donkey

Hyperlipaemia is a disease resulting from excessive mobilisation of triglyceride stores such that plasma clearance processes become overwhelmed. Consequently increased plasma triglyceride concentrations (>5.6 mmol/l), visibly cloudy plasma and a sick, anorexic or hypophagic subject follow. Epidemiological studies have identified many predisposing and triggering factors and the attentive carer or veterinary surgeon should be alert to such risk factors so that the disease can be prevented, or at least identified and treated at an early stage. Hyperlipaemic subjects are invariably in a negative energy balance, and nutritional management therefore plays a central role in both the prevention and resolution of the disease.

The domestic donkey is descended from wild asses and has evolved to live in some of the most inhospitable places on earth. Little research has been carried out to address the specific needs of the donkey, which has traditionally been viewed as a small horse. The donkey is different from the horse in many ways; of particular note is its ability to thrive on highly fibrous feeds. This article discusses the nutritional requirements of donkeys and how dental disease may play a role in determining their nutritional requirements.

There is no information about the prevalence of gastric ulceration in donkeys or potential risk factors for its presence in donkeys. The donkey is a stoic, hardy animal that has not previously been thought to suffer from this disease. However, gastric ulceration was found to be a problem in a population of non-working UK donkeys resident at the Donkey Sanctuary and its prevalence was estimated by examining necropsy data over a 2-year period during 2005 to 2006. Associations with clinical and management factors were determined. In total, 426 donkeys were examined at necropsy to determine the presence of gastric ulceration. Lesions were described and scored according to a four-point scale. Management and clinical data from these donkeys were analysed to identify potential risk factors for the presence of gastric ulceration. Terminal blood samples were also studied to determine whether animals were exhibiting hyperlipaemia prior to death. Results showed that 41% (n = 174) of the donkeys studied had evidence of gastric ulceration at necropsy. Most (49%) of the ulcers were of a medium size (area of xs2A7E2 cm2 – <10 cm2) and the most common site for ulcers was the margo plicatus. Of the donkeys examined, 18% had hyperlipaemia prior to or death or euthanasia and this was a risk factor for donkeys developing gastric ulceration; 62% of hyperlipaemia cases also displayed gastric ulceration (P < 0.001). Kidney disease was a potential risk factor (P = 0.02), with 74% of these animals having gastric ulceration. Donkeys that died or were euthanased due to respiratory disease were at a decreased risk of developing ulceration (P = 0.01) Donkeys fed a carbohydrate-based diet were more likely (P < 0.001) to have gastric ulceration than those fed a fibre-only diet, with 55% having gastric ulceration compared with 33% in the fibre-only group. This study has shown that gastric ulceration is commonly observed in donkeys at necropsy and may be extensive.

Reason for study

There is limited information on the gross tracheal morphology of donkeys with or without tracheal abnormalities.

Objectives

1. Examine the morphology of tracheas of donkeys with and without clinical and/or post mortem evidence of tracheal obstruction
2. Record the cross-sectional dimensions and shapes of tracheal rings at fixed sites
3. Document prevalence, sites and characteristics of detected tracheal abnormalities.

Methods

The tracheas of 75, predominantly aged (median age 30 years, range 7-48 years) donkeys that died or were subjected to euthanasia on humane grounds were examined. Five had severe dyspnoea due to tracheal obstruction (with intercurrent lung disease in 3), while 7 had post mortem evidence of severe tracheal airway obstruction. Every 5th tracheal ring was dissected free and the inner and outer vertical and transverse dimensions and cross sectional areas were measured. Each dissected ring was photographed and the shape of the trachea was classified as normal or, in one of 6 abnormal grades, according to the type and degree of structural abnormality present.

Results

The tracheas had a mean of 43 (range 34-50) tracheal rings that tended to be more oval in shape in the distal cervical region. Only 31.2% of rings examined had a circular to oval shape. Dorso-ventral flattening was present in 0.9% of tracheal rings, dorsal ligament separation in 24.4%, slight cartilage deformity in 26.0%, moderate cartilage deformity in 10.4%, marked cartilage deformity in 1.9% and miscellaneous other abnormalities in 4.9% of tracheal rings. The 12 donkeys with ante or post mortem evidence of tracheal obstruction had significantly increased tracheal abnormality grade in comparison to the remaining donkeys.

Conclusions and potential relevance

Structural tracheal abnormalities are present in most old donkeys, but generally do not cause clinical problems in these sedentary animals unless intercurrent pulmonary disease is present.

