Claw lesion identification and recording is a key component of effective lameness reduction programs.

To help with record interpretation and treatment, it is important that records are kept to designate whether lesions are infectious or non-infectious in nature, as the corrective action plan for treatment of each type is very different.

More about infectious lesions
Infectious lesions include foot rot, digital dermatitis, interdigital dermatitis and generally heel erosion. Research shows that the primary risk factors associated with increased incidence of infectious lesions include:

• wet conditions

• poor foot hygiene

• presence of infected animals in the herd

A prerequisite for development of foot rot and digital dermatitis is local injury of the skin either between the claws or in the heel bulb region. This can be the result of a traumatic lesion caused by a foreign object or by maceration of skin by water, feces and urine. Thus keeping pens, pastures and lots dry, clean and free of foreign objects can substantially reduce incidence of infectious lesions on the dairy.

In most cases, promptly treating cows afflicted by foot rot with antibiotics, either topically or intramuscularly, results in very favorable cure rates. It is important to note that depending upon the antibiotic used and the means of application, this may represent extra-label use. Dairy producers are encouraged to work closely with their veterinarian to determine which antibiotic is most efficacious for treating each claw disorder, the correct dosage of the antibiotic, correct milk and meat withholding time and appropriate means of application.

The role of footbaths
When footbaths are used correctly, they can help prevent infectious lesions. However, when footbaths are used incorrectly, they can become a conduit for the transmission of infectious lesions. Research has shown that copper sulfate (5 to 10 percent solution), formaldehyde (three to five gallons of a 36 to 40 percent formalin solution per 100 gallons of footbath solution), zinc sulfate (5 to 20 percent solution) and some commercial products have been reported to help reduce incidence of infectious lesions. Table 1 provides a review of key factors to consider for maximizing the effectiveness of a footbath program.

Precautions regarding footbath use
While footbaths are appealing because they appear to require minimal amounts of labor, there are several very serious drawbacks to footbaths including:

• Use of copper or zinc sulfate in footbaths at the recommended strength, requires disposal of very large amounts of copper and zinc.

• Formaldehyde breaks down into carbon dioxide and water upon disposal. However, concerns with formaldehyde include:

1. It is a potential carcinogen.

2. Eye protection must be worn at all times when handling it.

3. Use of formaldehyde must be restricted to well-ventilated areas.

4. Formaldehyde may slow healing of open lesions.

There are several commercial footbath products being marketed that, when used as directed, substantially reduce the amount of disposed copper or zinc and are not suspected carcinogens. One drawback of many of these commercial products is that research on efficacy in controlling infectious lesions is limited or nonexistent, depending upon the product.

More about non-infectious lesions
Non-infectious claw lesions include toe, sole and heel ulcers, white line lesions, sole hemorrhages, double soles, thin soles and vertical and horizontal fissures. Similar to infectious lesions, development of non-infectious lesions is multi-factorial. For instance, thin soles can result from hoof trimmers removing excessive amount of claw horn. It can also be the result of cattle walking long distances on abrasive surfaces, resulting in horn wear exceeding the rate of horn growth. For reference, a review of key factors contributing to increased incidence of non-infectious lesions is provided in Table 2.

While there are many causes of non-infectious lesions, properly identifying the lesion as well as recording the zone in which the lesion occurs, will help the investigator determine the root cause. For instance, ulcers in the toe (zone 5) occur more commonly in cows with thin soles, while ulcers in the center of the sole (zone 4) are indicative of overgrown soles or excess standing time.

Final thoughts
Keep in mind, regardless of whether the lesion is non-infectious or infectious, one major factor contributing to lameness reduction success is the prompt and effective treatment of all lesions as early as possible. By recording which type of lesion occurs, producers can implement more targeted treatment plans, while also being able to track over time which type of lesions are most prevalent in their operation. PD

Socha, Tomlinson and DeFrain are dairy research nutritionists at Zinpro Corp. For more information about claw lesion identification, please visit www.zinpro.com/lameness

Michael T. Socha, Dana J. Tomlinson and J.M. DeFrain for Progressive Dairyman