Five signs of foot rot and how you can stop it
Foot rot is defined as a contagious disease in cloven-hoofed mammals that causes inflammation of the foot and subsequent lameness (Blood and Radositis, 1989). Lameness in all sectors of the beef industry can lead to decreased performance. It is estimated that approximately 20% of lameness in all cattle — dairy and beef — is attributed to foot rot (Step, et al., 2016). However, in the beef industry alone, it is estimated that closer to 75% of all diagnosed lameness in cattle is attributed to foot rot (Currin et al., 2009). Cattle in the feedlot have been reported to have close to half a pound lower average daily gains while they are combating foot rot (Brazzle, 1993). Therefore, foot rot represents a significant economic loss to the industry due to decreased performance.
Bacteria are responsible for the cause of foot rot. The main foot rot-causing bacteria in cattle is Fusobacterium necrophorum, a ubiquitous bacterium found in the environment. Researchers have isolated it on the surface of healthy feet, in the rumen and in the feces of beef cattle. Other bacteria that are present on healthy feet can increase the virulence of F. necrophorum and, therefore, increase the incidence of foot rot (Currin et al., 2009). It is not until there is an injury to the foot — caused by walking on rough surfaces or standing in wet, damp and/or muddy conditions, resulting in a weakening of the foot tissues — that the bacteria sets in and wreaks havoc on the foot. Another common cause of foot rot is when cattle quickly go from wet conditions to dry conditions. This can cause the skin to become chapped and cracked, giving F. necrophorum a chance to enter the tissues of the hoof. Mineral deficiencies in zinc, selenium and copper are also known causes of foot rot (NRC, 2017). Because foot rot can be caused by a ubiquitous bacterium, it is not considered contagious.
Clinical foot rot will present with the following symptoms:
- Extreme pain, leading to the sudden onset of lameness
- Elevated body temperature
- Bilateral swelling of the interdigital tissues, around the hairline and coronary band of the hoof. The swelling may lead to greater-than-normal separation of the claws
- Necrotic lesions in the interdigital space, with a foul odor
- Decreased feed intake
These symptoms can be similar to the symptoms of other foot issues that are common in beef cattle. For example, digital dermatitis, commonly referred to as hairy heel wart, is often mistaken for foot rot when cattle become lame (Step et al., 2016). However, digital dermatitis only affects the skin in the heel bulb area and up to the area of the dew-claw. Digital dermatitis also does not produce a foul odor, is more centralized and is contagious.
Once the proper diagnosis is made, foot rot can be treated. Treatment for foot rot is most successful when completed early, toward the beginning of its onset. The most common method of treatment is via tetracycline antibiotics (Currin et al., 2016). It is crucial to consult a local veterinarian for recommendations about antibiotics and the proper dosage levels. Other common treatments include rubbing a sterilized rope or twine between the animal’s toes to remove the necrotic tissue, followed by applying a topical antimicrobial and simply keeping the foot clean and dry while antibiotic treatment is given.
There are practices that can help reduce the risk of foot rot in a herd. For example, if caused by wet and muddy conditions, ensure proper drainage and the sloping of pastures or barns, such that moisture doesn’t collect in locations where cattle often congregate. Additionally, smoothing rough areas and ensuring that pastures and pens are kept clear of sharp debris that can cause abrasions or scratches to the hooves can help keep foot rot at bay. Simply ensuring that cattle are fed proper levels of minerals has shown to reduce the incidence of foot rot. Zinc is known to be critical for maintaining the integrity of the skin and hoof (NRC, 2016); thus, zinc should be fed at proper levels — and even elevated levels, if foot rot is known to be a common issue (Kellems and Church, 2010). Organic complexes of zinc are commonly included in beef diets at normal levels. However, with the increased bioavailibity of zinc in its organic form, it is wise to ensure the proper zinc status of the herd to reduce the incidence of foot rot. Although iodine is not known to be a mineral involved directly in foot integrity, dietary EDDI, a common source of iodine used in mineral supplements and premixes, has shown to be beneficial in the prevention of foot rot.
Foot rot is a significant cause of lameness in beef cattle and can result in a major economic and production loss in some herds. Although foot rot-causing bacteria can be found everywhere and are sometimes unavoidable, quick treatment early on and practicing proper pasture and pen maintenance can help to reduce the chances of clinical foot rot in beef cattle. Also, making sure the zinc and iodine levels are properly maintained during all stages of production in forms such as EDDI and organic complexes such as Alltech’s Bioplex Zinc can maximize protection against foot rot.