donkey

Background

The involvement of Besnoitia bennetti in skin pathologies was investigated in a series of 20 donkeys from the Donkey Sanctuary in England, in the 2013–2019 period.

Methods

The initial histopathological finding of Besnoitia cysts in skin lumps that were presumed to be sarcoids in 2013 triggered our cognisance of this parasite and resulted in identification of a total of 20 cases. Histopathological examination of surgical biopsy samples collected from 8 live donkeys and tissue specimens from 12 deceased donkeys at post-mortem examination revealed the presence of Besnoitia cysts in all 20 donkeys. The indirect fluorescent antibody test (IFAT) and immunoblotting analysis showed the presence of anti-Besnoitia antibodies in archived serum samples from 4 deceased donkeys. Additionally, infection was evidenced in one live donkey based on IFAT and immunoblot analysis of tissue fluid of a dermal mass containing Besnoitia cysts, and real-time (RT)-PCR analysis and microsatellite genotyping of DNA isolated from the tissue of the same dermal mass confirmed the infection specifically as B. bennetti.

Results

Both serological and microsatellite analyses confirmed the aetiology to be B. bennetti. Our findings suggested that in cases of skin masses such as sarcoids, the suspicion of B. bennetti infection should be borne in mind even when clinical and histopathology examination results are negative in order to avoid misdiagnosis.

Conclusions

This case series documents, to our knowledge, the first report of B. bennetti infection in donkeys in the UK, indicating that donkey besnoitiosis has become noteworthy in the UK. Further investigations of the occurrence, epidemiological characteristics, and clinical manifestations of B. bennetti infection in donkeys and other equids are warranted.

The efficacy of an oral formulation of praziquantel (Equitape, Horse paste, Fort Dodge) in the reduction of cestode egg counts and serum antibody level against Anoplocephala perfoliata was assessed in 44 donkeys under field conditions. The donkeys were confirmed both by faecal examination and serum antibody assessed by an enzymelinked immunosorbent assay to have natural infection with tapeworms. The donkeys were randomly allocated into treatment (n022) and control (n022) groups. The treatment group was treated with both praziquantel and ivermectin (Ivomec, Merial) at a dose rate of 1 mg/kg and 200 μg/kg, respectively while the control group was treated only with ivermectin. Faecal samples were collected before treatment (day-0) and 2, 6, 8, 12, and 16 weeks post-treatment while blood samples were collected before treatment and 8 and 16 weeks after treatment and analysed. The results of the study demonstrated that praziquantel paste was highly effective in reducing cestode eggs in donkeys and had an efficacy of more than 99 % until week 16 (day112). No cestode egg reappearance by 16 weeks post-treatment in any animal in the treatment group was observed while donkeys in the control group continued shedding cestode eggs. The immunological assay also showed a significant reduction in serum antibody level against A. perfoliata in treated donkeys compared to the control group (p00.0001). This marked decrease in serum antibody level indicates reduced risk of cestode-associated colic and other gastrointestinal disorders and clinical diseases. No adverse reactions or clinical effects were encountered in any animal within either group throughout the trial period.

Intestinal motility disorders are an important problem in horses and donkeys and this study was carried out in order to evaluate the enteric neurons in animals with and without intestinal disease. Surplus intestinal tissue samples were collected from 28 horses undergoing exploratory laparotomy for colic. In addition, surplus intestinal samples from 17 control horses were collected immediately following humane destruction for clinical conditions not relating to the intestinal tract. Similar samples were also collected during routine post-mortem examinations from 12 aged donkeys; six animals were humanely destroyed for conditions related to the intestinal tract, while the remaining six were humanely destroyed for other reasons including dental and orthopaedic diseases. Tissue samples were fixed in formalin and immunohistochemical labelling was performed targeting the enteric neurons using a polyclonal antibody specific for the neuronal marker PGP 9.5. The distribution and density of neuronal networks were assessed qualitatively and semiquantitatively. There was strong PGP 9.5 expression in both the horse and donkey samples and labelling was detected throughout the tissue sections. In both species, PGP 9.5-immunoreactive nerve fibres were detected in all layers of the intestinal tract, both in large and small intestinal samples. Networks of enteric neurons were present in the donkey with a similar distribution to that seen in the horse. There was no demonstrable difference in enteric neuronal density and distribution in the groups of animals with intestinal disease compared with those without, apart from two (out of 28) horses with intestinal disease that showed a marked reduction in PGP 9.5 immunoreactivity. Apart from these two animals, this total cohort analysis differs from some previously observed findings in horses with intestinal disease and may therefore reflect the different pathophysiological processes occurring in varying intestinal conditions resulting in colic both in the donkey and the horse.