Objective pain assessment in donkeys is of vital importance for improving welfare in a species that is considered stoic. This study presents the construction and testing of two pain scales, the Equine Utrecht University Scale for Donkey Composite Pain Assessment (EQUUS-DONKEY-COMPASS) and the Equine Utrecht University Scale for Donkey Facial Assessment of Pain (EQUUS-DONKEY-FAP), in donkeys with acute pain. A cohort follow-up study using 264 adult donkeys (n = 12 acute colic, n = 25 acute orthopaedic pain, n = 18 acute head-related pain, n = 24 postoperative pain, and n = 185 controls) was performed. Both pain scales showed differences between donkeys with different types of pain and their control animals (p < 0.001). The EQUUS-DONKEY-COMPASS and EQUUS-DONKEY-FAP showed high inter-observer reliability (Cronbach’s alpha = 0.97 and 0.94, respectively, both p < 0.001). Sensitivity of the EQUUS-DONKEY-COMPASS was good for colic and orthopaedic pain (83% and 88%, respectively), but poor for head-related and postoperative pain (17% and 21%, respectively). Sensitivity of the EQUUS-DONKEY-FAP was good for colic and head-related pain (75% and 78%, respectively), but moderate for orthopaedic and postoperative pain (40% and 50%, respectively). Specificity was good for all types of pain with both scales (91%–99%). Different types of acute pain in donkeys can be validly assessed by either a composite or a facial expression-based pain scale.

Mules and hinnies are hybrid offspring of donkeys (Equus asinus) and horses (Equus caballus). Little scientific information is known regarding mules and even less is known about hinnies, the reciprocal cross. Conformation standards are in place for horses but currently are not available for equid hybrids or donkeys. Conformation maybe related to functionality and longevity of equids. All animals in this study were of similar genetics (Zamora Leones and Mirandes donkey breeds and Spanish horses) from Toro, Spain and Miranda do Douro, Portugal and used for traction.

Limited information is available about the actual management characteristics of dairy donkeys in Southern Europe. The aim of the present study is to describe animal management of dairy donkey farms in Italy. Twelve farmers were asked to answer a questionnaire on the management of their animals and their farms distributed over the Italian territory. Six farms grouped their animals in paddocks according to the production characteristics (e.g. lactating, dry, stallions); three farms housed the stallions in single boxes. Most of the visited farms were family run and the number of animals cared for by a single person varied from five to 103 animals. All the farms but one performed mechanical milking with a modified goat milkmaid.Vaccinations were regularly performed only on two farms. All the foals received colostrum and suckled from their own mothers. Foals were nursed by their mother until 6-12 months old. During the separation period before milking, foals were usually (83%) housed in paddocks near their mothers with the possibility of visual and/or tactile contact, however such separations could be for up to 12 hours (17%). Even though the assessed sample was small, considerable differences were seen between farms, likely due to lack of uniform information available for the farmers. The adoption of scientific based procedures is suggested in order to improve both animal welfare and milk quality.

Background

Laminitis is a painful disease of equines. Radiographic and post-mortem evaluations of feet are often an important part of welfare investigations, and professional opinions by veterinarians are necessary in resulting legal cases. Any difference in measurements between the two modalities can cause uncertainty, potentially affecting the legal decision.

Objectives

To quantify the difference between radiographic and postmortem pre-mortem vs. post-mortem effects.

Study design

Case series.

Methods

Seven donkeys with laminitis confirmed via standard workup, euthanased for reasons unrelated to the study, were selected. Weight-bearing and non-weight-bearing lateral radiographs were taken of both front feet within 24 h pre-mortem. Feet were removed and sagitally sectioned between 48 and 72 h post-mortem. Lateral radiographs were taken of the feet immediately following sectioning. Founder distance and rotation were evaluated at each time point and compared using paired t-tests (P < 0.05).

Results

Compared with pre-mortem weight-bearing radiographs, nonweight-bearing feet had a decreased founder distance and decreased rotation. Compared with pre-mortem non-weight- bearing radiographs, post-mortem feet had increased rotation and no change in founder distance. There were no significant differences between post-mortem direct measurements and post- mortem radiographs. Compared with standard weight-bearing radiographs, post-mortem measurements had a decreased founder distance and increased rotation.

Main limitations

Small sample size. Further samples are needed to confirm these initial conclusions.

Conclusions

Measurements of post-mortem feet have a decreased founder distance and an increased rotation compared with standard radiographic images. Changes in founder distance are seen due to changes in weight-bearing. Changes in rotation are seen post-mortem, and can be explained by autolysis of the laminae and/or rigor mortis causing tendon contracture. Most studies have focused on indications and severity of laminitis in living animals using radiographs: postmortem measurements should therefore be interpreted with caution.

Competing interests

None declared.

Ethical animal research

Approved by The Donkey Sanctuary. Donkeys were owned by The Donkey Sanctuary and were used with consent.

Sources of funding

The Donkey Sanctuary.