United Kingdom

Many studies that regard the effectiveness of animal assisted interventions are in fact only interested in the child, assuming that the animals in the research are a homogenous group whose characters and emotional states don’t play a part. Both nonverbal autistic children and donkeys communicate with gesture and often with limited vocalisations.

Both come from a social species and are sentient. Their individual emotional states must affect the other.

This study places both the nonverbal autistic children and the donkeys that facilitate their intervention as equal participants, thus recording both species responses using a qualitative behaviour analyses tool and a multispecies ethnographic approach.

Anthelmintic resistance is a growing problem in both the developed and developing world; of most concern is the level of resistance detected against the potent macrocylic lactone (ML) anthelmintics. To identify and target a common mechanism of resistance to anthelmintics would allow potential modification of existing drugs, and may even enable the prediction and prevention of the development of resistance to novel drugs. There is a growing body of evidence that P-glycoproteins (P-gps) are involved in resistance to the MLs in many parasitic nematodes of humans and veterinary species (Ardelli et al, 2011). P-gps belong to class two of the ATP binding cassette (ABC) transporter protein superfamily; they are responsible for the active removal of xenobiotic compounds from cells. The cyathostomins are gastrointestinal nematodes of equids that cause significant pathology. Recently resistance to MLs has been described in cyathostomins (Molento et al, 2008), its mechanisms have not yet been elucidated.

Anthelmintic resistance is a major veterinary and public health issue globally, of most concern is the level of resistance to the macrocyclic lactones. Recent studies have identified a role in resistance for the ATP binding cassette (ABC) drug transporters, P-glycoproteins (P-gps). This study demonstrates the effect of the P-gp inhibitor ketoconazole on the efficacy of ivermectin (IVM) against equid cyathostomin larvae using the larval migration inhibition test (LMIT). Third stage cyathostomin larvae (L3) were cultured from two populations; 1) with recent history of IVM resistance in vivo and 2) naive to anthelmintic exposure. The sensitivity to IVM in each group (n=8) was characterised using the LMIT. The IVM LMIT was repeated for each sample with and without the addition of 10µM ketoconazole. Probit analysis was performed on grouped data from each population to give LC-50 values. The LC-50 value for IVM in Populations 1 and 2 was 4.9 and 2.4µg/ml respectively indicating that Population 1 has a resistant phenotype in comparison to Population 2. Addition of 10µM ketoconazole to IVM in Population 1 caused a drop in LC-50 value from 5.8 to 1.6µg/ml. In Population 2 the effect of the addition of ketoconazole was negligible (1.1 to 0.9µg/ml). This study demonstrates that the P-gp inhibitor ketoconazole causes reversion to a sensitive phenotype in IVM-resistant cyathostomins, inferring that P-gps play a role in their resistance to IVM. This work will be corroborated by investigation into P-gp genes and their expression in cyathostomins.

Any donkey of 20 years of age or older is considered to be geriatric. While companion animals will form the mainstay of geriatric donkey patients, it is not uncommon to experience aged working donkeys overseas and the following comments may be equally applicable.

Conditions of geriatric donkeys are frequently overlooked not receive regular, thorough inspection. Veterinarians may be called upon in an emergency situation, or, ideally, annual veterinary checks may be in place as part of routine vaccination protocols. It is important that any associated paraprofessionals are also aware of care of the geriatric donkey, as farriers and dental technicians can play a vital role in alerting owners to any potential health problems.

Stoic in nature, the donkey’s inherent behavioural response is to avoid displaying pain, thus the true extent of a pathological condition may be easily missed; it is vital that a thorough clinical examination of the whole donkey takes place at every veterinary visit. Beneath the thick coat may lie an underweight or obese animal, or advanced skin disease. Respiratory and musculoskeletal conditions of the non-athletic donkey may not be apparent at rest until an advanced stage has been reached. Research from The Donkey Sanctuary has identified a high proportion of advanced dental disease and poor to no routine dental care in relinquished geriatric donkeys (unpublished data). Heavy endo- and ectoparasite burdens have been seen in geriatric donkeys at The Donkey Sanctuary.

Chronic laminitis is highly prevalent but frequently overlooked by owners. Classic weight shifting is less reported in donkeys, with subtle changes in gait the more frequent indicator; depressed demeanour, muscle wastage over the shoulders and a reluctance to walk, alongside external hoof changes, should all trigger a check for laminitis. Hoof radiography is strongly advised to aid diagnosis and assist with remedial farriery.

