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Blunden, A. S., Smith, K. C., Whitwell, K. E., & Dunn, K. A. (1998). Systemic infection by equid herpesvirus-1 in a Grevy's zebra stallion (Equus grevyi) with particular reference to genital pathology. J Comp Pathol, 119(4), 485–493.
Abstract: A severe multi-systemic form of equid herpesvirus-1 infection is described in an adult zebra stallion. There was multifocal necrotizing rhinitis, marked hydrothorax and pulmonary oedema, with viral antigen expression in degenerating epithelial cells, local endothelial cells and intravascular leucocytes of the nasal mucosa and lung. Specific localization of EHV-1 infection was seen in the testes and epididymides, including infection of Leydig cells and germinal epithelium, which would have facilitated venereal shedding of virus in life. The case provided a unique opportunity to study hitherto undescribed aspects of the pathogenesis of naturally occurring EHV-1 infection in the male equine genital tract. Restriction digests of the isolate demonstrated a pattern similar to that of EHV-1 isolates previously recovered from aborted zebra and onager fetuses.
Keywords: Animals; Animals, Zoo; Epididymis/pathology/virology; Equidae/*virology; Herpesviridae Infections/diagnosis/pathology/*veterinary; Herpesvirus 1, Equid/isolation & purification/*pathogenicity; Lymph Nodes/pathology/virology; Male; Nasal Mucosa/pathology/virology; Pulmonary Edema/pathology; Spleen/virology; Testis/*pathology/virology
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Sanchez-Vizcaino, J. M. (2004). Control and eradication of African horse sickness with vaccine. Dev Biol (Basel), 119, 255–258.
Abstract: African horse sickness (AHS) is an infectious but no-contagious viral disease of equidae with high mortality in horses. The disease is caused by an arthropod-borne double-stranded RNA virus within the genus Orbivirus of the family Reoviridae transmitted by at least two species of Culicoides. Nine different serotypes have been described. The nine serotypes of AHS have been described in eastern and southern Africa. Only AHS serotypes 9 and 4 have been found in West Africa from where they occasionally spread into countries surrounding the Mediterranean. Examples of outbreaks that have occurred outside Africa are: in the Middle East (1959-1963), in Spain (serotype 9, 1966, serotype 4, 1987-1990), and in Portugal (serotype 4, 1989) and Morocco (serotype 4, 1989-1991). Laboratory diagnosis of AHS is essential. Although the clinical signs and lesions are characteristic, they can be confused with those of other diseases. Several techniques have been adapted for the detection of RNA segments, antibodies and antigen. Two types of vaccines have been described for AHS virus. Attenuated live vaccines (monovalent and polyvalent) for use in horses, mules and donkeys, are currently available, as well as a monovalent, serotype 4, inactivated vaccine, produced commercially but no longer available. New vaccines, including a subunit vaccine, have been evaluated experimentally. In this paper a review of the last AHS outbreaks in Spain, occurring during 1987-1990, and affecting the central and south part of the country, is presented. The role that vaccination played for the control and eradication of the disease, as well as other aspects such as climatological conditions, number of vectors and horse management, are also presented and evaluated.
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Turner, J. W. J., Liu, I. K., & Kirkpatrick, J. F. (1996). Remotely delivered immunocontraception in free-roaming feral burros (Equus asinus). J Reprod Fertil, 107(1), 31–35.
Abstract: Regulation of local overpopulations of free-roaming feral equids is in demand worldwide for ecological balance and habitat preservation. Contraceptive vaccines have proven effective in feral horses, which breed seasonally, but no data are available for equids such as the burro, which is reproductively active all year round. In the present study, 27 individually identified female feral burros (Equus asinus) roaming free in Virgin Islands National Park (St John, US Virgin Islands; Lesser Antilles) were remotely treated with pig zonae pellucidae (PZP) vaccine. Between January and May, 16 burros were darted with a 1 ml emulsion of PZP plus Freund's adjuvant. Ten to twelve months later each treated burro was given a single booster injection of PZP plus adjuvant to maintain contraception through a second year. Eleven adult untreated jennies served as controls. Beginning one year after initial vaccination, these burros were monitored for pregnancy and foal production. Collection of data to determine treatment effect was not begun until 12 months after initial treatment to ensure that pregnancies existing before vaccination were not included. Pregnancy was assessed using previously validated methods for steroid metabolite measurement in fresh faecal samples. None of the PZP-treated burros produced foals between 0 and 12 months after the last inoculation. One PZP-treated burro tested positive for pregnancy at 10 months after the final inoculation. During this same period, six of 11 untreated burros tested pregnancy-positive, and four were observed with foals. There was no difference in pregnancy rates among treated, control and randomly sampled jennies between 12 and 24 months after the last inoculation. The results demonstrate that, in free-roaming feral burros that are reproductively active all year round: (1) burros can be accessed for remotely delivered PZP vaccination; (2) PZP contraception is effective; (3) PZP contraception is reversible; and (4) pregnancy can be reliably detected by faecal steroid analysis.
