Not published as conference proceedings

Recent clinical and post-mortem studies have documented dental disease as a major but often unrecognized, disorder of equids, including horses and donkeys. A study to investigate the prevalence of oral and dental disorders was performed, in two endangered breeds of donkeys: the Mirandês Donkey and the Zamorano-Leonés Donkey, through a prospective cross-sectional study of 800 donkeys, divided in to 7 age groups (ranging 0–34 years). Cheek teeth disorders were present in 82.8% of study donkeys, ranging from a prevalence of 29.6% in the <2.5 years old group to 100% in the >25 years old group. In addition 74% of donkeys suffered from incisor disorders, ranging from 56.8% in the youngest group to 90.3% in donkeys >25 years.

The study evaluated socio-economic data from individual owners (n=341), owning 86% of the study population (n=688 donkeys), including age, profession, level of education and previous knowledge of dentistry. Results highlighted their advanced age (65.3 years), and the extremely high percentage of owners without previous knowledge of donkey dentistry (97.1%) (331/341). Previous knowledge of dentistry was mentioned only by 2.9% of owners (10/341), mainly by owners with a higher level of education, with 80% (8/10) having 12 years of education or more. However, only two owners had provided previous treatment to their donkeys. It is important to mention that even these two owners had other animals without treatment, meaning that animals were treated when presenting with clinical signs of oral and dental disease and were not treated on a prophylactic basis.

This study highlights the importance of educational programmes focused on the prophylactic importance of donkey dentistry, especially when comparing prevalence of dental disorders in working donkeys and previous knowledge on dentistry.

Together with the millions of horses employed by Allied troops in WW1 were mules. As horse losses mounted many mules were purchased, frequently from far away, arriving by ship to end up in the mud-filled trenches with handlers often ill-equipped to care for them. The introduction of British troops to mules must have been a challenge, as mules were not widely appreciated or used in the UK. A mule is not a horse, and to work successfully with them required a different attitude. A less developed flight response made them hard to drive on, and impossible cavalry mounts; a highly developed fight response made them quick and dangerous adversaries when faced with ill treatment. It was oft stated that there were two types of mule men; those that learnt to work considerately with them and those that ended up in the field hospital!

Understanding of the mule and its unique attributes and character developed and they became firm favourites with many troops who relied upon them to carry their most precious cargo in their calm and enduring way. The relationship between this unique equine and their handlers in WW1 will be examined through the eyes of mule and man.

Although donkeys are considered to be more resistant to trypanosomes, they are often seen causing severe clinical disease, particularly anaemia, lethargy and boor body condition, in immuno-compromised animals due to stress from overwork, poor management practices and low quality diets. Studies made by The Donkey Sanctuary in Kenya showed a high prevalence of both tsetse and none tsetse transmitted trypanosomes. T. congolense and T. brucei sp are the most highly prevalent tsetse transmitted trypanosomes while T. vivax is the second most prevalent, next to T. congolense. Infection prevalence of T. vivax as high as 30% were diagnosed in Kenya and Ethiopia using parasitological techniques. These prevalences could have been higher had they been diagnosed using molecular techniques, as it was shown by the study made in Gambia, in which they found an infection prevalence of 87% using PCR.

Dourine is mostly diagnosed in horses from the highland regions in Ethiopia. Recent serological study made in Ethiopia, however, revealed not only in donkeys but across all agro-ecological zones. However, as the CFT does not differentiate between the infection of Dourine and Surra, it is difficult to know the true epidemiology of these diseases among equids where they both exist. Although Surra is reported in donkeys from different countries, it is not reported in donkeys in Ethiopia. However, Surra is endemic in camels in the arid and semi-arid regions of Ethiopia. The recent migration of camels to the mid-lowland areas during the dry season in search of feed might spread the disease among equids in the area.

A recent study made in Gambia by Glasgow University, funded by The Donkey Sanctuary, showed a fatal neurological syndrome among donkeys and horses caused by trypanosomosis. The aetiological agent of this emerging neurological syndrome has been established based on the presence of trypanosomes in the brain of affected animals. However, given the genetic homology between T. evansi, T. brucei brucei and T. equiperdum, it was not possible to confirm which one of these is causing this devastating condition. To solve this mystery and identify the species of trypanosome involved, study on further molecular characterization of cerebral trypanosomosis is underway in Gambia, a project funded by The Donkey Sanctuary.