Using equids for their assumed therapeutic impact on humans is a growing area of ​​knowledge in human health sciences. The impact of Equid Assisted Activities (EAA) is often measured by psychometric test score changes for the human. Thus, evidence for the practice tends to be assessed through an anthropocentric lens. The research described in this article consisted of exploring a mixture of quantitative and qualitative methodologies for measuring EAA through the perspective of autistic children and their donkey partners. The Quality of Engagement Tool (QET) is introduced as an instrument to measure ongoing engagement between participants during sessions. Narrative Analysis and Narrative Ethology captured tangential and sequential stories of interactions that revealed the individuality of each child or donkey participant's experience. The findings identified that one participant was able to affect their partner's engagement behavior irrespective of species, and that both donkeys and children modified their behaviors when interacting with a member of the opposite species. The results suggest that, in principle, EAA has the potential to bring about behavioural changes to the other species. Therefore, in order to ensure validity, both the human and equid's ongoing responses must be measured equally in future research.

Published online ahead of print.

Reasons for study

Chewing lice are widespread and clinically compromising parasites of livestock and equines. Their management is complicated by growing levels of resistance to commonly applied insecticides. Hence, the development of novel approaches to their control is of major clinical interest.

Objectives

To assess the effects of incorporating the essential oils of tea tree and lavender into a grooming programme for populations of donkeys with natural infestations of Bovicola ocellatus in the UK and Ireland when louse populations were at their winter seasonal peak.

Study design:

In vivo field trial.

Methods

Suspensions of 5% (v/v) tea tree or lavender oil or an excipient only control, were groomed into the coats of winter-housed donkeys (n = 198) on 2 occasions, 2 weeks apart. Louse counts were conducted before each application and 2 weeks later.

Results

After 2 applications, the groups groomed with lavender or tea tree oil suspensions had a significant reduction in louse intensity, with a mean decline in louse abundance of 78% (95% CI 76-80%). Louse numbers in the groups groomed with excipient only either did not change or increased significantly. Donkey hair length had no effect on the decline in louse numbers.

Conclusions

These results demonstrate that the inclusion of essential oil suspensions during grooming can be used to manage louse populations successfully. This article is protected by copyright. All rights reserved.

A cross-sectional coprological survey in the regions of Ada, Akaki, Bereh and Boset, and a retrospective postmortem investigation were conducted to study the epidemiology of Parascaris equorum in donkeys and horses in Ethiopia. Faecal samples from 803 working donkeys and 402 horses were collected, and the numbers of worms recovered from 112 donkeys examined postmortem between 1995 and 2004 were analysed. There was a high prevalence of infection and faecal egg output of Parascaris equorum in both donkeys and horses, and the severity of the infection in donkeys was increased irrespective of their age. The prevalence of the infection in the donkeys was 51·1 per cent and in the horses 16·2 per cent, and the prevalence in the donkeys examined postmortem was 55 per cent. There was no significant difference between different age groups of donkeys in either the prevalence or the intensity of the infection. The prevalence of the infection was significantly higher in the Ada and Akaki regions than in the Bereh and Boset regions.

Parascaris equorum is an important parasite of young horses, particularly sucklings and weanlings (Russell 1948, Soulsby 1982, Austin and others 1990, Southwood and others 1998). The parasite has a worldwide distribution, and is usually present wherever horses are raised (Clayton 1986, Southwood and others 1998). It can reduce the growth rate of foals and cause occasional deaths due to intestinal obstruction or rupture (Dipietro and others 1983, Clayton 1986, Ryu and others 2004).

Parascaris equorum has also been reported in donkeys from various regions of the world (Tolliver and others 1985, Vercruysse and others 1986, Pandey and Eysker 1990, Ricci and Sabatini 1992, Burgu and others 1995, Daoud and Al-Alousi 1995, Feseha 1998, Lewa and others 1998, Getachew 1999, Kotwal and others 2000, Matthee and others 2002). However, most of these reports concern only small numbers of animals, and the information is rather fragmentary. There have been no specific studies of the epidemiology, pathogenicity and immunology of parascarid infections in horses and donkeys under the tropical weather conditions of Ethiopia. The aim of the present study was to investigate the epidemiology of this parasite in working donkeys and horses in Ethiopia by means of a cross-sectional coprological survey and retrospective postmortem examination findings.

Background

Domesticated grazing animals including horses and donkeys are frequently housed using deep litter bedding systems, where it is commonly presumed that there is no risk of infection from the nematodes that are associated with grazing at pasture. We use two different approaches to test whether equids could become infected with cyathostomines from the ingestion of deep litter straw bedding.

Methods

Two herbage plot studies were performed in horticultural incubators set up to simulate three straw bedding scenarios and one grass turf positive control. Faeces were placed on 16 plots, and larval recoveries performed on samples of straw/grass substrate over 2- to 3-week periods. Within each incubator, a thermostat was set to maintain an environmental temperature of approximately 10 °C to 20 °C. To provide further validation, 24 samples of straw bedding were collected over an 8-week period from six barns in which a large number of donkeys were housed in a deep litter straw bedding system. These samples were collected from the superficial bedding at 16 sites along a “W” route through each barn.

