Page 109 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition
P. 109

84                                        CHAPTER 1



  VetBooks.ir  1.144                                      1.145





























           Fig. 1.144  Intraoperative view of a large rounded   Fig. 1.145  Dorsoproximal/palmarodistal oblique
           keratoma immediately underneath the dorsal     radiographic view of the foot of a horse with a
           hoof wall (window resection). (Photo courtesy   keratoma at the toe of the distal phalanx. Note the
           John Peroni)                                   defect in the hoof wall immediately dorsal to the bony
                                                          lesion. (Photo courtesy Graham  Munroe)





           Differential diagnosis                         the use of advanced diagnostic imaging, explora-
           Other rare hoof tumours; chronic hoof wounds;   tion of the capsule may be warranted. A definitive
           abscess.                                       diagnosis requires a biopsy and histopathological
                                                          evaluation.
           Diagnosis
           Most horses with a keratoma present for a lameness  Management
           evaluation. A keratoma may be suspected if the   Keratomas that are not causing clinical signs may be
           lameness is associated with: a distorted hoof cap-  left untreated but monitored. The majority of cases
           sule and infection; a relatively well- circumscribed   that are brought to the clinician’s attention are caus-
           round or oval mass of horn is visible on the ground   ing signs and surgical excision (Fig. 1.146) is rec-
           surface of the foot, either in the white line of the   ommended. The tumours are excised through the
           distal wall or in the sole; or when a  dorsoproximal/   sole or a partial hoof wall resection, which can be
           palmarodistal oblique radiograph shows a well-  performed in the standing horse with sedation, peri-
           demarcated circular or oval area of lysis in the   neural analgesia and a tourniquet, or under general
           solar margin/parietal surface of the distal pha-  anaesthesia. The foot is bandaged, and the defect
           lanx (Fig. 1.145). In horses in which a tumour is   allowed to heal by secondary intention. Perioperative
           suspected but cannot be identified on the surface   antibiotics are advisable and may be continued if in
           of the hoof capsule, imaging with CT or MRI is   the course of excising the tumour, the dermis has
           effective at identifying the mass as well as planning   been disrupted as evidenced by haemorrhage into
           a surgical approach if needed. If expense precludes   the resected area.
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