DS research

Non-governmental organizations (NGOs) work across the globe to improve the welfare of working equids. Despite decades of veterinary and other interventions, welfare issues persist with equids working in brick kilns. Engagement with all stakeholders is integral to creating abiding improvements to working equid welfare as interventions based purely on reactive measures fail to provide sustainable solutions. Equid owners, particularly those in low to middle-income countries (LMICs), may have issues such as opportunity, capacity, gender or socio-economic status, overriding their ability to care well for their own equids. These “blind spots” are frequently overlooked when organizations develop intervention programs to improve welfare. This study aims to highlight the lives of the poorest members of Indian society, and will focus on working donkeys specifically as they were the only species of working equids present in the kilns visited. We discuss culture, status, religion, and social influences, including insights into the complexities of cultural “blind spots” which complicate efforts by NGOs to improve working donkey welfare when the influence of different cultural and societal pressures are not recognized or acknowledged. Employing a mixed-methods approach, we used the Equid Assessment Research and Scoping (EARS) tool, a questionnaire based equid welfare assessment tool, to assess the welfare of working donkeys in brick kilns in Northern India. In addition, using livelihoods surveys and semi-structured interviews, we established owner demographics, socioeconomic status, ethnicity, religion and their personal accounts of their working lives and relationships to their donkeys. During transcript analysis six themes emerged: caste, ethnicity, inherited knowledge; social status, and impacts of ethnic group and caste; social status and gender; migration and shared suffering; shared suffering, compassion; religious belief, species hierarchy. The lives led by these, marginalized communities of low status are driven by poverty, exposing them to exploitation, lack of community cohesion, and community conflicts through migratory, transient employment. This vulnerability influences the care and welfare of their working donkeys, laying bare the inextricable link between human and animal welfare. Cultural and social perspectives, though sometimes overlooked, are crucial to programs to improve welfare, where community engagement and participation are integral to their success.

Infestations by lice can be a significant clinical and welfare issue in the management of large animals. The limited range of commercial pediculicides available and the development of resistance have led to the need to explore alternative louse management approaches. The results of in vitro and in vivo trials undertaken to control populations of the donkey chewing louse, Bovicola ocellatus (Piaget) (Phthiraptera: Trichodectidae) using the essential oils of tea tree (Melaleuca alternifolia) and lavender (Lavandula angustifolia) are reported here. Results of contact and vapour bioassays showed that 5% (v/v) tea tree and lavender oils resulted in > 80% louse mortality after 2 h of exposure. On farms, separate groups of 10 donkeys sprayed with 5% (v/v) tea tree and lavender oil as part of their usual grooming regime showed significant reductions in louse numbers compared with a control group (0.2% polysorbate 80 in water). These findings indicate that tea tree and lavender essential oils can provide clinically useful levels of control of B. ocellatus when used as part of a grooming routine and suggest that with further development could form the basis of an easy to apply and valuable component of a louse management programme for donkeys

Background

Factors affecting working equid welfare are wide-ranging and reflect cultural, economic and climatic conditions, the type of work equids are used for, and individual differences in the practices of their handlers. In Mexico working equids are widely used for facilitating agricultural activities, however, welfare issues are common.

Objectives

To assess working equids across three communities in Mexico, identify predominant welfare problems and document how these problems vary across locations and associated working roles and species type.

Study design

Cross-sectional survey.

Methods

The study combined the administration of a wide-ranging questionnaire to equid handlers/owners and a welfare assessment of their animal. 120 equid owners were asked about their equid management practices, the working conditions and health status of their animal. The welfare of their equids (56 donkeys, 7 mules, 57 horses) was assessed by evaluating body condition, signs of illness or injury, and behavioural indicators.

Results

Welfare varied by species, working role, sex and location. The poorest welfare was seen in one of the two arid regions (the third location having a tropical climate). Donkeys had poorer welfare than horses, and equids used for packing had poorer welfare than those used for riding and agroforestry. Overall poor body condition and wounds were the most common problems seen.

Main limitations

Work type, species type and location strongly co-varied, thus the impact of each factor could not be assessed in isolation. The sample size was relatively small.

Conclusions

Results showed significant regional variations in welfare, suggesting that environmental and/or cultural variations are producing a major effect on welfare.

Published online ahead of print.

