Page 274 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.7a The axial skeleton – neck 249

VetBooks.ir MULTIPLE MYELOMA AND OTHER demarcated lucent zones within one or more verte-
NEOPLASTIC LESIONS
brae, usually without a rim of more radiopaque bone
Definition/overview (Fig. 1.471). Further information may be acquired
by CT or MRI. Haematological abnormalities asso-
Neoplastic lesions in the cervical region are rare. ciated with myeloma include anaemia, leucocytosis,
Primary bone lesions include multiple myeloma, neutrophilia and lymphocytosis. Total protein con-
osteosarcoma and lymphosarcoma. centration is very elevated. Protein electrophoresis
shows a monoclonal peak in the gamma region.
Aetiology/pathophysiology
Myeloma is a myeloproliferative disorder that can Management
cause radiolucent lesions in any bone, including the There is no treatment.
cervical vertebrae, and bone pain.

Clinical presentation BORRELIA BURGDORFERI
There is neck stiffness due to bone pain. If a tumour (SEE ALSO P. 217)
involves the vertebral canal, there may be ataxia.
Involvement of nerve roots may result in forelimb Definition/overview
lameness. Other systemic clinical signs may be pres- Many horses in tick-infested areas have a positive
ent depending on the nature of the primary tumour. antibody titre for Borrelia burgdorferi, but proven
cases of clinical disease are rare and are gener-
Differential diagnosis ally only seen in regions where human disease is
Osteomyelitis is the principal differential diagnosis. recognised.

Diagnosis Aetiology/pathophysiology
Diagnosis is based on radiological, haematological and B. burgdorferi may infiltrate nerve roots, spinal cord
bone biopsy examinations. There are usually clearly and brain.

1.471

Fig. 1.471 Laterolateral radiograph of the
occiput and first three cervical vertebrae of an
aged pony with recent onset ataxia. Cranial
is to the left. There is multifocal osteolysis
in the second cervical vertebra (arrows).
The differential diagnosis was neoplasia or Ce 3
osteomyelitis. Post-mortem examination
confirmed the presence of lymphosarcoma.
There was an extradural mass on the left
side of the spinal cord. (Photo courtesy
Lucy Meehan)