Results

No infective larvae were recovered from any of the plots containing dry straw. However, infective cyathostomine larvae were first detected on day 8 from plots containing moist straw. In the straw bedding study, cyathostomine larvae were detected in 18 of the 24 samples. Additionally, in the two barns which were sampled serially, the level of larval infectivity generally increased from week to week, except when the straw bedding was removed and replaced.

Conclusions

We have demonstrated that equine cyathostomines can develop to infective larvae on moist straw bedding. It is therefore possible for a horse or donkey bedded in deep litter straw to become infected by ingesting the contaminated straw. This has implications for parasite control in stabled equids and potentially in housed ruminants, and further investigation is required in order to establish the relative infective pressure from pasture versus straw bedding.

A 12/13 kDa antigen, tapeworm ELISA test, developed for use in horses, was used to detect parasite-specific serum antibody, IgG(T), in the serum of donkeys. In a pilot study the 12/13 kDa antigen was tested and proved to detect the antibody, IgG(T), in donkey sera. Blood samples from 797 donkeys, naturally exposed to cestode infection, from four geographical localities were collected and sera were prepared and analysed. There was substantial serological evidence that donkeys were potentially infected with A. perfoliata. A range of ELISA OD values were obtained from the serological assay. Over 26% and 7.5% of the donkeys were moderately and highly infected, respectively, showing at least a 34% sero-prevalence. The rest, 66.1%, were either with low infection intensity or negative for A. perfoliata infection. The risk of infections, both in sero-prevalence and intensity, as determined by ELISA optical density (OD), were highest in the highland areas of Ethiopia where pastures are low-lying and wet, and permanent pasture management is regularly practised. Sex, age and body condition of the donkeys had no significant effect either on prevalence of the infection or on the serum antibody level. These results indicate a risk of intestinal disorders, particularly, colic, associated with A. perfoliata infection in donkeys.

Background

Colic (abdominal pain) is a clinical condition of serious concern affecting the welfare and survival of donkeys at The Donkey Sanctuary in the UK. One of the most commonly reported causes is due to impacted ingesta in the large intestine ("impaction colic"). However little is known about the incidence of, or risk factors for, this condition. Here we describe the epidemiology of colic in donkeys, specifically impaction colic. We focus on temporal aspects of the disease and we identify environmental and management related risk factors for impaction colic in UK donkeys.

Results

There were 807 colic episodes in the population of 4596 donkeys between January 1st 2000 and March 31st 2005. The majority (54.8%) of episodes were due to a suspected or confirmed diagnosis of impaction of the gastrointestinal tract. The mortality risk for all colics (51.1%) was higher than reported in other equids. The incidence rate of all colics (5.9 episodes per 100 donkeys per year) and of impaction colic (3.2 episodes) was similar to that in horses. A retrospective matched case-control study of all impaction colics from January 2003 (193) indicated that older donkeys, those fed extra rations and those that previously suffered colic were at increased risk of impaction. Lighter body weight, musculo-skeletal problems, farm and dental disease were also significantly associated with a diagnosis of impaction colic.

Conclusion

To our knowledge this is the first study to estimate the incidence rate of colic in a large population of donkeys in the UK. In contrast to other equids, impaction was the most commonly reported cause of colic. We identified several risk factors for impaction colic. Increasing age, extra rations and previous colic are known risk factors for colic in other equids. Results support the hypothesis that dental disease is associated with impaction colic. Musculo-skeletal problems may be associated with colic for various reasons including change in amount of exercise or time at pasture. Other associated factors (weight and farm) are the subject of further research. Identification of risk factors for impaction colic may highlight high risk donkeys and may allow intervention strategies to be introduced to reduce the incidence of the disease.

A cross-sectional coprological survey in the tropical regions of Ada, Akaki, Bereh and Boset, and a retrospective post-mortem investigation were conducted to study the epidemiology of fasciolosis in working donkeys in Ethiopia. Faecal samples from 803 donkeys were collected, and the number of liver flukes recovered from 112 donkeys at post-mortem between 1995 and 2004 were analysed. There was a high prevalence of fasciolosis irrespective of the age of the donkeys. The overall prevalence of the infection was 44.4% in coprologically examined donkeys, and the prevalence in the donkeys examined post-mortem was 41.9%. The infection prevalence was significantly higher in Bereh and Ada regions than in Akaki and Boset regions. Bereh with 72.6% and Boset with 21.5% showed a significantly higher and lower infection prevalence, respectively, than the rest of the regions (P<0.001). There was no significant difference between different age groups of donkeys in the infection prevalence (P>0.05) but infection intensity was significantly higher in donkeys 8 years old and above (P<0.0001). Both Fasciola hepatica and Fasciola gigantica were identified.