Not published as conference proceedings

In the developed world the control of equid gastrointestinal (GI) nematodes, in particular cyathostomins, is increasingly challenging due the threat of anthelmintic resistance. In developing countries such as Ethiopia despite high parasite burdens, access to genuine anthelmintic treatment is limited. In both situations there is a need for alternative treatment and management regimens for effective parasite control and consequently there has been increasing interest in the use of bioactive plant extracts (BPEs) [1]. This study identified candidate plants in the UK and Ethiopia and evaluated their in vitro efficacy against cyathostomin populations derived from donkeys. A participatory rural appraisal (PRA) approach was used to identify five ethnoveterinary medicines for use in donkeys in Ethiopia. In the UK three plants were identified following extensive review of literature citing efficacy against GI nematodes of other host species and two extracts were provided courtesy of Prof Jerzy Behnke, University of Nottingham. Hydro-alcoholic extraction of dried plant material was carried out for the eight extracts prior to reconstitution in both water and DMSO. Efficacy of each extract was evaluated by egg hatch assay (EHA) and larval migration assay (LMA) using eggs and larvae recovered from the faeces of donkeys at the Donkey Sanctuary, UK. Dose response curves were produced and ED-50 values were calculated using probit analysis. Of the five Ethiopian plant extracts tested, four showed efficacy in the EHA and/or LMA. The two most efficacious were Acacia nilotica and Rumex abyssinicus in the EHA with ED-50 values of 0.72mg/ml and 1.29mg/ml respectively. Of the five UK extracts four showed efficacy in the EHA and/or LMA. The two most efficacious were Carica papaya (papaya) in the LMA and Allium sativum (garlic) in the EHA with ED-50 values of 18.9µM and 0.65mg/ml respectively. The two BPEs most efficacious in vivo for Ethiopia and the UK are to be carried forward to in vivo trials. This study has demonstrated in vitro efficacy of nine plant extracts against cyathostomins. There is evidence in the literature that these plant extracts show efficacy both in vitro and in vivo against GI nematodes in other species. Therefore these results have identified potential alternatives to synthetic anthelmintics for the treatment of cyathostomins that require further investigation. [1] Githiori JB, Athanasiadou S, Thamsborg SM. Use of plants in novel approaches for control of gastrointestinal helminths in livestock with emphasis on small ruminants. Vet Para 2006;139, 308–320.

Anecdotal evidence from animal charities indicates that the number of overweight donkeys in the UK is increasing. Donkeys commonly have daily access to pasture therefore knowledge of grass intake is essential if feeding advice is to be relevant. The effects of herbage mass and length of grazing time on diet composition and dry matter intake (DMI) by mature donkeys were determined.

There were two measurement periods: period 1 during autumn when pasture was sparse (herbage mass 92 + 7g DM/m2) and period 2 during summer when pasture was more abundant (herbage mass 197 + 12g DM/m2). Twenty mature donkeys were selected and split into three grazing groups (8, 12 and 23 h daily grazing access). Barley straw was fed ad libitum and each donkey was given 150mg per day of an n-alkane marker Dotriacontane (C32) for the 12 d of each study period. Herbage mass significantly affected total DMI and diet composition. During summer DMI of donkeys in the 8 and 23h groups was significantly greater than during autumn (P<0.05). The proportion of grass in the diets of all donkeys was also greater in summer compared to autumn (P<0.001). Grazing time did not significantly influence total daily DMI during either season due to donkeys consuming more straw when grass intake was reduced. Restricting donkeys to 12h or less grazing per day in summer significantly (P<0.001) reduced their grass intake compared to that of donkeys with 23h access. When grazing sparse pastures (autumn) time allowed for grazing did not influence grass intake. The results show that time allowed for grazing per se was less important than the herbage mass available to the donkey in terms of grass DMI.

Does the evolutionary history of donkeys lead to behaviours that are misunderstood and contribute to the donkeys’ reputation for being stubborn?

The behaviour of donkeys is an understudied subject. The donkey’s behaviour is commonly misunderstood principally because their behaviour is compared to that of the horse, rather than viewed as a separate species. Mistreatment of donkeys takes place because of the subtle behaviour patterns and stoic nature which are overlooked by handlers and observers who are more familiar with horse behaviour. By looking at the domesticated donkeys’ evolutionary niche and the behaviour of both free living donkeys and domesticated donkeys it possible to explain the different behaviours of donkeys and to lay to rest their reputation for stubbornness and their misrepresentation as small horses with big ears.

This presentation will examine the behaviour of donkeys in the wild, the effects of environment on social structure in Asiatic and African asses, and the effects on behaviour of solitary living and territory guarding both in the wild and domestic situation.