Testing for pituitary pars intermedia dysfunction (PPID) is advised in cases of chronic laminitis, particularly where changes in demeanour, muscle wastage, recurrent infections and high faecal worm egg counts are seen. The classic hirsutism and hyperhidrosis seen in horses is not commonly identified in the donkey. Presently, measurement of basal adrenocorticotropic hormone (ACTH) is advised as a diagnostic test. Use of the thyrotropin-releasing hormone (TRH) stimulation test may be advisable in equivocal cases, although donkey-specific reference ranges have not been validated. If PPID is diagnosed, therapeutic management with pergolide mesylate at standard equine doses is valid, although owners should be cautioned as to the potential for inappetence and secondary hyperlipaemia.

Osteoarthritis of the axial and appendicular skeleton is very common. Owners may notice little more than a reduction in ambulation of the donkey and deterioration in temperament on handling. An onset of reluctance to raise the limb for foot care may indicate pain of the limb joints. Farriers should be advised to keep the limb as low as possible during foot trimming sessions. A donkey that rarely lies down or rolls or has sores over the carpi or hocks is also a cause for concern. Management of the arthritic patient should involve careful weight control, access to flat pastures where possible, routine farriery, consideration of appropriate bedding material, and adequate analgesia. Appropriate analgesics include phenylbutazone 2.2 mg/kg bwt orally twice a day or carprofen 0.7–1.3 mg/kg bwt orally once a day. Firocoxib has been used, but to this author’s knowledge there are no published data relating to its use in donkeys. Paracetamol 20 mg/kg bwt orally twice a day has been used as short-term adjunctive analgesia in acute-on-chronic presentations of both osteoarthritis and laminitis. While gastric ulceration has been seen at postmortem examination, there have been no studies linking its occurrence with long-term NSAID administration in donkeys.

Weight loss is a common presentation of the geriatric donkey. Diagnostic work-up should follow the same principles as for other equines. Liver disease appears to be relatively prevalent in the geriatric weight loss case, with liver fibrosis not infrequently seen at post-mortem examination. A thorough dental examination is paramount in weight loss cases; significant and painful dental disease is often identified.

Conversely, obese geriatric companion donkeys are also frequently seen and pose a particular hyperlipaemia risk. The diet of the geriatric donkey should be adjusted to account for desired weight, seasonality, underlying health concerns and dental disease. Short-chop forage products may replace straw for donkeys with poor dental function. Poor dental function and failure to provide access to warm drinking water in colder months have been significantly associated with an increased incidence of impaction colic in geriatric donkeys [1]. Balancer products should be fed to reduce vitamin and mineral deficiencies.

Ocular lesions are often identified during routine clinical examinations of the geriatric donkey. Advanced cases of uveitis, non-ulcerative keratitis and glaucoma may be present despite little indication of pain, while cataract formation is seen regularly. Ocular conditions should be treated and monitored as for other equines, with particular emphasis to owners on the subtle clinical signs of pain in the donkey.

Interstitial pulmonary fibrosis appears relatively prevalent amongst geriatric donkeys presenting with respiratory disease. Disease is rarely recognised until advanced, and/or secondary bacterial pneumonia has increased the severity of clinical signs. The disease is invariably fatal, although over wideranging time periods. Ultrasonographic imaging and thoracic radiography can aid the diagnosis where the clinical signs raise suspicion of disease. Equine herpesvirus-5 has been isolated from bronchoalveolar lavage samples taken from donkeys with confirmed pulmonary fibrosis, and asinine herpes viruses have been detected in donkeys with interstitial pneumonia; however, the precise role of herpesviruses in donkey pulmonary fibrosis has not been definitively established [2,3].

Tracheal collapse has been identified in a high number of geriatric donkeys at post-mortem examination, such that age-related degeneration of the tracheal rings is thought to be common. Clinical signs are rarely seen unless advanced stenosis is present; the presence of concurrent respiratory disease may severely exacerbate clinical signs [4].

Quality of life assessments can play a vital role in monitoring geriatric donkeys with chronic conditions. Informal discussions will likely form a mainstay of regular consultations, while more formal recording sheets can assist owners to identify any decline in their donkey’s condition or highlight issues in the case of working donkeys.

