Page 761 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

736 CHAPTER 4

VetBooks.ir Diagnosis examination and radiography the bone is rapid. Weight loss may ensue and atten-
oral
tive nursing of the patient is necessary to ensure that
Clinical
food ingestion is maintained. Growth rate slows
(Fig. 4.30).
after 9–12 months and the degree of correction is
Management more limited. Careful attention to incisor alignment
Orthodontic correction using tension band retarda- may be necessary during the animal’s life to prevent
tion of the growth of the incisive bone in combina- lesions on the mandibular gingiva from the impinge-
tion with bite plates is advised in the case of severe ment of the upper incisors.
defects. Maximum benefit is derived by early cor-
rection (from 1 to 3 months of age) while growth of CAMPYLORRHINUS
LATERALIS (WRY NOSE)
4.30
Definition/overview
Wry nose is a major congenital deformity of the face
(Fig. 4.31).

Aetiology/pathophysiology
The condition appears to be due to an asymmetric
dysplasia of the incisive bone and maxilla on one
side, which appears as a lateral deviation of the nos-
trils to the affected side. The deviation can involve
the nasal septum and the maxillary and palatine
bones. There is no breed predisposition and the
Fig. 4.30 Radiograph of a foal with Class 2
malocclusion resulting from mandibular brachygnathism heritability of the congenital condition is unproven,
(yellow arrows, upper jaw; red arrows, lower jaw). although Arab foals appear overrepresented. It has
been suggested that fetal malpositioning may be a
contributing factor.
4.31
Clinical presentation
The condition is immediately identifiable at birth by
clinical examination and can result in severe airflow
obstruction, incisor and premolar malocclusions
and difficulty in feeding. The foal should be care-
fully examined for other congenital abnormalities,
including axial and appendicular deformities.

Differential diagnosis
Brachygnathism, trauma.

Diagnosis
Clinical appearance and radiography. CT demon-
strates the extent of the lesions most thoroughly to
enable rational decisions on the foal’s viability.
Fig. 4.31 A Thoroughbred mare with wry nose,
which, unusually, has been reared and used for Management
breeding. Such animals do not appear consistently to Reconstructive surgery with osteotomy of the short-
produce offspring with the same defect. ened maxilla and palatine bone after elevation of