Читать книгу Bovine Reproduction - Группа авторов - Страница 255

The prevalence of hoof cracks appears to be increasing, most likely related to genetics and intensive management. Subclinical laminitis has been suspected as an underlying cause in many of these cases. These cracks can affect one or multiple claws (Figure 16.13).

Figure 16.13 Vertical fissure in hoof wall due to subclinical laminitis.

Lameness is caused by instability in the hoof wall as weight is shifted to the wall. Debris and soil may be packed into the crack, inducing abscessation with encroachment on the sensitive lamina. Remove all debris through careful curettage. If any debris is left before immobilization, it can lead to sepsis of the laminae. If debridement of the crack results in penetration of the laminae, antibiotic bandages should be applied until the wound completely heals and the crack is dry and hard.

To stabilize a hoof crack, drill horizontally across the crack and place stainless‐steel wire across the defect in a bootlace pattern. Application of an acrylic compound into the crack and around the wire will bond the hoof. Alternatively, the crack can be filled with fiberglass cloth and acrylic compound that bonds to the hoof wall. This will bridge the crack and stabilize it, allowing new normal hoof wall to be produced at the coronary band. Newer products are now available that come with an applicator that allows direct application to the affected area without the need for any other material to support the repair.

If there is radiographic evidence of abscessation or osteomyelitis, open and debride the area to allow for healing. Curettage of the coffin bone and removal of bony fragments may have to be performed. To alleviate pain during movement, apply a hoof block to the healthy claw or consider using a splint. Systemic antibiotics are always indicated in situations involving deep sepsis of the hoof, and localized vascular perfusion can aid in increasing antibiotic concentrations within the area. Potassium penicillin, ampicillin, and tulathromycin are commonly used for vascular perfusion. Common side effects of tulathromycin include vasculitis and localized tissue edema. Medicated bandages, analgesics, and support bandaging of the contralateral limb should also be considered.