Causes & Types of Lameness

Emerging causes of lameness, including digital dermatitis and toe tip necrosis, are becoming better understood, as are the multiple inter-related causes of lameness. For example, when nervous cattle (which may be attributed to genetics) scramble on hard flooring, they may damage the sole of the foot (injury), allowing bacteria to enter and colonize the foot (infection). Each of these types of lameness are associated with specific risk factors. Trauma or wet conditions that affect skin or hoof integrity can cause lameness directly and also provide an avenue for bacteria to enter and colonize a wound.          

Toe tip necrosis is a lameness condition affecting the hind feet of feedlot cattle. It develops early in the feeding period, and often occurs within clusters of animals or cohorts. Sometimes referred to as a toe abscess or ulcer, apical white line disease, or P3 necrosis, it has been associated with improper processing or handling, abrasive flooring, as well as flighty animal behaviour. Careful, low-stress handling and proper flooring may help prevent the development of toe tip necrosis.  

The symptoms of toe tip necrosis can be similar to injury, making it challenging to obtain a definitive diagnosis. It is a very painful conditionas discussed in a recent webinar (skip ahead to 41:20). 

Recent research found that the disease seems to occur from the outside in. The disease starts when the white line between the sole and the hoof wall separates, allowing bacteria to penetrate into the foot reaching into the corium, which is a very sensitive tissue. Inflammation of the corium causes pain, which is made worse if the infection continues into the foot and infects the P3 (coffin) bone.

Current research is examining the impact of different treatment protocols for toe tip necrosis on different weight classes of cattle, as well as combining pain relief products. Carefully trimming the toe tips to allow the infection to drain and reduce pressure on the area is also being explored as a better way to manage the impacts of the disease. 

Pressure builds as an abscess forms in the toes of a hind foot when toe tip necrosis infection is present. (Photo courtesy of Murray Jelinski).

A cross-section of the hoof demonstrates separation between the hoof wall and the white line in an animal affected by toe tip necrosis. (Photo courtesy of Murray Jelinski).

Digital Dermatitis

Digital dermatitis, also known as hairy heel wart or strawberry foot rot, is a skin infection that affects the area around the dewclaws, between the claws, and sometimes the heel of the hooves. The disease is characterized by raised lesions often located between the claws and dewclaws. These lesions are very painful, may appear red and bleed easily if disturbed, and some may have long fibrous hairs. Animals appear to walk on their tip toes to avoid putting pressure on their heels.

Digital dermatitis is highly infectious but doesn’t respond well to injectable antibiotic treatment. Once an animal is infected with Treponema, the organism primarily associated with digital dermatitis, the animal will have it for life. To complicate things, digital dermatitis may occur simultaneously with foot rot. Footbaths can be an effective treatment however there are logistical challenges when trying to use footbaths to treat large numbers of animals.

It was long thought that digital dermatitis was only a dairy cattle disease, however it is being increasingly diagnosed in confined beef cattle. A recent webinar discussed digital dermatitis in Ontario, where veterinarians are seeing the disease appear. This seems to be more common in pack barns compared to slatted barns (skip to 26:53).

An animal that has been sick over a longer period of time runs the risk of having the infection spread into bones or joints, making it very difficult to treat. For example, Mycoplasma bovis is commonly implicated in cases of pneumonia and mastitis. M. bovis can also travel through the animal’s bloodstream, sometimes settling in the ankle, stifle, hock, or elbow joints, leading to painful swelling and arthritis.

Histophilus somni is another organism that has been linked to arthritis. Unlike M bovis, there is a vaccine available for H somni.

Animals with joint infections may become chronically ill if they aren’t caught and treated in time, or if tissue damage compromises treatment. Pain management, and in severe cases, euthanasia may be required. Preventing the disease and learning to recognize these animals early on is the best strategy.

A swollen joint can cause lameness and become a serious health and welfare problem.

Laminitis is a condition where the lamellae, the layer of tissue between the hoof wall and the coffin bone, is weakened or becomes separated. Laminitis is linked to rumen acidosis which is when the rumen pH drops causing rumen bacteria to produce toxins that can pass through the rumen wall. These toxins can cause swelling in the blood vessels of the hooves, leading to founder or laminitis. Laminitis is usually attributed to diets that are high in fermentable carbohydrates such as grain, and it may occur after a sudden or rapid change in rations.