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Lamoot, I., Callebaut, J., Demeulenaere, E., Vandenberghe, C., & Hoffmann, M. (2005). Foraging behaviour of donkeys grazing in a coastal dune area in temperate climate conditions. Appl. Anim. Behav. Sci., 92(1-2), 93–112.
Abstract: A small herd of donkeys was introduced in a coastal dune reserve `Houtsaegerduinen' (ca. 80 ha) in Belgium, in order to slow down expansion of dominant grass and shrub species. The Houtsaegerduinen is a nutrient poor scrub-dominated dune system with a spatially heterogeneous vegetation pattern. Different aspects of the grazing behaviour (grazing time, bite rate, habitat use, diet composition) of the free-ranging donkeys are described and analysed. Behavioural data (of maximum six adult mares) were collected through continuous focal animal observation in three consecutive years (1998-2001). Temporal variation in grazing time, habitat use and diet composition was determined. During daylight, donkeys spent most of their time on grazing (56%). In all 3 years, grazing time was significantly shorter in summer (45% of their time), longest grazing times were achieved in spring (64%). In spring, the donkeys also achieved the highest bite rate (21.5 bites/min). The grassy habitat was preferred for foraging in all seasons, while the use of scrub and woodland was variable over time. Averaged over the four seasons, the general diet consisted for 80% of graminoids, 10% of forbs and 10% of woody plants. However, diet composition varied not only among seasons and years, but depended also on the foraged habitat type. We discuss the possible role of the donkeys in nature management.
Keywords: Grazing behaviour; Habitat use; Donkey; Equid; Diet composition
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Lamoot, I., Callebaut, J., Degezelle, T., Demeulenaere, E., Laquiere, J., Vandenberghe, C., et al. (2004). Eliminative behaviour of free-ranging horses: do they show latrine behaviour or do they defecate where they graze? Appl. Anim. Behav. Sci., 86(1-2), 105–121.
Abstract: In contrast to horses in pastures, it is thought that free-ranging horses do not perform latrine behaviour, i.e. a behavioural pattern whereby the animals graze and defecate in separate areas. However, few studies deal with this particular subject, reporting contrasting conclusions. We hypothesize that horses free-ranging in large heterogeneous areas do not perform latrine behaviour. Thus, we believe that grazing and elimination behaviour are spatially related: where horses graze, they will also defecate. Behavioural data were collected from Konik horses, Haflinger horses, Shetland ponies and donkeys, grazing in different nature reserves (54-80 ha). Data for the different equids were analyzed separately, as well as data for mares and stallions (Konik and donkey stallions only). We investigated the proportion of the number of defecations/urinations while grazing on the total number of defecations/urinations; furthermore, we searched for the sequence of behaviours representing latrine behaviour in the strict sense. Additionally, we analyzed the correlation between grazing behaviour and eliminative behaviour on both vegetation type level and patch level. All the female equids often continued grazing while defecating. During urination, grazing ceases in the majority of instances. Cases where a mare terminated grazing in a certain vegetation type and sward height to eliminate in another vegetation type or in another sward height within the same vegetation type were rarely observed. On the vegetation type level as well as on the patch level, there was a highly significant (P<0.001) positive correlation between grazing time and number of eliminations (or eliminating time). The high values of the correlation coefficients (in case of the defecation variables r ranges between 0.553 and 0.955; in case of the urination variables r ranges between 0.370 and 0.839) illustrate that the spatial distribution of the eliminative behaviour can be explained to a high degree by the spatial distribution of the grazing behaviour. Results in the case of the stallions are preliminary, but indicate the same pattern. Horses, free-ranging in large heterogeneous areas, do not perform latrine behaviour, but defecate where they graze. Possibly, animal density is of major importance to explain this behavioural difference with horses in pastures. We suggest that also spatial vegetation heterogeneity and plant productivity of the grazed area, as well as parasite status of the grazing animals could play a role.