The microhardness of the enamel, primary dentine and regular secondary dentine of seven donkey and six horse incisors was determined with a Knoop indenter at the subocclusal and mid-tooth level. The mean microhardnesses of the donkey incisor enamel, primary dentine and secondary dentine were 264·6 63·00 and 53·6 Knoop Hardness Number, respectively. There was no significant difference between the microhardness of the enamel and primary dentine on the incisors of the donkeys and horses, but the microhardness of the regular secondary dentine of the donkeys' incisors at the mid-tooth level was slightly but significantly less than that of the horses. There was also a difference in the microhardness of the secondary dentine between the subocclusal and mid-tooth levels in both donkey and horse incisors.

Because most donkeys live well beyond 30 years of age (Crane 1997), it has been proposed that their teeth may be harder than the teeth of horses, wear more slowly, and thus remain functional for longer (Misk and Seilem 1999). There have been studies of dental microhardness in human beings (Craig and Peyton 1958, Collys and others 1992), sheep (Suckling 1979), cattle (Attin and others 1997) and horses (Muylle and others 1999b). In horses, there are differences between breeds in the rate of dental wear caused by attrition (Muylle and others 1997, 1998) and in the microhardness of enamel and secondary dentine (Muylle and others 1999b), which could account for these differences. It is proposed that there may be a similar difference between the microhardness of the teeth of donkeys and horses that may contribute to the less rapid attrition of donkey teeth.

The aim of this study was to compare the microhardness of the enamel and primary and secondary dentine of the incisor teeth of donkeys and horses, to determine whether there was a significant difference between them.

Soil Compaction results from compressive forces applied to compressible soil by machinery wheels, combined with tillage operations. Draft animal‐pulled equipment may also cause soil compaction, but a huge gap exists on experimental data to adequately assess their impacts and, actually, animal traction is an option seen with increasing potential to contribute to sustainable agriculture, especially in mountain areas. This study was conducted to assess the impacts on soil compaction of tillage operations with motor tractor and draft animals. In a farm plot (Vale de Frades, NE Portugal) treatments were applied in sub‐plots (30 m x 3 m), consisting in a two way tillage with tractor (T), a pair of cows (C) and a pair of donkeys (D). Undisturbed soil samples (120) were taken before and after operations for bulk density (BD) and saturated hydraulic conductivity (Ks). The relative changes in BD observed after tillage in the 0-0.05 m soil depth increased after operations in all treatments. The increase was higher in the tractor sub-plot (15%) than in those where animal traction was used (8%). Before operation Ks class was rapid and fast in all samples, and after operation this value was reduced to 33% in T, whereas it reached 83% in C. Electrical Resistivity Tomography (ERT) was useful as a tool to identify the alterations caused by tillage operations on soil physical status. These preliminary results confirm the potential of animal traction as an option for mountain agri‐environments, yet it requires much wider research to soundly ground its assets.

Over 38% of the world equine population (114 million) is made up of donkeys and more than 97% are found in developing countries and are specifically kept for work. Despite their significant contribution to the national economy, the attention given to study the infectious diseases of working donkeys is minimal. To address this The Donkey Sanctuary has been conducting studies in collaboration with Addis Ababa and Nairobi Universities, Central Veterinary Research Laboratory (CVRL) in Dubai and the Trypanosomosis Research Centre (TRC) in Kenya. These studies have shown a high prevalence of some important infectious diseases.

Helminthosis

Helminth infection profiles of working donkeys living in semi-arid or tropical conditions are often very different from those of equids in temperate climates. They are often diagnosed with a high worm burden or faecal egg count irrespective of their age. The high level of age-independent infection may show that donkeys either do not develop protective immunity or that they might have become immuno-compromised, consequent upon the stress of their work intensity and/or undernourishment and general poor husbandry.

Trypanosomosis

Although there is a general belief that donkeys are more resistant, trypanosomosis has been shown to cause severe clinical disease in working donkeys. Epidemiological studies in Ethiopia and Kenya have shown that the prevalence of trypanosomosis was as high as 65%, often with mixed infections of two or more species. In both countries T. congolense was the predominant species followed by T. brucei and T. vivax; often associated with anaemia and poor body condition. Trypanosomosis is claimed by local farmers as the major health constraint of donkeys in both countries. Recent serological studies by The Donkey Sanctuary in collaboration with the CVRL showed a sero-prevalence of 1.1% (n=662) T. equiperdum in Ethiopia.