Laminitis may be more common in cattle that are held on feed too long and there is no practical treatment once an animal is afflicted, other than ensuring animals are kept on soft footing in pens that are well bedded.

Hoof elongation and curled claws can sometimes accompany severe cases of laminitis or founder.

Mycotoxin-related Necrosis

Mycotoxins in feed caused by ergot bodies or other fungi during wet growing conditions can lead to lameness. Ergot restricts blood flow to the hooves and other extremities which can cause severe lameness and even hoof-sloughing or other debilitating health and welfare issues. These animals often become chronically ill and require pain management or euthanasia. Prevent mycotoxin-related necrosis by feed testing to avoid or dilute mycotoxin-contaminated feeds. If caught early, this condition can be reversed by removing the contaminated feed source from the ration.

Accurate diagnosis is important for successful treatment and prevention of lameness. Veterinarians and researchers are beginning to learn more about common types of lameness including infectious causes such as toe tip necrosis and digital dermatitis. As new information emerges, producers and feedlot staff are learning how to identify and more accurately diagnose the differences between lameness diseases. Producers should not assume that all lame cattle have foot rot without close observation, to avoid unnecessary administration of antibiotics.

Pain management is an important consideration to improve both welfare and production outcomes in a lame animal. Some veterinarians and producers may use steroids, such as dexamethasone, as an anti-inflammatory in certain cases. The increased availability of non-steroidal anti-inflammatories (NSAIDs), such as meloxicam (i.e. Metacam®) or flunixin (i.e. Banamine®) have also helped to improve pain management in lame cattle.

Risk Factors

There are several risk factors that work alone or in conjunction with other factors that may lead to an increased incidence of lameness.

• Poor pen environments, including excessively frozen ground, very dry environments, or extremely wet and muddy conditions may negatively affect the skin barrier, leading to foot rot and other types of lameness.
• Housing cattle in pens where Fusobacterium necrophorum-caused foot rot has been a problem in the past can increase the risk of new infections.
• Poorly designed facilities, including slick surfaces or abrasive flooring, can cause hoof damage and leg injuries.
• Sharp edges, protrusions, or objects like wire, metal, rocks, ice, and frozen manure, can contribute to physical injuries break the skin barrier, allowing pathogens to enter the hoof area.
• Research has demonstrated that fall-placed calves are more at risk for lameness and injury than winter-placed calves or yearlings.
• Improper or high-stress animal handling practices can increase risk of slipping and physical injury.
• “Flighty” or nervous cattle are more likely to damage or injure their feet and legs.
• Cattle infected with Mycoplasma bovis are at risk of joint infection.
• High grain rations, erratic feed consumption (due to weather factors or feed supply problems), and improper feed processing are risk factors for laminitis.  
• Heavier cattle or cattle held on feed for too long are at a higher risk for lameness.

There are facility, health and behavioural management practices producers can employ to help reduce lameness, including:

• Regular pen cleaning and landscaping to ensure proper drainage, good footing, and to minimize build-up of manure and bacteria that causes lameness (i.e. Fusobacterium necrophorum);
• Disinfecting and maintaining hoof-trimming equipment and tools;
• Removing sharp objects, such as rocks, ice, wire or metal, that may cause injury;
• Vaccinating/preconditioning cattle to reduce disease and improve overall health and immunity in order to minimize risk of lameness as a secondary ailment;
• Practicing low-stress animal handling;
• Incorporating proper handling facility designs that include adequate traction and comfortable footing;
• Applying lime to barn floors following cleaning between fills to make the environmental pH less friendly to infectious lameness-causing bacteria;
• Consulting with your veterinarian regarding the potential use of a Fusobacterium necrophorum vaccine to prevent footrot;
• Incorporating step-up rations for high-grain diets to reduce the risk of acidosis and laminitis;
• Test feeds for potential mycotoxins that may lead to ergot poisoning;
• Carefully inspect feet and legs on breeding cattle to ensure they are fit and sound.

Learn More

Toe Tip Necrosis Syndrome (blog), Beef Cattle Research Council

Acidosis (web page), Beef Cattle Research Council

Mycotoxins (web page), Beef Cattle Research Council