By Dr. Michelle Arnold
There are many causes of lameness in beef cattle but nearly 90% of all lameness cases are due to something wrong in the foot. Since beef cattle producers generally make the initial diagnosis and treatment of lameness cases in their own cattle, it is important to establish assessment and treatment guidelines with your veterinarian so you will know when cases are failing to respond and in need of further examination. Although interdigital necrobacillosis (foot rot) is by far the most common hoof disorder in pastured beef cattle, it is not a condition to ignore and see if it gets better on its own. In fact, most disorders of the hoof, if not addressed quickly, can progress to a much more serious infection involving the bone, synovial structures, tendons and ligaments of the foot, collectively termed “deep digital sepsis”. Treatment at that advanced stage is expensive, radical and rarely successful.
One of the challenging aspects of discussing beef cattle lameness is the vocabulary utilized in bovine hoof anatomy (see Figure 1). A bovine “foot” is composed of two toes or “digits” that are typically referred to as “claws”. The claw is the constant interface between the animal and the environment. Each claw is covered by a rigid “hoof capsule”.
When viewing the hoof from the bottom, the “lateral claw” is the outside claw while the “medial claw” refers to the inside claw. The area in between the claws is the “interdigital space” and where the claws come together is termed the “interdigital cleft”. The “hoof wall” is by far the strongest and most important structure for weight bearing and is equivalent to the human fingernail. The “axial” wall is located in the interdigital space while the “abaxial” wall is located on the outer side of the claw. The “coronary band”, located at the hairline at the top of the hoof wall, is where the new horn grows from, and it takes about a year to reach the toe end. The “pastern” is the joint between the long cannon bone and the hoof. The “fetlock” is the joint above the pastern joint and is considered above the foot.
To begin the assessment of a newly discovered case of lameness, the first question to answer is whether the affected foot is swollen. Since the hoof capsule is rigid and unable to expand, swelling will be seen in the tissues immediately above the coronary band. Prior to assessment, moving the animal from deep grass or mud on to a solid surface and cleaning off any excessive dirt and debris will allow better visualization of the hoof. Start behind the animal, viewing the foot from the rear, and compare the distance between the dewclaws of the affected foot to that of the unaffected feet.
Source : osu.edu