donkey

The number of donkeys and mules throughout the world is stable, and awareness of their use and concern for welfare, pain recognition and treatment are receiving increasing veterinary interest. Therefore, accurate information about anaesthesia and analgesia in donkeys and mules is important to ever more equine practitioners. Since donkeys are physiologically and pharmacologically different from horses, knowledge on species specific aspects of anaesthesia and analgesia are very important. Mules combine elements from both donkey and horse backgrounds, leading to great diversity in size, temperament and body type. Physiologically, they seem to resemble horses more than donkeys. This review highlights the current knowledge on various anaesthetic and analgesic approaches in donkeys and mules. There is still much information that is not available about donkeys; in many circumstances, the clinician must use available equine information to treat the patient, while monitoring carefully to observe for differences in response to therapy compared to the horse.

The UK public and veterinary profession often think of the equine charity sector as dealing with issues directly related to the UK equine population - overproduction, rehoming, shelter and welfare. However, The Donkey Sanctuary, like many UK-based equine charities, also works in Europe and further afield to try to address a much broader range of issues.

Non-primate hepacivirus (NPHV), equine pegivirus (EPgV) and Theiler's disease associated virus (TDAV) are newly discovered members of two genera in the Flaviviridae family, Hepacivirus and Pegivirus respectively, that include human hepatitis C virus (HCV) and human pegivirus (HPgV). To investigate their epidemiology, persistence and clinical features of infection, large cohorts of horses and other mammalian species were screened for NPHV, EPgV and TDAV viraemia and for past exposure through serological assays for NPHV and EPgV-specific antibodies. NPHV antibodies were detected in 43% of 328 horses screened for antibodies to NS3 and core antibodies, of which three were viraemic by PCR. All five horses that were stablemates of a viraemic horse were seropositive, as was a dog on the same farm. With this single exception, all other species were negative for NPHV antibodies and viraemia (donkeys (n=100), dogs (n=112), cats (n=131), non-human primates (n=164) and humans (n=362). EPgV antibodies to NS3 were detected in 66.5% of horses, including 11 of the 12 horses that had EPgV viraemia. All donkey samples were negative for EPgV antibody and RNA. All horse and donkey samples were negative for TDAV RNA. By comparing viraemia frequencies in horses with and without liver disease, no evidence was obtained that supported an association between active NPHV and EPgV infections with hepatopathy. The study demonstrates that NPHV and EPgV infections are widespread and enzootic in the study horse population and confirms that NPHV and potentially EPgV have higher frequencies of viral clearance than HCV and HPgV infections in humans.

Equine sarcoids are fibroblastic skin tumours affecting equids worldwide. While the pathogenesis is not entirely understood, infection with bovine papillomavirus (BPV) type 1 (and less commonly type 2) has been implicated as a major factor in the disease process. Sarcoids very seldom regress and in fact often recrudesce following therapy. Nothing is known about the immune response of the equine host to BPV. Given that the viral genes are expressed in sarcoids, it is reasonable to assume that vaccination of animals against the expressed viral proteins would lead to the induction of an immune response against the antigens and possible tumour rejection. To this end we vaccinated sarcoid-bearing donkeys in a placebo-controlled trial using chimeric virus-like particles (CVLPs) comprising BPV-1 L1 and E7 proteins. The results show a tendency towards enhanced tumour regression and reduced progression in the vaccinated group compared to control animals. Although promising, further studies are required with larger animal groups to definitely conclude that vaccination with CVLPs is a potential therapy for the induction of sarcoid regression.

An aged female donkey developed a severe, localised, suppurative panniculitis secondary to a skin wound. Bacterial culture of swabs taken from the wound gave a profuse growth of multi-drug-resistant Pseudomonas aeruginosa, a profuse growth of Escherichia coli and a moderate growth of beta-haemolytic Streptococcus species. The lesion did not respond to conventional medical and surgical treatment and continued to progress. Six applications of sterile larvae (maggots) of the common greenbottle, Lucilia sericata, were used to debride the wound successfully.

