Lameness (Limping) in Dogs
Dr. Nicholas Trout
Careful history taking can be crucial in the diagnosis of many types of lameness. After noting your pets age, sex and breed and asking about general health issues, questions specific to the lameness may include:
a) How long has the problem been going on?
b) Is it getting better or worse?
c) Is it worse in the morning, worse at night, worse after rest, worse after exercise?
d) Does it wax and wane or remain constant?
e) Does your dog cry in pain?
f) Has it responded to any treatment?
Following a general physical examination your pet will be observed as he/she sits/stands in the examination room. For dogs it is common to observe walking and trotting. Sometimes owners find it helpful to bring along home videos of their pet's gait, particularly if the problem appears to come and go.
Orthopedic evaluation usually concentrates on examination of all four limbs, palpating the bones, muscles and joints for pain, swellings and decreased or abnormal ranges of motion. Your veterinarian may also focus on specific areas to look for certain causes of lameness in areas like the hip (hip dyplasia – Ortolani maneuver), elbow (elbow dysplasia) and stifle (cruciate disease – cranial drawer sign).
Your veterinarian will also manipulate the neck and palpate the spine along its length. If neurological disease is suspected a more detailed neurological examination will be necessary.
If an abnormality of bone or joint is detected on the examination, radiographs of that region may be taken. Radiographs are not always necessary, however, although they can be helpful to confirm a suspected diagnosis, to discover the exact diagnosis (say there is elbow pain but the exact cause could be one of several different problems with different treatment plans) or to give an owner a more accurate prognosis.
Sometimes, with more subtle problems, it is necessary to radiograph the opposite normal limb for the purposes of comparison. Radiographs may lead to a suspicion of a certain problem, but not definitive confirmation. In some cases, further x-rays of the same site, taken in another 4 to 6 weeks may be suggested, to see if the area of interest has changed or the lesion progressed after that time.
Radiographs may also suggest that other diagnostic tests are appropriate such as a biopsy or a joint tap. A joint tap involves the insertion of a sterile needle into a joint, with your pet either sedated or anesthetized. The fluid is evaluated to define the type of pathology present in the joint.
In certain challenging lameness cases, CT scans or MRI can be helpful, such as in the diagnosis of a subtle cruciate injury in the knee. Alternatively, arthroscopy, that is visualization of the inside of the joint using a small camera inserted into the joint, can be minimally invasive and allow diagnosis of certain joint diseases. This is a less invasive alternative to surgically opening the joint, and obviously there is less discomfort associated with arthroscopy.
Where neurological disease is suspected, specific diagnostic tests may include myelography, CT scan, MRI, and spinal taps.
On occasion, injection of a water-soluble dye into a joint, a procedure called arthrography, can be helpful to define the extent and shape of a joint. Problems of the biceps tendon that runs through a sheath in the shoulder joint can be demonstrated, in some cases, using this technique.
Use of bone scans has limited applications in the diagnosis of small animal lameness.
Most lameness problems do not produce a specific change that can be detected with routine blood work. However blood samples may be obtained where infectious or auto-immune causes are suspected, and in cases where an animal will undergo general anesthesia for surgical correction of the lameness.