laminitis

Laminitis in donkeys compared to horses - Recognition, treatment and prevention

Alexandra K. Thiemann
Presentation date

Laminitis is a relatively common, painful condition of donkeys, ponies and horses. The underlying principles of pathology, diagnosis and treatment are broadly similar, but there are features of donkey anatomy, behaviour and physiology that differ from the horse; understanding these will improve treatment outcomes (Thiemann et al, 2021).

A study of over 2500 donkeys in the UK, found a prevalence of 4% of donkeys presented with laminitis with 46% of cases acute and 54% chronic. This is likely to be an underestimate due to the high levels of obesity and poor detection of the disease.

Recognition of laminitis

Few donkeys in Europe work, most are companion equines. This often results in late detection of laminitis in this species. Typically, signs are subtle, and include altered posture, stiff or shuffling gait and lameness on turning. There may be increased digital pulses and pain to hoof testers. Many donkeys will just lie down, and some owners can misinterpret this as normal resting behaviour.

In chronic cases, there will be abnormal growth rings on the hoof, a flatter sole and, in severe cases upper limb muscle atrophy and flexor tendon breakdown.

Using the Donkey Facial and Donkey Composite pain score (Van Dierendock, et al 2020) enables clinicians to quantify donkey pain and monitor response to treatment and analgesia.

The anatomy of the donkey hoof varies from the horse- P3 sits further distal and there is typically 10mm “founder distance” as normal between the coronary band, and top of the extensor process. The frog tissue is further back on the distal border of P3, this makes use of a heart bar shoe inadvisable. A normal hoof should have at least 10mm sole depth. The external hoof wall is approximately 5° more upright than a horse, but the phalanges, pastern and dorsal hoof wall should align.

Radiographs of donkey hooves need interpreting using donkey parameters.

Obese donkeys suffer from Asinine Metabolic Syndrome (AMS) and donkeys with Body Condition Score >3 (scale 1-5) are at risk. Donkey specific BCS charts and weight nomograms are available (The Donkey Sanctuary, 2020a & 2020b) to assist with assessment. Basal insulin and karo lite testing can be used to confirm a diagnosis of AMS.

Elderly donkeys can develop PPID and, as in the horse, seasonally adjusted donkey specific reference ranges are available.

Treatment of laminitis

As in the horse, the basis of treatment consists of rest, analgesia, foot care and dietary adjustments. In the donkey acute pain and stress, or rapid change in diet may precipitate life- threatening hyperlipaemia (Burden et al, 2011). Ensure the donkey’s appetite and demeanour are closely monitored, and while it is appropriate to reduce the sugar content of any fibre being fed, a reduction in fibre or attempts to diet an obese donkey should be done in a gradual manner.

Donkeys metabolise all NSAIDs (except carprofen) faster than horses, and after a loading dose of 4.4mg/kg BID of phenylbutazone, long term use at 2.2mg/kg BID is considered safe with less risk of dorsal colon ulceration. Meloxicam has a short half- life in donkeys (6 hours) and there is little data on newer NSAIDS. Paracetamol is a useful adjunct at 20-25mg/kg BID. Miniature donkeys require TID dosing for adequate analgesia.

Digital hypothermia is well -tolerated by donkeys and can be useful in acute cases or as preventative in sepsis cases.

In acute cases foot support is best provided with a deep bed, and whole hoof padding or using a commercially available sole support.

Corrective farriery after an episode is an important part of rehabilitation of the hoof, and for chronic cases with flat soles the use of acrylic rim shoes may assist in providing comfort.

Medical support for underlying AMS or PPID is similar to in the horse. The Donkey Sanctuary has little experience yet with the use of levothyroxine to aid weight loss, or insulin lowering drugs such as ertuglifloxin. Pergolide for the reduction of ACTH is known to cause appetite suppression in some donkeys, so when used, the donkey needs careful monitoring.

