Appropriate Workloads

INTRODUCTION

An appropriate workload is the total amount of work, in terms of weight carried or pulled, the duration and the intensity of work, that an animal can perform without causing pain, injury, fatigue, or decline in condition. Ability to work depends on multiple factors, including age, species, body condition and conformation, fitness, climate, terrain, quality of equipment, and the type of work. Adequate rest and recovery periods are essential to keep workloads within the equid’s safe capacity (1).

Age and Development

• Start of working life: In accordance with WOAH, Chapter 7.12 (Working Equids), working life should not begin before three years of age; equids continue to develop until over the age of five. Excessive work in young animals increases the risk of permanent leg and back injuries, reducing working life (2). However, gentle and regular human-animal interaction, basic training, and exposure to equipment during this pre-work period are important to build trust, reduce behavioural problems and promote a positive human animal working relationship later in life (7)
• Elderly animals: Workloads should be reduced for older animals due to decreased stamina and the increased likelihood of chronic health issues.
• Pregnant and nursing mares: Special consideration should be given from three months before foaling until at least three months, preferably six months after foaling, to avoid jeopardising pregnancy, to provide for the mare’s increased nutrition and rest requirements, and to allow foals adequate suckling and resting time (3).

Load Limits

• Pack animals: If pack loads are too heavy or imbalanced, it will increase energy expenditure, fatigue and injury risk, and recovery time will worsen significantly. The pack load should be based on a consideration of the working capacity of the individual to prevent overloading the equid (4).
• Pulling work/traction: Consider terrain, gradient, load balance, and cart condition — even small increases in drag can greatly increase strain. Challenging terrain or inadequate hoof care can reduce workload capacity and increase injury risk. Hard, rocky, or uneven surfaces require special consideration when setting loads and work duration, as they increase strain, risk of slips, and hoof damage (5).
• Speed: Rushing or forcing equids into faster paces can increase the risk of injury.

Nutrition

• Access to appropriate nutrition should be considered when deciding on an appropriate workload. Body condition score can indicate whether nutrition is adequate. Equids with a low body condition score may lack the reserves to handle greater workloads (1,2).
• Energy demand will increase with increased workload. Workloads should match the equid’s condition and nutrition status (5).

Hydration

• Equids lose large volumes of fluid and electrolytes when working especially when overloaded and in hot and humid conditions. Dehydration reduces stamina and worsens recovery from effort, so it is important this is a consideration (6).

Recognising Overload

Some signs that may indicate an equid is working beyond their capacity are:

• Reluctance to move or repeated stopping
• Laboured or rapid breathing
• Muscle tremors or drooping posture
• Stumbling, unsteady or irregular gait
• Loss of appetite or weight
• Wounds, harness sores, or swelling
• Behavioural changes such as withdrawal, tail swishing, pinned ears, or avoiding equipment
• Abnormal posture such as head held high or low
• Taking shortened steps and/or slower steps

These signs may also indicate other issues, so need to be interpreted within the context (7).

Horses, Mules and Donkeys

Horses, mules and donkeys may display signs of fatigue such as stumbling, head-lowering, heavy breathing, or stopping. These normal behavioural signs of distress/overloading/overworking can be misinterpreted as problematic behaviour leading to unreasonable punishment of the animal (1). Early signs of musculoskeletal pain or discomfort can be subtle and include changes in gait such as short steps, head tilting or uneven stride. Behavioural cues like pinned-back ears or repeated tail swishing can be early indicators of discomfort or lameness within the working context (9). Donkeys may show similar but less overt signs of pain and distress which handlers may be less likely to recognise. These signs can include reduced interaction and responsiveness or altered mobility. Often, problems are noticed when it is too late (8, 11).

Work, Duration and Rest

Regular Breaks: It is important to allow equids to have regular breaks from work of sufficient length to allow recovery. This should be judged on an individual basis and related to the circumstances and behaviours they are expressing. Continuous work without breaks increases heart rate, respiration rate, and body temperature, leading to heat stress, muscle fatigue, reduced work output and compromised welfare (3, 12) As a minimum, rest breaks should be at least every two hours during the working day, with access to shade and drinkable water (10). Evidence shows that frequent rest breaks reduce the risk of heat stress, improve muscle recovery, reduce cumulative fatigue and improve willingness to work the next day (6). Daily work limit: Monitor and adjust the hours worked per day according to the capacity of the individual and climatic conditions. Weekly rest: At least one full day of rest every seven days; preferably two, depending on the type of work and health of the equid (7).

Weather Adjustments

Reduce work in very hot and humid weather, as heat increases the effort required to regulate body temperature especially when the effectiveness of sweating mechanisms is reduced, and can quickly lead to fatigue or heat stress (11).

Wet, cold, or muddy conditions may also require workload reduction, as moving through slippery or soft ground demands significantly more energy and places extra strain on muscles and joints (12).

WHAT HAPPENS WHEN WORK EXCEEDS CAPACITY?

Compromised Welfare Indicators

Overload and exceeding the equid’s capacity has immediate and long-term effects on equid welfare and productivity:

• Physical injury: Back injuries, joint strain, harness wounds, pressure sores, and chronic lameness (2).
• Heat stress and dehydration: Can lead to collapse or death in severe cases (11).
• Loss of body condition: Energy diverted from recovery to work, causing weight loss and reduced muscle mass (2).
• Reduced working life: Young animals worked too early can develop significant musculoskeletal problems such as angular limb deformities meaning they are likely to suffer for the rest of their working lives, and overworked older animals will have significantly shorter productive lives.
• Behavioural issues: Reluctance to work, refusal to move, or aggressive/avoidance behaviours as signs of pain, distress and fatigue (3, 9).
• Economic loss: Injured or exhausted animals require long recovery times or replacement, increasing costs for owners.
• Reproductive impact: Overworking pregnant or nursing mares can result in miscarriage, poor lactation, reduced fertility or foal mortality (3)

Sick or injured animals should not be worked.

Working them can cause lasting damage, reduce productivity, and shorten their working life, leading to higher costs and loss of income. Reduce or stop work if signs of fatigue or poor condition are observed. Regular health checks should be conducted of gait, appetite, weight, skin and behaviour to help to identify and manage problems early and reduce losses (7).

KEY MESSAGE

Workload affects the productivity and welfare of working equids. Overloading or poor workload management often leads to injury, fatigue, shortened working life, pain, and suffering. To maximize efficiency and sustainability, all factors, such as age, health, terrain, climate, rest, and nutrition, must be carefully balanced to ensure the animal’s capacity is not exceeded (7).