Key Features that help in the Diagnosis of Lameness

If an animal has had an orthopaedic

A History of Trauma

If direct trauma has been witnessed by the owner or other reliable person and the lameness started immediately or soon afterwards a search for soft tissue, bone or peripheral nerve injury should be conducted. The central nervous system (brain and spinal cord) should also be thoroughly examined, and the possibility of potentially serious internal injuries must not be overlooked even though the animal may not be showing obvious clinical signs at the time of examination. As examples, following a road traffic accident signs of urine retention (due to damage to the bladder) or of a ruptured bladder may not become obvious for 6-12 hours after the trauma.

A History of Orthopaedic Disease

If an animal has had an orthopaedic problem in the past it is possible that a new episode of lameness could be related to the earlier condition - even though it could have occurred many months or even years before. For example, animals that have suffered from a bone fracture which involves a joint surface, ruptured ligaments or a joint dislocation may go on to develop degenerative joint disease, which can cause lameness later.

Sudden or Gradual onset Lameness

Sudden onset of lameness is often associated with trauma, foreign body penetrations or infection. Sometimes conditions that have been present for some time such as cancer or metabolic bone disease (e.g. secondary hyperparathyroidism) can also cause a sudden onset lameness due to local pain such as might result following bone destruction or fracture.

Localisation of pain, abnormal conformation, crepitus

It is important to determine if there is a local cause for the lameness, or if there is some form of systemic disease which could be responsible. A diligent examination of the affected limb(s) is essential to isolate local signs that can help determine the primary diagnosis. I prefer to start at the toes and work up the limb examining soft tissue, bones and joints in a systematic fashion (see performing an examination of a lame animal )

In relation to Lameness Pain and discomfort is caused by a variety of underlying changes in the limb :

Inflammation - due to physical injury, infection, cancer

Foreign body - the presence of a penetrating foreign body in limb, e.g. glass, wood, metal, grass awn.

Joint swelling - distension with fluid, joint dislocations

Fractures and soft tissue damage

 

Abnormal conformation can be due to several factors :

Fractures

Joint Dislocations - partial or complete

Soft tissue injury with swelling (e.g. haemorrhage or fluid accumulation)

Reduced soft tissue bulk, e.g. atrophy

Developmental abnormalities e.g. genetic inheritance, nutritional disorders

 

Crepitus is a term used to describe the noise and grating sensation that can be detected when abnormal articular joint surfaces or opposite edges at a fracture site are moved against each other

Breed

Many orthopaedic problems which may lead to lameness have a genetic basis and are more likely to occur in certain breeds. Large and giant breeds of dog are particularly susceptible to develop ruptured anterior cruciates and hip dysplasia.

Age

Some orthopaedic disorders are more likely to occur in young animals ( e.g. developmental abnormalities, hypertrophic osteodystrophy, ) whereas others are more likely to occur in older animals (e.g. degenerative joint disease, cancer - except for the malignant bone cancer osteosarcoma which is seen frequently in young large and giant breeds of dog.

Last updated : October 2013