Prevention of laminitis

Preventative medicine in donkeys is often poor (Barrio et al, 2020), and engaging with owners about correct nutrition, weight management and farrier care is a good strategy. The Donkey sanctuary provides an online resource “The Donkey Academy” with free courses for owners, vets and farriers to assist in this area, as well as fact sheets and handbooks: https://www.thedonkeysanctuary.org.uk/research/what-we-do/knowledge-and-advice/donkey-academy

Donkeys with good dentition cope well on a high fibre, low starch diet where straw provides the bulk of the forage, supplemented by a small amount of vitamin/mineral balancer (Burden et al, 2019). If dieting is needed, suitable mental stimulation helps with prevention of stereotypic behaviour developing (The Donkey Sanctuary, 2020c).

In many cases severe chronic laminitis is undetected and vets and owners can work together to understand the impact of this on Quality of life and End of life Decision-making. The stoic nature of donkeys can results in prolonged unacceptable suffering.

References

1) Thiemann, A. K., Buil, J.and Rickards, K.(2021). A review of laminitis in the donkey. Equine Veterinary Education. 34(10) 553-560. Available from: doi.org/10.1111/eve.13533

2) Van Dierendonck M.C., Burden, F.A. and Rickards, K. (2020). Monitoring acute pain in donkeys with the Equine Utrecht University Scale for Donkeys Composite Pain (EQUUS-DONKEY-COMPASS) and the Equine Utrecht University Scale for Donkey Facial Assessment of Pain (EQUUS-DONKEY-FAP) Animals.10(2) 354. Available from: doi.org/10.3390/ani10020354

3) The Donkey Sanctuary (2020a) Donkey Body Condition Score chart. Available from: https://www.thedonkeysanctuary.org.uk/research/sites/uk/files/2020-01/body-scoring-chart-revised-01-2020.pdf.

4) The Donkey Sanctuary (2020b) Donkey weight nomogram. Available from: https://www.thedonkeysanctuary.org.uk/research/sites/uk/files/2020-01/donkey-weight-estimator-chart-revised-january-2020.pdf

5) Burden, F. A., Du Toit, N., and Hazell-Smith, E. (2011). Hyperlipaemia in a population of aged donkeys: description, prevalence, and potential risk factors. Journal of Veterinary Internal Medicine. 25(6)1420-5.

6) Barrio, E., De Blas Giral, I., Thiemann, A. K. and Vasquez Bringas, F. J. (2020) Demography, preventative health care and reasons for relinquishment of donkeys to an equine charity. Equine Veterinary Journal. 53(2) 324-330. Available from: doi.org/10.1111/evj.13310

7) Burden, F. A. and Bell, N. (2019) Nutrition and Malnutrition of donkeys. Veterinary Clinics of North America Equine Practice 35(3) 469-479.

8) The Donkey Sanctuary (2020c). Environment Enrichment: The Donkey Sanctuary’s Guide to Enriching the Lives of Donkeys and Mules. Available at: https://view.pagetiger.com/EnvironmentalEnrichmentforDonkeys/EnvironmentEnrichmentfordonkeys [Accessed September 19 2020].

Management of laminitis in the donkey

Alexandra K. Thiemann
Presentation date

Laminitis is seen relatively frequently in first opinion equine practice and affects all breeds of horse, pony and donkey. Studies in the UK of companion donkeys  gives a prevalence that approximately 4% of donkeys suffered a laminitic episode in the preceding 12 months, of which 54% were chronic cases and 46% acute.

While there are many similarities in the diagnosis, management and treatment of laminitis in donkeys and horses, knowledge of the species specific differences will provide better treatment for donkey patients. This presentation will cover how to recognise laminitis in the donkey, and the treatment and management of acute and chronic cases.

Country

Emergency management for donkeys and mules

This article provides an overview of initial assessment and management of common emergency presentations in donkeys and mules. The principles are similar to those in horses (and ponies), but clinicians must be aware of differences in recognition of signs of pain/disease, approach to handling, pharmacology of some drugs, and subtle differences in the physiology and local anatomy in donkeys and mules. The epidemiology of common disease presentations will vary between pet/companion or working/farmed donkeys and mules. Regular dental checks, deworming, vaccination, and monitoring of behavior and quality of life are important aspects of preventive care.

Volume
37
Issue
2
Start page
495
End page
513
Publication date

A review of laminitis in the donkey

Laminitis is a commonly occurring, painful condition of the foot that can have a major impact on the welfare of affected donkeys. When faced with a donkey suspected to have laminitis, the approach is broadly similar to that in the horse, however there are certain factors unique to donkeys that this article aims to highlight including: the differences in use, behaviour, anatomy, therapy and management.

