Читать книгу Bovine Reproduction - Группа авторов - Страница 264

Osteochondrosis dissecans (OCD) is a common cause of lameness in cattle, particularly those being fitted for show, fed for sale, or being pushed for performance. It is often management induced in cattle with a genetic predisposition, particularly in club calves. Factors leading to OCD development include:

 Excessive feeding with subsequent excessive weight gain

 Lack of proper mineral supplementation leading to mineral imbalance, complicated by increased mineral requirements due to breed variances

 Feeding of distillate products with high sulfur content

 Lack of opportunity for skeletal maturity.

The most common location for OCD in the hindlimb is in the tarsus and the medial malleolus of the tibia; it develops less commonly on the lateral femoral condyle, the tibial plateau, and the medial and lateral trochlear ridges of the talus. In the forelimb, the primary site is the medial surface of the humeral condyle, though osteochondrosis can appear in any joint [17, 18] (Figures 16.24 and 16.25).

Figure 16.24 Osteochrondrosis lesion in a yearling bull from gain test. Notice the medical malleolar fragment (upper circle) and the cyst in the medial condyle of the talus.

Figure 16.25 Typical appearance of an OCD‐affected tarsus (boggy hock).

Surgical management of OCD and OCD fragments is preferred to slow down or stop the progression of inflammation and subsequent degeneration occurring within the affected joint. When anatomically possible, the OCD lesion should be debrided by curettage and overdrilling or implantation of a compression screw above the lesion (Figure 16.26).

Figure 16.26 Osteochrondrosis lesion in the talus of a show steer.

Medical management of cattle with OCD fragments is generally palliative in nature and often does not resolve the lameness, particularly in the growing animal. NSAIDs, stall rest, and intra‐articular injection of long‐acting anti‐inflammatories are utilized. However, as cattle get heavier and more weight is placed on the affected joint, clinical lameness may become worse.