Piroplasmosis

Equine piroplasmosis is one of the most significant tick-borne diseases of donkeys in Ethiopia and Kenya. Recent studies in Ethiopia in collaboration with CVRL showed sero-prevalence of 53.3% to 58% T. equi and 13.2%-13.3% B. caballi (n=15-395) Most of the cases were associated with anaemia. Similar studies in Kenya reported only T. equi with a sero-prevalence of 81.2% (n=314).

Viral and bacterial diseases

A recent study in Ethiopia in collaboration with CVRL showed a sero-prevalence of 8.5% (n=165) AHS, 84.6% (n=104) EHV-4, 20.2% (n=104) EHV-1, 0.5% (n=662) glanders and 0.2% (n=657) EIA. Similar study made in Kenya also showed a sero-prevalence of 35.2% (n=398) AHS. Donkeys showing typical clinical signs of AHS were noted in Kenya and Ethiopia. Although no epidemiological studies are available, cases of tetanus, strangles, rabies, anthrax and dermatophilosis are common occurrences in donkeys. These studies highlight how important infectious diseases in donkeys are and the need to consider them in overall epidemiological studies and for sound control and prevention strategies.

Roundworms and flatworms that affect donkeys can cause disease. All common helminth parasites that affect horses also infect donkeys, so animals that co-graze can act as a source of infection for either species. Of the gastrointestinal nematodes, those belonging to the cyathostomin (small strongyle) group are the most problematic in UK donkeys. Most grazing animals are exposed to these parasites and some animals will be infected all of their lives. Control is threatened by anthelmintic resistance: resistance to all 3 available anthelmintic classes has now been recorded in UK donkeys. The lungworm, Dictyocaulus arnfieldi, is also problematical, particularly when donkeys co-graze with horses. Mature horses are not permissive hosts to the full life cycle of this parasite, but develop clinical signs on infection. In contrast, donkeys are permissive hosts without displaying overt clinical signs and act as a source of infection to co-grazing horses. Donkeys are also susceptible to the fluke, Fasciola hepatica. This flatworm can be transmitted, via snails and the environment, from ruminants. As with cyathostomins, anthelmintic resistance is increasing in fluke populations in the UK. A number of the anthelmintic products available for horses do not have a licence for use in donkeys, and this complicates the design of parasite control programmes. As no new equine anthelmintic classes appear to be near market, it is important that the efficacy of currently effective drugs is maintained. It is important that strategies are used that attempt to preserve anthelmintic efficacy. These strategies should be based on the concept that the proportion of worms in a population not exposed to anthelmintic at each treatment act as a source of ‘refugia’. The latter is an important factor in the rate at which resistance develops. Thus, it is imperative that parasite control programmes take into account the need to balance therapy to control helminth-associated disease with the requirement to preserve anthelmintic effectiveness.

Normal dental anatomy and the range of dental disorders found in donkeys are largely similar to those described in horses. Recent studies have shown dental disease to have a high prevalence in donkeys. Some dental disorders, such as diastemata, displaced teeth and wave mouth can have serious clinical consequences by causing oral pain and weight loss and even predispose to colic. Many of these signs can be prevented by regular dental treatment that can slow down or even prevent the progression of these disorders.

Clinical evaluation and preventative care in donkeys should follow similar guidelines as for horses. There are species-specific differences due to the desert-adapted physiology of the donkey. Donkeys are mainly used as pack animals, companions and for production of meat or milk - they may be kept well into old age. Diseases often present late or may go unrecognized leading to poor welfare and quality of life. Basic knowledge of nutrition, blood values, pharmacology and common disease recognition will help veterinarians improve the health and welfare of donkeys.

Published online ahead of print.

Clinical dental examinations of 203 unsedated working donkeys in tropical and temperate climatic areas in Mexico revealed a high prevalence (62%) of dental disease with sharp enamel points present in 98% of the animals. More significant dental disorders (diastemata, 4%; overgrown teeth, 18%; worn teeth, 16%; missing teeth, 0.5%; displaced teeth, 1.5%; fractured teeth, 2%) with welfare implications that required immediate treatment were also present in 18% of donkeys. The high prevalence of buccal ulcers (14.3%) and calluses (13.3%) present in this population was believed to be due to the high prevalence of sharp enamel points in conjunction with the use of tight nose bands and head collars. Dental disease was significantly associated with age groups, but not with body condition score or to the climatic area where the donkeys lived. As part of more general examinations, 81% of donkeys that had faecal egg counts performed, had parasite burdens which mainly showed a moderate level of infection. This study concluded that dental disease is a welfare concern in working donkeys in Mexico.