The infection of trypanosomes in donkeys raises certain questions that need to be addressed. Given the high infection prevalence in the donkey population and associated diseases:

• Are they really carriers/resistant to trypanosomosis?
• The welfare implication of trypanosomosis in donkeys.
• What would be the role of donkeys in the epidemiology of trypanosomosis?
• The impact of exclusion of donkeys in the control of animal trypanosomosis?

We compared spatial problem solving abilities in the mule (Equus asinus x Equus caballus) with that of its parent species to assess the effects of hybridization on cognition. In a detour task the animals(N=48) were required to make a detour through a gap at one end of a straight barrier in order to reach a visible target. After one, two, three or four repeats (A trials), the gap was moved to the opposite end of the barrier (B trials) and deviations from the straight line and the latency to crossing the barrier were recorded. Mules performed significantly above chance level on their first detour, unlike the other two species. We discuss our results with reference to hybrid vigour and to the flexibility of problem solving strategies with regards to species differences.

In the UK, there are an estimated 10-15, 000 donkeys; most of these are kept as companion animals, while some are used for light riding/driving and as therapy animals.

Donkeys can be a long- lived equid with reported ages commonly into their late 20s and even 30s. As they are not required to perform as athletes, many donkeys enter old age with chronic geriatric problems that need diagnosing and managing.

The donkey is a species with pronounced pain masking behaviours (stoicism), and many serious, painful and even life-threatening illnesses may present only as a generally dull animal with reduced appetite.

There is a general lack of many preventative health measures provided to donkeys including regular dentistry, farriery, anthelmintic treatment, and even vaccination, microchipping and passporting. This means that donkeys not only are more likely to suffer disease themselves but also have the potential to act as sources of disease/infection to other equines.

The net results of all the above is that donkey welfare is frequently compromised and charities such as The Donkey Sanctuary are required to provide assistance or be involved in prosecutions against owners under the Animal Welfare Act.

There are many methods to assess welfare involving animal based and resource based indicators. The Animal Welfare Indicators (AWIN) for donkeys is founded on the principles of good feeding, good housing, good health and appropriate behaviour. Art the Donkey Sanctuary we are using this to monitor the herd health of our donkeys on a regular basis. A larger group of welfare indicators has been developed to assess welfare across the full spectrum of roles that donkeys play globally including in the meat, milk and skin trade. These type of assessments are particularly useful for providing information about groups of donkeys and how to prioritise resources to care for them.

For the individual donkey and owner we have developed a simple Quality of Life framework using eight objective easily identified criteria and one subjective criteria. These are charted on a regular basis with the owner and vet working together to agree on the scoring system.

The criteria that we have found to be of most value are:

• Body condition score - using donkey scales 1 (thin) to 5 (obese)
• Weight in kg - either weigh scales or heart /girth measurements and donkey normogram
• Feed - required to maintain weight or cope with condition
• Medication - for regular use e.g. to stabilise PPID cases, to manage lameness/stiffness
• Dental grade - using The Donkey Sanctuary grading system 1 (good) - 5 (poor)
• Appetite - monitor carefully to ensure no sham eating
• Movement - lameness grade 1 mild - 5 severe. Donkey normal values for radiological parameter of the feet should be used.
• Blood results - using donkey normal values
• Demeanour - general owner assessment of well being - this can be supplemented by a behavioural assessment form that is available to look at normal day to day activity patterns of the donkey.

The system developed uses donkey normal values and knowledge of the variations from the horse to interpret the findings and ensure correct dosing of medications.

When we use this system over a period of time there is a better understanding of the long term needs of the donkey by all parties – vets, owners, and paraprofessionals. Monitoring can result in changes to management that improve QoL and ensure a better life. Conversely monitoring can allow objective measurements to note decline in QoL so that all involved in the care of the donkey can make the decision that euthanasia may be the most humane option. Regular checks reduce the problem that is often seen when owners adapt to a poorer QoL as they fail to notice incremental changes in the animals’ well-being.

There are many ways as vets that we can help donkeys to live good lives; and by knowing their unique characteristics and differences from horses we can ensure that the welfare of donkeys we attend is as good as we can make it.