Discussing and defining ‘end-of-life’ points is a critical part of this process. Awareness of pain scoring systems, including facial pain recognition scales, can provide useful information relating to the efficacy of analgesia and true severity of any chronic disease processes. Euthanasia of the donkey follows the same basic principles as for other equines. In the UK, Somulose® is the most commonly employed agent. It is essential to have a calm and experienced handler to assist with euthanasia. Due to the small size of the average donkey found in the UK, i.v. agents are frequently given off the needle, but use of an i.v. catheter is down to personal preference. Certain anatomical differences, namely, thicker skin and a prominent cutaneous colli muscle, can make jugular venepuncture more difficult than in horses. It is vital that any companion is allowed access to the deceased donkey until they lose interest in the body; this can take from minutes to hours. Owners should be advised to monitor closely the companion, as bereavement stress has been known to elicit hyperlipaemia. Further information can be found in The Clinical Companion of the Donkey [5].

References

1. R. Cox, C. J. Proudman, A. F. Trawford, F. A. Burden. (2007) Epidemiology of impaction colic in donkeys in the UK. BMC Veterinary Research 3, 1-11.
2. S. B. Kleiboeker, S. K. Schommer, P. J. Johnson, B. Ehlers, S. E. Turnquist, M. Boucher, J. M. Kreeger. (2002) Association of two newly recognized herpesviruses with interstitial pneumonia in donkeys (Equus asinus). Journal of Veterinary Diagnostic Investigation 14, 273-280.
3. A. K. Thiemann. (2012) Respiratory disease in the donkey. Equine Veterinary Journal 24, 469-478.
4. R. J. Powell, N. Du Toit, F. A. Burden, P. M. Dixon. (2010) Morphological study of tracheal shape in donkeys with and without tracheal obstruction. Equine Veterinary Journal 42, 136-141.
5. L. Evans, M. Crane. (2018) Euthanasia and the post-mortem examination. In: Clinical Companion of the Donkey, 1st edition, Troubador Publishing Ltd, Leicestershire. p 196.

Introduction

Herbal medicines have been used in human and animal medicine for centuries to treat parasitic diseases; few examples have been investigated for genuine anti-parasitic activity. In developing countries access to effective anthelmintic treatment for livestock is often limited by cost, availability and variable quality. Reports of resistance to benzimadazoles in ruminants in Ethiopia serve as a warning that anthelmintic resistance may also be an emerging problem [1,2]. In light of these issues there is increasing interest in plant remedies as alternatives to synthetic anthelmintics. This study used a participatory rural appraisal (PRA) to identify plants with potential anthelmintic activity in the Oromia region of Ethiopia; five plant extracts were shortlisted and tested for efficacy against cyathostomins using in vitro assays. Current attitudes to ethnoveterinary medicine were discussed.

Methods

Focus group discussions with 29 groups of donkey owners from the Oromia region of Ethiopia explored the use of plants to treat GI parasites in livestock. Current attitudes to herbal medicines were discussed and recorded using thematic analysis. Plants of interest were collected and identified at the National Herbarium, Addis Ababa, Ethiopia. Plants were shortlisted for in vitro tests based on four criteria; ranking in the PRA, supportive literature, no evidence of toxicity and availability. Hydro-alcoholic extraction of dried plant material from shortlisted species was performed. The efficacy of extracts was evaluated in the egg hatch assay (EHA) using cyathostomin eggs recovered from the faeces of donkeys at the Donkey Sanctuary, UK. Dose response curves were produced and ED-50 values calculated using probit analysis.

Results

The focus groups identified 21 plants used as anthelmintics in livestock. A general move away from traditional medicines in the younger generation was observed, although when asked if they would use plants in future many would consider this if they had been tested scientifically and were approved by professionals. The five plants shortlisted for in vitro analysis were Acacia nilotica, Cucumis prophetarum, Rumex abysinnicus, Vernonia amygdalinia and Withania somnifera. Three showed efficacy in the EHA; Acacia nilotica, Cucumis prophetarum and Rumex abysinnicus, with EC-50 values of 0.7, 1.1 and 1.3mg/ml respectively.

Conclusion

Three out of five of the plants identified in the PRA showed efficacy in vitro suggesting that plant remedies used by livestock owners in the Oromia region of Ethiopia may contain compounds with genuine anthelmintic activity. Evaluation of current attitudes suggests that plant remedies are not used unless there is no other option, but that they would be considered should scientific evidence of efficacy and safety be presented to them by animal health professionals [3]. It is therefore essential that a randomised controlled trial is used to verify whether in vitro anthelmintic activity can be translated in vivo and thus whether the plants identified in this study have potential as safe alternatives to synthetic anthelmintic drugs. This study has highlighted that local practices pertaining to the health of working equids are a rich source of information that may help to inform sustainable and effective treatment strategies in future.

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.