Obesity is a significant welfare problem and may predispose donkeys to several diseases (Morrow et al., 2011). Causes of obesity include an inappropriate diet, lack of exercise, issues with other donkeys, separation grief and equine metabolic syndrome (EMS) (Burden and Bell, 2019).
This article will explore the role of the registered veterinary nurse (RVN) in weight management programmes for donkeys.
Equine metabolic syndrome
EMS is a relatively common disorder seen in donkeys that can predispose them to obesity and laminitis. EMS begins with an error in insulin regulation and, subsequently, an elevation in insulin concentration in the blood serum. Without intervention, levels of insulin continue to rise, causing hyperinsulinaemia. Long-term insulin elevation as a result of EMS can cause chronic changes such as irreversible damage to the hooves due to secondary laminitis.
Clinical signs include recurrent or acute laminitis and regional adiposity/fatty deposits on the rump and/or crest. EMS should be diagnosed by a veterinary surgeon using a baseline insulin blood test, and treatment for donkeys includes a combination of changes in diet and exercise.
Donkeys with EMS should be managed following the same dietary programme as a potentially laminitic or overweight donkey. When altering a donkey’s diet to facilitate weight loss, changes must be gradual to ensure the risk of hyperlipaemia is minimised. Administration of further medication may be required if initial management changes are unsuccessful – this will be at the discretion of the treating vet.
This type of management change can be difficult for owners to implement. The RVN can assist with this by providing help and guidance either as a point of contact at the practice or in an ambulatory role by going out and helping the owner directly at the yard.
Assessment of weight and body condition scoring
It is important for owners to know how to assess the weight of an obese donkey; the most accurate way to assess this is to use a correctly calibrated electronic weighbridge. However, most owners do not have access to this type of equipment (Burden and Bell, 2019).
Horse weigh tapes are inaccurate for donkeys (Barrio et al., 2019). Therefore, donkey-specific weigh tapes should be used to estimate the weight of a donkey. The RVN can teach the owner how to use the weigh tape and encourage them to purchase one. The donkey’s weight can then be monitored over time. This will give an indication of any trends. Any increase or decrease in weight can be identified quickly and interventions can be put in place.
Another way to assess the weight of a donkey is to perform a body condition score (BCS). A BCS for a donkey requires a different technique to that used on horses as donkeys accumulate fat stores in more localised areas and have a different body shape (Burden, 2012). The donkey has an angular frame alongside a pendulous abdomen, often incorrectly described as “pot-bellied” (Burden, 2012).
Donkeys accumulate fat stores in more localised areas and have a different body shape. The donkey has an angular frame alongside a pendulous abdomen, often incorrectly described as ‘pot-bellied’
The Donkey Sanctuary has developed a BCS system for donkeys. Five specific areas are assessed: neck and shoulders, withers, ribs and belly, back and loins, and hindquarters (Burden and Bell, 2019). The donkey is allocated a number following the BCS with five being obese and four overweight.
The RVN can teach the owner how to carry out a BCS for their donkey. Performing a BCS monthly and recording the measurements is recommended; this will enable the BCS to be monitored over time. Interventions can then be implemented with support and advice from the vet and the RVN.
Estimating weight
The weight of the donkey can also be estimated using The Donkey Sanctuary’s weight estimator. This is calculated using two measurements: the height of the donkey and a measurement of their heart girth area. The height measurement is taken using a measuring stick and is read off at the highest point of the withers. The heart girth measurement is taken by passing a measuring tape around the bottom of the donkey’s chest as far forward and as close to the front legs as possible (TDS, 2014).
The height and girth measurements can then be marked on the weight estimation chart, and the donkey’s estimated weight can be read from the centre scale by drawing a line between the two measurements (TDS, 2014). The heart girth measurement should always be taken in the same location and by the same person to ensure consistency of the readings. The RVN can assist with this by showing the owner how to carry out measurements correctly.
The heart girth measurement should always be taken in the same location and by the same person to ensure consistency of the readings
Feeding the overweight donkey
Dieting overweight donkeys is difficult and requires veterinary advice (Burden, 2012). If the donkey has no specific dental issues, dietary management should focus on barley straw with limited grazing in the warmer months (Burden and Bell, 2019). Straw with limited hay and grazing can be given in the colder months. If there are concerns over nutritional deficiency, vitamin and mineral supplements designed for equids can be given in appropriate quantities (Burden and Bell, 2019).
Turnout should only be provided in cases where there is no active laminitis present. Pasture management should be instigated in the form of strip grazing with a guide of less than 0.2 acres per donkey of short, cropped pasture (Burden and Bell, 2019).
If the donkey has no specific dental issues, dietary management should focus on barley straw with limited grazing in the warmer months
A track system could also be introduced to encourage more movement. This involves fencing to create a track of three to four metres wide through the donkeys’ environment (TDS, 2014). The donkeys are free to move and graze only within this track area. Donkeys move much further using the track system, which will help to encourage weight loss. The RVN can help with this by going out to the yard and advising the owner on how best to implement a track system after seeing the available facilities.
When dieting donkeys, progress may be slow, and perseverance is essential for a favourable outcome. A reasonable aim would be to lose 2 to 3 percent of body weight monthly (Burden and Bell, 2019). Rapid weight loss should be avoided owing to the risk of developing hyperlipaemia.
The RVN can assist by helping the owner monitor the weight loss to make sure that it happens at a healthy rate. If weight loss is not progressing as it should, the RVN can help the owner to implement further changes and increase the chances of a successful outcome. The RVN should keep the case vet updated to enable changes to the treatment plan to be made in a timely manner.
Conclusion
Assessing and managing weight in obese donkeys is essential to maintain health and to prevent or help manage associated conditions. The RVN can help the owner to implement a successful weight loss programme by providing advice and guidance with weigh taping, weight estimation or body condition scoring. The RVN can also help the owner implement safe and successful dietary management strategies. Support from the RVN and regular input from the case vet will enable the owner to maintain concordance with the treatment plan and achieve the best outcome for the patient.
