donkey

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.

Typhlocolitis was diagnosed in 40 aged donkeys at routine post mortem examinations subjected to euthanasia for colic-related clinical signs at The Donkey Sanctuary. Gross pathological changes included oedema, ulceration and haemorrhage involving the caecum and ventral colon. Histopathology indicated endoparasite and bacterial associated inflammation in 20 and 11 cases, respectively. Bacterial culture in 18 cases did not yield a definite aetiological agent. Other management and stress related factors were looked at to identify obvious risk factors. This report describes the clinical, biochemical and haematological parameters and pathological changes observed in 40 donkeys diagnosed with typhlocolitis.

Background

Hyperlipemia is a common disorder of the donkey, with mortality rates of up to 80% reported. Such a poor prognosis makes prevention of this disorder or amelioration in the early stages crucial.

Objectives

The objective of this study was to describe and determine the prevalence of hyperlipemia in a population of donkeys and to determine risk factors for development of the disease.

Animals

A total of 449 cases were investigated from a population of 3829 donkeys; donkeys were resident at The Donkey Sanctuary, a charity providing refuge for unwanted donkeys in the UK. Animals were selected on the basis of presence of clinical disease.

Methods

A retrospective case–control study design was used, and all donkeys presenting with hyperlipemia over a 4-year period were included. Each case was matched with 2 controls that had not suffered from hyperlipemia in the previous month. Multivariable analysis was carried out to determine risk factors.

Results

A total of 449 clinical cases of hyperlipemia were reported with an associated mortality rate of 48.5%. Concurrent disease was present in 72% of donkeys and was the greatest risk factor (OR = 76.98); others included cardboard bedding (OR = 3.86), movement (OR = 3.94), weight loss (OR = 6.4), dental disease (OR = 1.73), and concentrate feeding (OR = 1.87).

Conclusions

This study shows that this population of donkeys in the UK often develops hyperlipemia, particularly in response to stress or primary illness, and provides useful insights in to health and management risk factors that may be addressed to decrease the risk of hyperlipemia both in the study population and in other similar donkey populations.

This article provides a review of hoof anatomy and care in donkeys and mules. Hoof disease is a major cause of poor welfare and mortality globally. Problems associated with hoof disease are discussed in the context of behavior, diet, treatment, and prevention. The most common conditions encountered are discussed, including laminitis, the overgrown unbalanced hoof, white line disease, flexural deformities, and other significant issues. Differences between donkey and horse hoof anatomy are described.

Published online ahead of print.

Histopathological examination was carried out on post mortem samples of liver from 12 donkeys (Equus asinus), aged 21-57 years (4 females, 1 stallion, 7 geldings). Variable amounts of haemosiderin were present in Kupffer cells, portal macrophages and hepatocytes in all cases. In all cases there was infiltration of connective tissue around portal tracts by variable numbers of inflammatory cells (lymphocytes, plasma cells and macrophages) but obvious portal fibrosis was present in only four animals. Subjective assessment of overall haemosiderin staining (including extent and intensity) generally reflected biochemical measurements of liver iron content (measured by an inductively-coupled plasma method) as well as quantitative histochemical measurements (using an image analysis package and sections stained with Perl's Prussian blue stain). Accumulation of hepatic iron in old donkeys was not directly related to other pathological changes and may be an incidental finding.

The general prevalence and population composition of gastrointestinal and pulmonary helminths of working donkeys were studied. For the purpose 2935 working donkeys were coprologically examined for nematode and cestode, and 215 donkeys for trematode infections. Seven donkeys that died due to various health problems or were euthanased on a welfare ground were necropsied and the parasites were recovered and identified to the species level. The study was conducted during the periods 1996-1999.

Coprological examination revealed 99% strongyle, 80% Fasciola, 51% Parascaris, 30% Gastrodiscus, 11% Strongyloides westeri, 8% cestodes and 2% Oxyuris equi infection prevalence. Over 55% of donkeys had more than 1000 eggs per gram of faeces (epg). Forty two different species of parasites consisting of 33 nematodes, 3 trematodes, 3 cestodes and 3 arthropod larvae were identified from postmortem examined donkeys. Among the nematodes 17 species of Cyathostominae and 7 species of Strongylinae were identified. Other parasites identified include, Habronema muscae, Draschia megastoma, Trichostrongylus axei, Strongyloides westeri, Anoplocephala perfoliata, Anoplocephala magna, Anoplocephaloides (Paranoplocephala) mamillana, Parascaris equorum, Fasciola hepatica, Fasciola gigantica, Gastrodiscus aegyptiacus, Dictyocaulus arnfieldi, Oxyuris equi, Probstmayria vivipara, Gasterophilus intestinalis, Gasterophilus nasalis, Rhinoestrus uzbekistanicus and Setaria equina. This study revealed that working donkeys in Ethiopia are infected with a range of helminths and arthropod larvae, which are representatives of the important pathogenic parasites found in equids worldwide.

A review of common gastrointestinal disorders of donkeys and mules is presented. Clinically relevant aspects of donkey behavior, anatomy, and physiology are highlighted. Diagnosis, management, and treatment of conditions affecting the gastrointestinal tract from stomach to rectum, including liver and pancreas, are discussed.

Published online ahead of print.

A retrospective study was conducted to investigate the cause of rectal prolapse in working donkeys in Ethiopia. Analysis of data on rectal prolapse cases obtained from the Donkey Health and Welfare Project clinic at the School of Veterinary Medicine, Addis Ababa University, from 1995 to 2004 revealed that 83.6% (n=177) of the cases were associated with Gasterophilus nasalis. The rest 10.7% and 5.7% were associated with work-related (overloading) cause and diarrhoea, respectively. The mean and median numbers of G. nasalis recovered from the rectum of infected donkeys were 66 and 64, respectively, with a range of 2–195. Over 100 G. nasalis larvae were recovered from the rectum of 22% of the donkeys. Circular demarcated ulcer-like and deep circumferential pits or ring-like mucosal lesions were found at the larval attachment sites. G. nasalis infection and the associated rectal prolapse were observed year round. However, the intensity of rectal larval infection and incidence of rectal prolapse were significantly higher during the rainy season (P<0.01). Age and sex of the donkeys had no significant effect on the intensity of rectal larval infection and incidence of rectal prolapse (P>0.05).

An 18-year old jenny was observed with a right maxillary tumefaction, presenting weight loss, quidding, dysphagia and halitosis. An external and intra oral examinations were performed. Both exams revealed a complete blockage of motion in the right mandible, due to the presence of severe shear mouth. A pedunculated mass was observed in the right maxillary vestibular space. It was speculated that the mass resulted from food debris acting as a source of gingival irritation, as a consequence of the shear mouth.

Gingival hyperplasia is a common histological feature in equids, due to close contact between an abrasive diet and oral tissues. However, on a macroscopic level, pathological proliferation of the gingival tissue is uncommon and seldom reaches significant dimensions, but still should be considered differential diagnoses when examining an equid with pertinent clinical signs, mainly when severe dental disorders are diagnosed.

This clinical case seems to be the first describing the occurrence of gingival fibrous hyperplasia apparently as a direct consequence of shear mouth in a donkey.