Publication date
Country

Radiological anatomy of the donkey's foot: Objective characterisation of the normal and laminitic donkey foot

Reason for study

Anatomical change within a laminitic foot is of diagnostic and prognostic importance. A lateromedial radiograph represents the current 'gold standard' by which these changes are identified. Detection of anatomical change is dependent upon a priori knowledge of normality and subjective assessment alone may not identify modest change. Normal baseline data is, therefore, needed against which objective comparisons can be made. There is little information regarding the radiological anatomy of the donkey foot, hence an equine model has been widely adopted. However, descriptive accounts suggest fundamental anatomical differences between these 2 species.

Objectives

To characterise objectively the radiological anatomy of normal donkey feet and define the nature and extent of anatomical change associated with laminitis.

Methods

The anatomy of the forefoot was quantified from lateromedial radiographs of 83 normal and 74 laminitic donkeys, using a computer based imaging system. Data were analysed using univariate and bivariate statistical methods.

Results

Baseline data were established that define the radiological characteristics of the anatomy of normal donkey feet. The key hoof, bone and weightbearing stance parameters of lateromedial radiographs have been evaluated. Laminitis was associated with significant rotation and distal displacement of the distal phalanx, increases in integument depth and morphometric change to the distal phalanx (P<0.05).

Conclusions

This study challenges the validity of applying an equine model to the radiological anatomy of donkey feet. Hence, the diagnosis of anatomical change cannot be based on baseline data previously given for the horse and guidelines should be revised accordingly for the donkey.

Potential relevance

This study provides an objective basis for the identification of anatomical change associated with laminitis in donkey feet.

Volume
43
Issue
4
Start page
478
End page
486
Publication date

Laminitis in donkeys: a pilot study investigating radiographic versus post-mortem measurements

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.

Volume
51
Issue
S53
Start page
10
End page
10
Publication date
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Hoof disorders and farriery in the donkey

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.

Volume
35
Issue
3
Start page
643
End page
658
Publication date
Country

Donkey hoof disorders and their treatment

Disorders of the hoof have important health and welfare implications in donkeys. Clinical conditions that affect the donkey hoof include laminitis, which is one of the most common causes of lameness in donkeys in the UK, as well as white line disease/abscess, and chronic conditions such as overlong hooves. This article reviews the normal anatomy and function of the donkey’s foot, before discussing in more detail the diseases that can arise and their treatment.

Journal
Volume
35
Start page
135
End page
140
Publication date
Country

Development of a quantitative multivariable radiographic method to evaluate anatomic changes associated with laminitis in the forefeet of donkeys

Objective

To establish and validate an objective method of radiographic diagnosis of anatomic changes in laminitic forefeet of donkeys on the basis of data from a comprehensive series of radiographic measurements.

Animals

85 donkeys with and 85 without forelimb laminitis for baseline data determination; a cohort of 44 donkeys with and 18 without forelimb laminitis was used for validation analyses.

Procedures

For each donkey, lateromedial radiographic views of 1 weight-bearing forelimb were obtained; images from 11 laminitic and 2 nonlaminitic donkeys were excluded (motion artifact) from baseline data determination. Data from an a priori selection of 19 measurements of anatomic features of laminitic and nonlaminitic donkey feet were analyzed by use of a novel application of multivariate statistical techniques. The resultant diagnostic models were validated in a blinded manner with data from the separate cohort of laminitic and nonlaminitic donkeys.

Results

Data were modeled, and robust statistical rules were established for the diagnosis of anatomic changes within laminitic donkey forefeet. Component 1 scores ≤ −3.5 were indicative of extreme anatomic change, and scores from −2.0 to 0.0 denoted modest change. Nonlaminitic donkeys with a score from 0.5 to 1.0 should be considered as at risk for laminitis.

Conclusions and clinical relevance

Results indicated that the radiographic procedures evaluated can be used for the identification, assessment, and monitoring of anatomic changes associated with laminitis. Screening assessments by use of this method may enable early detection of mild anatomic change and identification of at-risk donkeys.

Volume
73
Issue
8
Start page
1207
End page
1218
Publication date
Country
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