Foot Pad Dermatitis in Turkeys

Foot pad dermatitis is a condition characterized by lesions on the foot pad of turkeys, which, when severe, lead to the erosion of the skin layers and cause pain when weight is put on the foot.  Scoring scales used at the processing plant to determine the severity of the lesions can be used as an indication of welfare of a flock, due to the pain associated with this condition, making it a management aspect which should be monitored very closely.  Additionally, the pain caused by foot pad dermatitis leads to decreased mobility which may cause a decrease in eating and drinking, as it is too painful to walk to the feed and water lines.  Many factors, including management and nutrition, may contribute to the development and severity of foot pad dermatitis and can be manipulated to reduce the incidence of foot pad dermatitis in a flock.  It is important to be aware of all factors contributing to foot pad dermatitis and manage the barn to ensure these risk factors are being minimized before any lesions appear on the foot pad of the bird.

LITTER MATERIAL
The moisture of the litter used for bedding in a turkey barn is the most important contributor to foot pad dermatitis in turkey flocks.  This is because increased litter moisture facilitates the softening of the foot pad, making it more susceptible to bacterial invasion.  This bacterial invasion leads to the production of a lesion on the foot pad.  In general, other factors involved in the development of foot pad dermatitis are simply related to the way in which they contribute to increased litter moisture.  This includes the litter material being used.  Understanding the ability of that material to hold water and keep it away from the foot pad of the turkey, thereby decreasing the moisture of the litter in contact with the foot pad, is important as making the decision on litter material and depth is an important aspect of barn management.  The litter material may also induce the development of a lesion based on the physical properties of the material, as an abrasive material may cause irritation to the foot pad.  

VENTILATION AND HUMIDITY
The barn environment is influenced by a variety of management factors including humidity, ventilation, and temperature.  Ensuring the humidity is low enough to reduce the litter moisture helps prevent the development of foot pad dermatitis in the turkeys, while still keeping the humidity high enough to prevent the barn from become dusty.  Managing ventilation in such a way that relative humidity levels are maintained between 50 and 70 per cent is a key component of managing to reduce the incidence of foot pad dermatitis in the flock.  This is particularly difficult in the winter, as adding heat is expensive which may cause a producer to decrease ventilation rates to save on heating costs.  Lowering the ventilation in the winter allows for the buildup of moisture within the barn and promotes wet litter, making the flock more susceptible to the development of foot pad dermatitis.  A too high ventilation rate can also have negative effects as this will increase the heating cost to unnecessarily high levels during the winter months. Higher stocking density will put more pressure on litter management due to increased excreta output per square metre. Finding the balance in ventilation that allows for a sufficient quantity of fresh air and removal of moisture from the barn, while keeping heating costs as low as possible, is required to manage the barn and the flock to their potential.  

WATER LINE MANAGEMENT
The management of the water lines in the barn can contribute to the development of foot pad dermatitis in a turkey flock by contributing to increased litter moisture.  Regularly checking water lines for leaks, ensuring they are set to the correct pressure, and maintaining water sanitation in the barn helps to minimize water spillage.  Additionally, ensuring the water lines are at the right height such that the turkeys are not stretching or bending down to drink decreases the amount of water being wasted during drinking and contributes to keeping the litter dry.

BIRD HEALTH
Bird health plays a very important role in the development of foot pad dermatitis.  Disease challenges, such as coccidiosis and enteritis, are associated with malabsorption in the gut, leading to loose excreta and increased litter moisture.  Watery, foamy droppings are often the first indication of a disease challenge. Enteric diseases lead to a decrease in feed and water intake, which results in marginal intake of nutrients critical to health, including energy, amino acids, vitamins and trace minerals. Unless quickly addressed, litter conditions will deteriorate and birds will develop dirty feathering and lethargy.  The combination of these factors results in impaired immune response, increasing the turkey’s susceptibility to foot pad dermatitis. Closely monitoring flock health and mortality for the duration of the growing period is very important and should be done in consultation with your flock veterinarian.

NUTRITION
Components of the ingredients provided in the feed can contribute to foot pad dermatitis.  Ingredients containing difficult to digest carbohydrates, such as soybean meal, corn distillers grains with solubles, barley and wheat, are associated with sticky droppings due to their ability to retain water in the excreta.  These sticky droppings are concerning as they increase the contact time of the foot pad with the excreta, as well as increasing the water contained in the excreta.  This challenge can be overcome with enzyme supplementation in the diet.  Another nutritional component is the quality and balance of protein being supplied in the diet.  A diet that is poorly balanced in terms of protein leads to increased excretion of water into the litter, contributing to an increase in litter moisture.  The presence of mycotoxins in the feed can also contribute to the development of foot pad dermatitis. The Fusarium mycotoxin deoxynivalenol (vomitoxin), has been shown to disrupt the intestinal mucosa structure, leading to impaired nutrient absorption and contributing to the development of malabsorption and increased excreta moisture. The risk from mycotoxins can be mitigated by stringent screening of feedstuffs and nutritional support to minimize their negative effects. Another dietary factor is sodium intake from both feed and water as it impacts electrolyte balance. Sodium intake in excess of nutritional requirements can contribute to the development of foot pad dermatitis through increased excreta moisture. Maintaining moderate, but adequate, levels of sodium in the diet, with adjustment for the contribution from drinking water, is a necessary step in foot pad dermatitis prevention.  Proper nutrition and feed formulation can address many of the factors involved with foot pad health in turkeys. Developing a nutritional strategy to prevent the development of foot pad dermatitis in your flock should be done in consultation with your flock nutritionist.

CONCLUSION
The effect of litter material, ventilation and humidity, water line management, bird health, and nutrition on foot pad dermatitis needs to be well understood by producers to minimize the risk of this disease developing within their flock of turkeys.  Understanding how these factors work both independently, as well as the way they interact, to induce and increase severity of foot pad dermatitis in a turkey flock gives producers the opportunity to manage their barns to reduce the risk factors present to the turkeys, from day-old poults through to market age.  Barn and flock management that focuses on the reduction of foot pad dermatitis risk factors, particularly by monitoring litter moisture, will contribute significantly to producing a high performing, healthy flock of turkeys.