707–711.
Abstract: REASONS FOR PERFORMING STUDY: Earlier studies have developed a clinical tool to evaluate objectively the function of the equine back. The ability to differentiate horses with back pain from asymptomatic, fully functioning horses using kinematic measures from this tool has not been evaluated. OBJECTIVES: To compare the kinematics of the back at walk and trot in riding horses with back dysfunction to the same parameters in asymptomatic sport horses. METHODS: The kinematics of the back in 12 horses with impaired performance and back pain were studied at walk and trot on a treadmill. Data were captured for 10 sees at 240 Hz. Range of movement (ROM) and intravertebral pattern symmetry of movement for flexion and extension (FE), lateral bending (LB) and axial rotation (AR) were derived from angular motion pattern data and the results compared to an earlier established database on asymptomatic riding horses. RESULTS: At walk, horses with back dysfunction had a ROM smaller for dorsoventral FE in the caudal thoracic region (T13 = 7.50 degrees, T17 = 7.71 degrees; P<0.05), greater for LB at T13 (8.13 degrees; P<0.001) and smaller for AR of the pelvis (10.97 degrees; P<0.05) compared to asymptomatic horses (FE-T13 = 8.28 degrees, FE-T17 = 8.49 degrees, LB-T13 = 6.34 degrees, AR-pelvis = 12.77 degrees). At trot, dysfunctional horses had a smaller (P<0.05) ROM for FE at the thoracic lumbar junction (T17 = 2.46 degrees, L1 = 2.60 degrees) compared to asymptomatic horses (FE-T17 = 3.07 degrees, FE-L1 = 3.12 degrees). CONCLUSIONS: The objective measurement technique can detect differences between back kinematics in riding horses with signs of back dysfunction and asymptomatic horses. The clinical manifestation of back pain results in diminished flexion/extension movement at or near the thoracic lumbar junction. However, before applying the method more extensively in practice it is necessary to evaluate it further, including measurements of patients whose diagnoses can be confirmed and long-term follow-ups of back patients after treatment. POTENTIAL RELEVANCE: Since the objective measurement technique can detect small movement differences in back kinematics, it should help to clinically describe and, importantly, objectively detect horses with back pain and dysfunction.
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Weng, R. C., Edwards, S. A., & English, P. R. (1998). Behaviour, social interactions and lesion scores of group-housed sows in relation to floor space allowance. Appl. Anim. Behav. Sci., 59(4), 307–316.
Abstract: The space allowance appropriate for sows in group housing remains scientifically undefined, since the social space requirement of a group of animals and the factors which affect this are unknown. Eight established groups of six pregnant, multiparous sows were used in a replicated Latin Square design of experiment, with 7 day periods, to compare four pen sizes providing 2.0, 2.4, 3.6 or 4.8 m2/sow. For the last 48 h of each 7 day period, a continuous video recording was made to determine general behaviour and all social interactions. Time spent rooting increased progressively with increasing space allowance, whereas time spent sitting and standing inactive were both progressively reduced. The total frequency of social interactions and aggressive behaviour both increased with decreasing space allowance. The Attack:Retreat ratio was significantly higher, and the Avoidance Index significantly lower, in the smallest pen. All body regions had the highest count of lesions after sows had been in the smallest pen, with damage levels being reduced as pen area increased. Analysis of body lesion scores, combining incidence and severity, gave the same treatment effects. In conclusion, the results indicated that a minimum space of between 2.4 and 3.6 m2/sow was necessary in the conditions of this experiment to promote good welfare. This result cannot be generalised to situations of different group size, group stability or feeding method.
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Wemelsfelder, F. (2001). The Inside and Outside Aspects of Consciousness: Complementary Approaches to the Study of Animal Emotion. Animal Welfare, 10, 129–139.
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