Abstract: OBJECTIVE: To determine signalment, history, clinical signs, duration, seasonality, and response to various treatments reported by owners for headshaking in horses. DESIGN: Owner survey. ANIMALS: 109 horses with headshaking. PROCEDURE: Owners of affected horses completed a survey questionnaire. RESULTS: 78 affected horses were geldings, 29 were mares, and 2 were stallions. Mean age of onset was 9 years. Headshaking in 64 horses had a seasonal component, and for most horses, headshaking began in spring and ceased in late summer or fall. The most common clinical signs were shaking the head in a vertical plane, acting like an insect was flying up the nostril, snorting excessively, rubbing the muzzle on objects, having an anxious expression while headshaking, worsening of clinical signs with exposure to sunlight, and improvement of clinical signs at night. Treatment with antihistamines, nonsteroidal anti-inflammatory drugs, corticosteroids, antimicrobials, fly control, chiropractic, and acupuncture had limited success. Sixty-one horses had been treated with cyproheptadine; 43 had moderate to substantial improvement. CONCLUSIONS AND CLINICAL RELEVANCE: Headshaking may have many causes. A large subset of horses have similar clinical signs including shaking the head in a vertical plane, acting as if an insect were flying up the nostrils, and rubbing the muzzle on objects. Seasonality and worsening of clinical signs with exposure to light are also common features of this syndrome. Geldings and Thoroughbreds appear to be overrepresented. Cyproheptadine treatment was beneficial in more than two thirds of treated horses.

Abstract: REASONS FOR PERFORMING STUDY: Studies on the prevalence of behavioural disorders in horses and on associated risk factors have revealed inconsistent results. There are many studies on the neuropharmacological, surgical or mechanical therapy of stereotypies, but little is known about their causation. OBJECTIVES: To explore risk factors associated with the occurrence of behavioural disorders in horses. METHODS: A sample of horse owners, selected randomly and representative for Switzerland, was contacted in a postal survey. Answers were provided for 622 stables (response rate 35.2%). Individual data of 2,341 horses were examined with path analysis (multivariable linear and logistic regression), and adjustment made for possible confounding effects due to age and breed. RESULTS: Out of 60 possible risk factors, 11 were associated with the outcome at the univariable level (null-hypothesis path model) and 3 factors remained after the backward logistic regression procedure. Mature Warmbloods and Thoroughbreds, assessed by the owners to be reactive, fed 4 times a day and without daily pasture, had increased odds of displaying crib-biting, weaving and box-walking. Furthermore, indirect associations of 5 factors with the outcome were identified. CONCLUSIONS: The final logistic regression model of risk factors leads to the hypotheses that causal prevention of stereotypic behaviours should be based upon housing and management conditions which allow tactile contact with other horses (e.g. mutual grooming), daily free movement (paddock or pasture), as well as the provision of high amounts of roughage but of little or no concentrates. POTENTIAL CLINICAL RELEVANCE: It is one of the aims of population medicine to prevent the development of behavioural disorders. Further research is needed to test the concluding hypotheses in experimental studies or to verify them in the context of similar observational studies.

Abstract: Semireserves were created by the European Conservation Project for scientific research in preparation for reintroduction in the wilderness. They are defined as enclosures large enough to carry a group of Przewalski horses throughout the year without any additional feeding. The semireserve offers diverse opportunities for significant scientific research. As part of a general screening program, the hoof development in a group of Przewalski horses was investigated in the semireserve Schorfheide near Berlin. Since the foundation of this semireserve in 1992, veterinary treatment was not necessary with the exception of hoof trimming in two animals in 1993. However, major health problems were encountered in the spring of 1999, when three other mares showed signs of laminitis. The initial diagnosis by the authors and the local veterinary surgeon based on observation of behaviour, gait, stance, walk and trot of three mares whose initial weights were higher than those of the healthy mares. The initial diagnosis was confirmed by palpation and the occurrence of very deep horn rings on all hooves and a laminitic horn ring on the right front hoof of one mare. An adequate laminitic therapy was not possible under the conditions of a semireserve. The applied management aimed at two goals: 1. To reduce endotoxin production and acidosis in the horses by reducing the ingestion of carbohydrate rich food. 2. To reduce the mares level of activity and to prevent tearing of the suspensory apparatus of the coffin bone. To achieve these two goals it was decided to remove the three laminitic mares from the rich pasture in the main part of the semireserve and to confine them onto the poorer pasture of the small separately fenced area. All three affected mares had fully recovered from their laminitic condition. Prevention of grass laminitis can be achieved by the following measures: 1. Reduction in grass intake could be achieved by increasing the grazing pressure by an increase in stocking rate of the horses or mixed grazing with another species such as sheep. 2. A longer term solution to the problem may well be to sow specific varieties of grass with lower concentrations of water soluble carbohydrate.

Abstract: REASONS FOR PERFORMING STUDY: Sandy soil is often mentioned as a risk factor in the development of sand-related gastrointestinal disease (SGID) in the horse. There are other variables, but few studies confirm any of these. OBJECTIVE: To investigate soil type, pasture quality, feeding practice in the paddock, age, sex and body condition score as risk factors for sand intake in the horse. METHODS: Faeces were collected from 211 Icelandic horses on 19 different studs in Denmark together with soil samples and other potential risk factors. Sand content in faeces determined by a sand sedimentation test was interpreted as evidence of sand intake. Soil types were identified by soil analysis and significance of the data was tested using logistic analysis. RESULTS: Of horses included in the study, 56.4% showed sand in the faeces and 5.7% had more than 5 mm sand as quantified by the rectal sleeve sedimentation test. Soil type had no significant effect when tested as main effect, but there was interaction between soil type and pasture quality. Significant interactions were also found between paddock feeding practice and pasture quality. CONCLUSION: To evaluate the risk of sand intake it is important to consider 3 variables: soil type, pasture quality and feeding practice. Pasture quality was identified as a risk factor of both short and long grass in combination with sandy soil, while clay soil had the lowest risk in these combinations. Feeding practice in the paddock revealed feeding directly on the ground to be a risk factor when there was short (1-5 cm) or no grass. Also, no feeding outdoors increased the risk on pastures with short grass, while this had no effect in paddocks with no grass. More than 50% of all horses investigated in this study had sand in the faeces. POTENTIAL RELEVANCE: The identification of risk factors is an important step towards prevention of SGID. Further research is necessary to determine why some horses exhibit more than 5 mm sand in the sedimentation test and whether this is correlated with geophagic behaviour.

Abstract: Anthropophagic horses have been described in classical mythology. From a current perspective, two such instances are worth mentioning and describing: Glaucus of Potniae, King of Efyra, and Diomedes, King of Thrace, who were both devoured by their horses. In both cases, the horses' extreme aggression and their subsequent anthropophagic behaviour were attributed to their madness (hippomania) induced by the custom of feeding them with flesh. The current problem of 'mad cow' disease (bovine spongiform encephalopathy) is apparently related to a similar feed pattern. Aggressive behaviour in horses can be triggered by both biological and psychological factors. In the cases cited here, it is rather unlikely that the former were the cause. On the other hand, the multiple abuses imposed on the horses, coupled with people's fantasies and largely unconscious fears (hippophobia), may possibly explain these mythological descriptions of 'horse-monsters'.