Keywords: Equids; Faeces avoidance; Grazing behaviour; Spatial differentiation; Urine; Horse marking
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h:, M., Lévy, F., Fortin, M., Leterrier, C., & LansadLansade, L. (2013). Stress and temperament affect working memory performance for disappearing food in horses, Equus caballus. Animal Behaviour, 86(6), 1233–1240.
Abstract: In the present study, we sought to determine the influence of stress and temperament on working memory for disappearing food in horses. After assessment of five dimensions of temperament, we tested working memory of horses using a delayed-response task requiring a choice between two food locations. Delays ranging from 0 to 20 s were tested. The duration of working memory for disappearing food was first characterized without stressors (N = 26). The horses were then divided into two groups and their performance was assessed under stressful (exposure to acute stressors prior to testing, N = 12) or control conditions (N = 12). Results showed that the duration of working memory for disappearing food lasted at least 20 s under nonstressful conditions, and that under stressful conditions this duration lasted less than 12 s. This stress-induced impairment confirms in a nonrodent species that working memory performance is very sensitive to exposure to stressors. In addition, working memory performance in horses is influenced by the temperamental dimension of fearfulness according to the state of stress: fearful horses showed better performance under control conditions and worse performance under stressful conditions than nonfearful horses. These findings are discussed in the context of the Yerkes–Dodson law of stress and performance.
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Thackeray, J. F. (1988). Zebras from wonderwerk cave, northern Cape province, South Africa: attempts to distinguish Equus burchelli and E. quagga. Suid- Afrikaanse Tydsskrif vir Wetenskap, 84, 99–101.
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[No authors listed]. (2006). African horse sickness--a serious disease (Vol. 84).
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Boyd, L., & Bandi, N. (2002). Reintroduction of takhi, Equus ferus przewalskii, to Hustai National Park, Mongolia: time budget and synchrony of activity pre- and post-release. Appl. Anim. Behav. Sci., 78(2-4), 87–102.
Abstract: A harem of takhi (Equus ferus przewalskii) was observed during introduction to the Hustain Nuruu Steppe Reserve of Mongolia. The goals were to examine whether the harem exhibited significant behavioural synchrony, whether release had an effect on time budget, and what the implications might be regarding acclimatisation to the wild. Behaviours were scan sampled every 10 min between the hours of 06:00 and 22:00, twice before release, twice immediately after release, and twice 2 years after reintroduction. Time budgets were constructed from these data. Considerable behavioural synchrony was evidenced both before and after release. Crepuscular grazing and midday resting were typical, regardless of the date relative to release. Upon release, the amount of time spent moving doubled for all age classes. It is suggested that this increase resulted from exploration. The amount of time spent grazing and standing remained unchanged; the increased amount of time spent moving came at the expense of resting. Two years later, the horses still spent more time moving than when captive. Somewhat less time was spent grazing, although the difference was not significant. More time was spent resting in 1996 than immediately after release. These time budgets provide evidence of successful acclimatisation to the wild. Trekking between favoured sites could account for the persistent increase in time spent moving, with concomitantly less time needed to meet nutritional needs by grazing and more time available for resting. Housing captive takhi in large enclosures is evidently insufficient to permit the amount of movement exhibited by this wild harem. The time budget of the 1- and 2-year olds was more similar to that of adults than foals, indicating approaching adulthood. That 1- and 2-year olds were nursed, without loss of body condition by the dam, provided additional evidence that the takhi achieved excellent nutritional status in the wild.
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Zharkikh, T. L., & Andersen, L. (2009). Behaviour of Bachelor Males of the Przewalski Horse (Equus ferus przewalskii) at the Reserve Askania Nova. Zoologische Garten, 78(5-6), 282–299.
Abstract: The aim of this study was to investigate social relationships between Przewalski horses at a high density in a bachelor group housed in a 3.5-ha enclosure. The group consisted of 16 males aged 5 to 16. Behavioural data were collected during 18 days, total 216 h. Fifteen minute focal animal sampling was used; each horse was observed three times a day for a total of 45 min. The occurrence of 25 behaviours was recorded, and group spacing behaviour was studied using nearest neighbour recordings. The group divided into four subgroups; this supports earlier findings of bachelor groups (n>=10) dividing into two or more subgroups if they included several males aged >5 years. The total frequency of social interactions was 14.6±1.1 h-1. Although the density of the group in this study was higher than in other zoos, the males interacted agonistically only 3.6 h-1. The most frequently observed social behaviour categories were friendly interactions. This study shows possibilities to use some investigative behaviours (marking, flehmen, olfactory investigation, etc.) as indicators of social status of animals in a group.
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