Kenya is home to some 600,000 donkeys that are found virtually in all ecological zones where they provide transport and draught power. In the Lamu archipelago where there is no motorised transport, donkeys are virtually the only available means of transport helping to transport farm produce, building materials and for getting from one place to the next. This study was conducted in April (dry season) and November 2009 (wet season) in four villages in Pate Island to investigate the prevalence and species of trypanosomes infecting donkeys and to identify the fly vectors playing a role in the transmission of trypanosomosis. Blood samples were collected from 288 and 319 donkeys and examined by buffy coat technique (BCT) and Giemsa stained blood smears. Trypanosomes were encountered in 3.1 and 7.5% of the examined donkeys in the dry and wet season respectively and there was no difference in the prevalence between villages during both seasons (p=0.159 and 0.709) but there was a significant difference (p=0.006) between seasons. Three species of trypanosomes detected were, in order of predominance were Trypanosoma congolense Broden (68.7%), Trypanosoma vivax Ziemann (21.8%) and Trypanosoma brucei Plimmer and Bradford (6.2%). Another 6.2% were mixed infections. There difference in mean PCVs between trypanosome infected and non-infected donkeys dry and wet seasons ranging significant to highly significant (p<0.05 and p<0.001) respectively. Trypanosome infection had a significant effect on mean body condition score of the donkeys during both seasons (p<0.05 and p<0.001). Prevalence of trypanosome infection was found to be independent of sex and age. However, mean PCV was significantly associated with age, sex and body condition scores. The entomological surveys revealed the presence of Glossina pallidipes Austen and other biting flies namely Stomoxys spp Linnaeus, Tabanus spp. Linnaeus, and Haematopota spp Linnaeus. Though the use of BCT for detection of trypanosomes in the field is almost universal, it has limited application especially in chronic infections and the field samples are in the process of being analysed using PCR to give a more accurate picture of the prevalence and as it relates to health and productivity of donkeys.

Cyathostomins, the predominant parasitic nematodes of equids, have developed varying degrees of resistance to all three classes of anthelmintic licensed for use in horses. It is essential that the effectiveness of alternative methods of control for these pathogens are quantified, including incorporating climatic data and the commonly advocated practice of removal of faeces from pasture. Here, we obtained monthly faecal worm egg counts (FWEC, n=4,460 individual counts) from 803 donkeys based at The Donkey Sanctuary (Devon, UK). The dataset also included age, sex, field, FWEC history and previous anthelmintic administrations in each individual, as well as the pasture hygiene management method applied in the field where the donkey was grazed. FWEC were analysed alongside local climatic data using a generalised linear mixed model to assess associations between these variables and each observed monthly FWEC. The preferred model was identified using a model selection algorithm based on penalised likelihoods, and associated a 2.1% decrease in FWEC per day with air frost two calendar months ago (p<0.001) and a 38% lower FWEC in groups with twice weekly manual faecal removal compared to those with no faecal removal (p=0.004). Other weather effects, both alone and as interaction terms with the average FWEC of the field were included in the model, alongside individual FWEC history with anthelmintic administration as interaction terms and date as a single term. Our study identifies factors that may be useful as part of on-going predictive modelling based methods of improving targeted selective therapy.

The Donkey Sanctuary is a British charitable organisation based in Sidmouth, Devon, England, which’s mission is to transform the quality of life for donkeys, mules and people worldwide through greater understanding, collaboration and support, and by promoting lasting, mutually life-enhancing relationships. The Donkey Sanctuary was founded in 1969 and registered as a charity in 1973 by Dr Elisabeth Svendsen. The Donkey Sanctuary has a total of seven farms in the UK including a reception farm for new arrivals where the study is based, a laboratory, pathologist and an specialized hospital. The Donkey Sanctuary currently looks after around 2.600 animals (in a total estimated UK census of 10.000 animals).

Animals are admitted into a quarantine Farm where they spend a minimun of 6 weeks to assess their health status including full coprological study. Donkey are relinquished or rescued by the charity and arrive from different origins: directly from a private owner, another organitation or hospital or one of the charity’s holding base located in different parts of the country. This animals wopuld have been previosly admitted into those centres and taken there due to biosecirity reasons or becuase transport could be in detriment of their health at that time. Animals that need urgent veterinary treatment would be sent to the closest equine hospital for treatment until consider fit to be transported.

Management of hundreds of animals and their pasture can be challenging from the parasitological point of view, especially if we tend into consideration that the majority of donkeys unlike horses would be asyntomathic despite having high parasite burdens. It is rare for donkeys to show signs such as diaorrhea, weight loss or a poor body condition that are more commonly found in the horse.