Donkey milk is a valuable product for babies suffering from multiple-allergies and cosmetic production; therefore, new dairy donkey farms are opening around Europe. Little information is available for farmers on sustainable production of donkey milk, including animal welfare, milk production, and processing. Targeted dissemination of information on appropriate animal management would assist dairy donkey farmers in preventing welfare problems. This research project aims to develop guidelines on good practice principles for sustainable donkey milk production. Different steps were followed to develop the guidelines:

1. Identification of key issues for dairy donkey welfare, analysing the results of previous project and the available scientific literature
2. Systematic review research to select promising solutions for each issue included in the guidelines
3. Stakeholder consultation, in order to increase scientific soundness and to enhance their acceptability throughout the sector
4. Guidelines drafting and revisions by stakeholders
5. Guidelines launch.

The guidelines ‘Dairy donkeys: good practice principles for sustainable donkey milk production’ were launched in December 2017. They include suggestions derived from scientific literature and/or reported by internationally recognised experts. The guidelines provide clear and helpful advice on good animal management practices for anyone interested in donkey milk production. They comprise the following chapters:

• Responsibilities
• Feed and water
• Housing and management
• Donkey health care
• Humane killing
• Appropriate behaviour
• Milking procedures.

The guidelines, translated in different languages (Italian, Spanish, Portuguese, French, Greek and Chinese Mandarin) are freely available online.

The guidelines “Dairy donkeys: good practice principles for sustainable donkey milk production” are freely available online in six languages.

The guidelines provide clear and helpful advice on good animal management practices for anyone interested in donkey milk production.

The guidelines include suggestions derived from scientific literature and/or reported by internationally recognised experts.

Logistic regression analysis was applied to data from a population of donkeys to obtain statistical models estimating the risk of equine sarcoid. Two models were constructed and compared. The group model was derived using the prevalence of animals with sarcoids in groups, classified according to the explanatory variables gender, age at first exposure (considered as age at entry to the population), duration of exposure, and gender by duration of exposure as an interaction. The subject model was derived from individual animal data and consisted of the factor gender with the covariates age at first exposure and duration of exposure. Age at first exposure was represented in the model by linear and quadratic terms, and as an interaction with duration of exposure. Both models provided a good approximation to the observed data. The analyses identified young male donkeys with short duration of exposure as being at highest risk. We concluded that risk assessment using the group model could be used effectively in the clinical management of sarcoids in the population of donkeys. Frequent examination of high risk groups might allow early diagnosis, therapeutic intervention and improved animal welfare.

We investigated perseveration and detour behaviour in 36 equids (Equus caballus, E. asinus, E. caballus x E. asinus) and compared these data to those of a previous study on domestic dogs (Canis familiaris). The animals 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). We recorded initial deviations from the correct solution path and the latency to crossing the barrier. In the A trials, mules crossed the barrier significantly faster than their parental species, the horses and donkeys. In the B trials, following the change of gap location, all species showed a reduction in performance. Both dogs and horses exhibited significant spatial perseveration, going initially to the previous gap location. Donkeys and mules, however, performed at chance level. Our results suggest that hybrid vigour in mules extends to spatial abilities.

Donkeys and mules are frequently kept as companion animals for horses and ponies, with these different equids often being considered a homogenous group. However, the extent to which domestic equids form inter-specific bonds and display similar social behaviour when living in a mixed herd has not previously been studied. Here we compare the social organization of these three (sub)species when housed together, providing the first systematic analysis of how genetic hybridization is expressed in the social behaviour of mules. A group of 16 mules, donkeys and ponies was observed for 70 h and preferred associates, dominance rank and the linearity of the group’s hierarchy was determined. The different equids formed distinct affiliative groups that were ordered in a linear hierarchy with ponies as the most dominant, mules in the middle ranks and donkeys in the lowest ranks. Within each equid subgroup, the strength of the hierarchy also varied. Thus in the present study, the three (sub)species displayed different social organization and levels of dominance and preferred to associate with animals of the same equid type, given the opportunity. These results suggest that different domestic equid (sub) species display variations in social behaviour that are likely to have a strong genetic basis.